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  3. nRF5 action!

nRF5 action!

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  • NeverDieN Offline
    NeverDieN Offline
    NeverDie
    Hero Member
    wrote on last edited by
    #922

    Actually, there's another reason for wanting to avoid using the GPIO pins to intermediate waking up the MCU: earlier measurements in this thread showed that using the GPIO's in anything other than a "disconnected" state noticeably increases the current draw while sleeping.

    1 Reply Last reply
    0
    • d00616D d00616

      @d00616 said in nRF5 Bluetooth action!:

      Maybe someone has an idea about the reason. Here is my code for nRF5 and other with nRF24.

      Now, I have the NRF5_ESB working under MY_CORE_ONLY condition. The HFCLK is not initialized. I do some code changes to allow using the radio in core only mode.

      NeverDieN Offline
      NeverDieN Offline
      NeverDie
      Hero Member
      wrote on last edited by NeverDie
      #923

      @d00616 said in nRF5 Bluetooth action!:

      The HFCLK is not initialized.

      Not sure if it helps you at all, but to save extra energy I'm using the PPI to turn-on HFCLK before the Rx "listen-mode" begins, and then turn it off after the receiver is subsequently put to sleep:

        //Note: radio is assumed to be sleeping by this point, and with high frequency crystal oscillator turned off.
        NRF_PPI->CH[0].EEP = (uint32_t)&NRF_RTC0->EVENTS_OVRFLW;  //when COUNTER overflows.
        NRF_PPI->CH[0].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTART;  //turn-on the HF crystal oscillator
      
        NRF_PPI->CH[1].EEP = (uint32_t)&NRF_CLOCK->EVENTS_HFCLKSTARTED;  //After HF Clock started.
        NRF_PPI->CH[1].TEP = (uint32_t)&NRF_RADIO->TASKS_RXEN;  //turn on the radio receiver
      
        NRF_PPI->CH[2].EEP = (uint32_t)&NRF_RADIO->EVENTS_READY;  //After event READY, radio shall be in state RXIDLE.
        NRF_PPI->CH[2].TEP = (uint32_t)&NRF_RADIO->TASKS_START;  //Move from RXIDLE mode into RX mode.
      
        NRF_PPI->CH[3].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[0];  // If time to turn off the radio receiver
        NRF_PPI->CH[3].TEP = (uint32_t)&NRF_RADIO->TASKS_STOP; //Move radio from RX mode back into RXIDLE mode
        
        NRF_PPI->CH[4].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[1];  // If enough time has passed
        NRF_PPI->CH[4].TEP = (uint32_t)&NRF_RADIO->TASKS_DISABLE; //Sleep the radio
        NRF_PPI->FORK[4].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTOP; //Turn-off the high frequency crystal oscillator 
        
        NRF_PPI->CH[5].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[2];  // If 100ms has passed
        NRF_PPI->CH[5].TEP = (uint32_t)&NRF_RTC0->TASKS_TRIGOVRFLW; //Set COUNTER so that it will overflow in 16 ticks.
      
        NRF_PPI->CH[6].EEP = (uint32_t)&NRF_RADIO->EVENTS_END;  //packet received.
        NRF_PPI->CH[6].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[1]; //Make pin P0.18. be LOW (turn on the LED).
      
        NRF_PPI->CH[7].EEP = (uint32_t)&NRF_GPIOTE->EVENTS_IN[0];  //P0.16 pin change occured.
        NRF_PPI->CH[7].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[2]; //Make pin P0.17. be LOW (turn on the LED).
        
        NRF_PPI->CHENSET=B11111111; //enable Channels 7,6,5,4,3,2,1,and 0.
      

      It works. :)

      1 Reply Last reply
      1
      • NeverDieN Offline
        NeverDieN Offline
        NeverDie
        Hero Member
        wrote on last edited by NeverDie
        #924

        @d00616

        Can you see any reason as to why the radio isn't waking the MCU after it receives a packet? Here's the entire sketch:

        #include <nrf.h>
        //#include <MySensors.h>
        #include <RH_NRF51.h>
        
        // Singleton instance of the radio driver
        RH_NRF51 nrf51;
        
        bool toggle=true;
        uint32_t packetCounter=0;
        uint8_t myBuffer[20];  //required buffer for transmitting packet
        uint8_t my_default_network_address[] = {0xE7, 0xE7, 0xE7, 0xE7, 0xE7};
        
        bool mySetNetworkAddress(uint8_t* address, uint8_t len)
        {
            if (len < 3 || len > 5)
          return false;
        
            // First byte is the prefix, remainder are base
            NRF_RADIO->PREFIX0    = ((address[0] << RADIO_PREFIX0_AP0_Pos) & RADIO_PREFIX0_AP0_Msk);
            uint32_t base;
            memcpy(&base, address+1, len-1);
            NRF_RADIO->BASE0 = base;
        
            NRF_RADIO->PCNF1 =  (
          (((sizeof(myBuffer)) << RADIO_PCNF1_MAXLEN_Pos)  & RADIO_PCNF1_MAXLEN_Msk)  // maximum length of payload
          | (((0UL)        << RADIO_PCNF1_STATLEN_Pos) & RADIO_PCNF1_STATLEN_Msk) // expand the payload with 0 bytes
          | (((len-1)      << RADIO_PCNF1_BALEN_Pos)   & RADIO_PCNF1_BALEN_Msk)); // base address length in number of bytes.
        
            return true;
        }
        
        void myHwSleepPrepare(unsigned long ms)
        {
          // Idle serial device
          NRF_UART0->TASKS_STOPRX = 1;
          NRF_UART0->TASKS_STOPTX = 1;
          NRF_UART0->TASKS_SUSPEND = 1;
        
          //NRF_CLOCK->TASKS_HFCLKSTOP = 1;
          
          // Enable low power sleep mode
          NRF_POWER->TASKS_LOWPWR = 1;
        }
        
        // Sleep in System ON mode
        inline void doTheSleep()
        {
          __WFE();
          __SEV();
          __WFE();
        }
        
        void myHwSleepEnd(unsigned long ms)
        {
          // Start HFCLK
          //if (nrf5_pwr_hfclk) {
          if (false) {
            NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
            NRF_CLOCK->TASKS_HFCLKSTART = 1;
            while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
              ;
            // Enable low latency sleep mode
            NRF_POWER->TASKS_CONSTLAT = 1;
          }
        
           // Start serial device
        //#ifndef MY_DISABLED_SERIAL
          NRF_UART0->TASKS_STARTRX = 1;
          NRF_UART0->TASKS_STARTTX = 1;
        //#endif
        }
        
        void myHwSleep(unsigned long ms)
        {
          myHwSleepPrepare(ms);
          doTheSleep();
          //now sleeping
          myHwSleepEnd(ms);
        
        }
        
        
        
        void setup() {
          Serial.begin(250000);
          Serial.println();
          Serial.println("Starting...");
          Serial.flush();
        
          NRF_POWER->DCDCEN=1;  //enable the DCDC voltage regulator as the default.
          
          // Configure RTC
          NRF_RTC0->TASKS_STOP = 1;  //stop the RTC counter so that it can be configured without incident
        
          // Enable interrupt
          //NVIC_SetPriority(GPIOTE_IRQn, 15);
          //NVIC_ClearPendingIRQ(GPIOTE_IRQn);
          //NVIC_EnableIRQ(GPIOTE_IRQn);
          
          NVIC_SetPriority(RADIO_IRQn, 15);
          NVIC_ClearPendingIRQ(RADIO_IRQn);
          NVIC_EnableIRQ(RADIO_IRQn);
          NRF_RADIO->INTENSET = B1000;  //interrupt MCU if a packet is received.
          while (NRF_RADIO->INTENSET != B1000) {}  //wait until confirmed
              
          //NRF_GPIOTE->INTENSET = 1;  //interrupt MCU if change detected on pin P0.16.
          //while (NRF_GPIOTE->INTENSET != 1) {}  //wait until confirmed
          
          Serial.print("LFCLKSTAT=0X");
          Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
          Serial.flush();
        
          NRF_RADIO->FREQUENCY=123;
          NRF_RADIO->MODE=1;  //set 2Mbps datarate.
          NRF_RADIO->MODECNF0=1;  //enable fast ramp-up of radio from DISABLED state.
        
          if (!nrf51.init())
            Serial.println("init failed");
          mySetNetworkAddress(my_default_network_address, sizeof(my_default_network_address));   
          
          if ((NRF_CLOCK->LFCLKSTAT)>>2) {//if LF clock is running
            NRF_CLOCK->TASKS_LFCLKSTOP=1;  //stop the clock
            while ((NRF_CLOCK->LFCLKSTAT)& 1)  {}  //busy-wait until LF clock has stopped running
            Serial.println("LF clock is stopped.");
          }
        
          Serial.print("LFCLKSTAT=0x");
          Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
          Serial.flush();
          
          NRF_CLOCK->LFCLKSRC=1;  //use the crystal oscillator.
          while (!(NRF_CLOCK->LFCLKSRC=1)) {}  //
        
          Serial.println("Crystal oscillator is now the LF choice.");
          Serial.print("LFCLKSTAT=0x");
          Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
          Serial.flush();
         
          NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
        
        
          
          while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
          Serial.println("Low Frequency crystal oscillator started.");
          Serial.flush();
        
        
          Serial.print("LFCLKSTAT=0x");
          Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
          
          Serial.print("LFCLKSRC=0x");
          Serial.print(NRF_CLOCK->LFCLKSRC,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSRC,BIN);
          
          Serial.print("Present PRESCALER=");
          Serial.println(NRF_RTC0->PRESCALER);
        
          Serial.print("LFCLKSTAT=0x");
          Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
          Serial.print("=B");
          Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
          NRF_RTC0->PRESCALER=0;  //32768 frequency
          while (NRF_RTC0->PRESCALER!=0)  {}  //busy-wait until pre-scaler changes
          Serial.print("New PRESCALER=");
          Serial.println(NRF_RTC0->PRESCALER);
        
          Serial.println();
          Serial.println("Finished setup.");
          Serial.flush();
        
          //Radio enters RXIDLE soon after COUNTER overflows.
          NRF_RTC0->CC[0] = 24;  //the time to exit RX state.
          NRF_RTC0->CC[1] = 25;  //the time to put radio to sleep from RXIDLE
          NRF_RTC0->CC[2] = 3300;  //the time to restart the cycle
        
          NRF_RTC0->EVENTS_COMPARE[0] = 0;  //Clear the event flag.
          NRF_RTC0->EVENTS_COMPARE[1] = 0;  //Clear the event flag.
          NRF_RTC0->EVENTS_COMPARE[2] = 0;  //Clear the event flag.
            
          NRF_RADIO->TASKS_DISABLE=1;  //sleep the radio
          while (NRF_RADIO->STATE) {}; //wait until radio is DISABLED (i.e. STATE=0);
        
          //Configure GPIOTE 
          NRF_GPIOTE->CONFIG[0]=0x31001;  // Toggle Event; Pin P0.16; Event Mode 
                                          //So, any pin change on P0.16 will trigger an event.
                                           //On the Nordic nRF52 DK, Pin 0.16 is a button.
                                           
          NRF_GPIOTE->CONFIG[1]=0x131203;  //Initial setting: HIGH; Toggle Task; Pin P0.18; Task Mode
                                           //On the Nordic nRF52 DK, Pin 0.18 is an LED.
                                           //Note: initial setting of HIGH means that the LED will be initially OFF.
        
          NRF_GPIOTE->CONFIG[2]=0x131103;  //Initial setting: HIGH; Toggle Task; Pin P0.17; Task Mode
                                           //On the Nordic nRF52 DK, Pin P0.17 is an LED.
                                           //Note: initial setting of HIGH means that the LED will be initially OFF.          
        
          
          //Note: radio is assumed to be sleeping by this point, and with high frequency crystal oscillator turned off.
          NRF_PPI->CH[0].EEP = (uint32_t)&NRF_RTC0->EVENTS_OVRFLW;  //when COUNTER overflows.
          NRF_PPI->CH[0].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTART;  //turn on the HF crystal oscillator
        
          NRF_PPI->CH[1].EEP = (uint32_t)&NRF_CLOCK->EVENTS_HFCLKSTARTED;  //After HF Clock started.
          NRF_PPI->CH[1].TEP = (uint32_t)&NRF_RADIO->TASKS_RXEN;  //turn on the radio receiver
          //NRF_PPI->FORK[1].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[0]; //Make pin P0.18. be HIGH
        
        
          NRF_PPI->CH[2].EEP = (uint32_t)&NRF_RADIO->EVENTS_READY;  //After event READY, radio shall be in state RXIDLE.
          NRF_PPI->CH[2].TEP = (uint32_t)&NRF_RADIO->TASKS_START;  //Move from RXIDLE mode into RX mode.
        
          NRF_PPI->CH[3].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[0];  // If time to turn off the radio receiver
          NRF_PPI->CH[3].TEP = (uint32_t)&NRF_RADIO->TASKS_STOP; //Move radio from RX mode back into RXIDLE mode
          
          NRF_PPI->CH[4].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[1];  // If enough time has passed
          NRF_PPI->CH[4].TEP = (uint32_t)&NRF_RADIO->TASKS_DISABLE; //Sleep the radio
          NRF_PPI->FORK[4].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTOP; //Turn off the high frequency crystal oscillator 
          
          NRF_PPI->CH[5].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[2];  // If 100ms has passed
          NRF_PPI->CH[5].TEP = (uint32_t)&NRF_RTC0->TASKS_TRIGOVRFLW; //Set COUNTER so that it will overflow in 16 ticks.
        
          NRF_PPI->CH[6].EEP = (uint32_t)&NRF_RADIO->EVENTS_END;  //packet received.
          NRF_PPI->CH[6].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[1]; //Make pin P0.18. be LOW (turn on the LED).
        
          NRF_PPI->CH[7].EEP = (uint32_t)&NRF_GPIOTE->EVENTS_IN[0];  //P0.16 pin change occured.
          NRF_PPI->CH[7].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[2]; //Make pin P0.17. be LOW (turn on the LED).
          
          NRF_PPI->CHENSET=B11111111; //enable Channels 7,6,5,4,3,2,1,and 0.
          
          NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
          
          while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
          Serial.println("Crystal oscillator started.");
          Serial.flush();
        
          NRF_RTC0->EVTENSET=0x70003;  //enable routing of RTC TICK, OVRFLW, and comparison events to PPI for the comparisons
          while (NRF_RTC0->EVTEN!= (0x70003)) {};  //wait until EVTENSET setting is confirmed.
          
          NRF_RTC0->EVENTS_TICK=0;  //clear TICKS flag
          NRF_RTC0->EVENTS_OVRFLW=0;  //clear overflow flag
          NRF_RADIO->EVENTS_END=0;  //clear payload received flag.
        
          NRF_CLOCK->TASKS_HFCLKSTOP=1;  //Turn off the high frequency crystal oscillator.
          NRF_RTC0->TASKS_TRIGOVRFLW=1;  //prepare COUNTER so that an overflow will ensue in 16 ticks.
          while (NRF_RTC0->COUNTER!=0xFFFFF0) {} //wait until COUNTER is primed to overflow.
          NRF_RTC0->TASKS_START=1;  //  Resume the RTC, which had been paused.
          while ((NRF_RTC0->EVENTS_TICK==0)) {}  //wait until the radio is confirmed to be started.
        }
        uint32_t loopCounter=0;
        void loop() {
        
          
          Serial.print("time=");
          Serial.print(millis());
          Serial.print(", packetCounter=");
          Serial.println(packetCounter);
          
          Serial.flush();
          
          myHwSleep(500000000);  //sleep 100ms.  Already offset in setup by 1ms from wake-up of PPI.
        }
        
        
        // * Reset events and read back on nRF52
        //* http://infocenter.nordicsemi.com/pdf/nRF52_Series_Migration_v1.0.pdf
         
        #if __CORTEX_M == 0x04
        #define NRF5_RESET_EVENT(event)                                                 \
                event = 0;                                                                   \
                (void)event
        #else
        #define NRF5_RESET_EVENT(event) event = 0
        #endif
        
        
        // This must be in one line
        extern "C" { void RADIO_IRQHandler(void) {packetCounter++; NRF5_RESET_EVENT(NRF_RADIO->EVENTS_END); NRF_RADIO->EVENTS_END=0; }}
        
        
        

        The PPI does toggle an LED each time it receives a packet, but unfortunately the CPU remains asleep. Nonetheless, it does seem to follow your prescription for the ISR.

        U d00616D 2 Replies Last reply
        0
        • NeverDieN NeverDie

          @d00616

          Can you see any reason as to why the radio isn't waking the MCU after it receives a packet? Here's the entire sketch:

          #include <nrf.h>
          //#include <MySensors.h>
          #include <RH_NRF51.h>
          
          // Singleton instance of the radio driver
          RH_NRF51 nrf51;
          
          bool toggle=true;
          uint32_t packetCounter=0;
          uint8_t myBuffer[20];  //required buffer for transmitting packet
          uint8_t my_default_network_address[] = {0xE7, 0xE7, 0xE7, 0xE7, 0xE7};
          
          bool mySetNetworkAddress(uint8_t* address, uint8_t len)
          {
              if (len < 3 || len > 5)
            return false;
          
              // First byte is the prefix, remainder are base
              NRF_RADIO->PREFIX0    = ((address[0] << RADIO_PREFIX0_AP0_Pos) & RADIO_PREFIX0_AP0_Msk);
              uint32_t base;
              memcpy(&base, address+1, len-1);
              NRF_RADIO->BASE0 = base;
          
              NRF_RADIO->PCNF1 =  (
            (((sizeof(myBuffer)) << RADIO_PCNF1_MAXLEN_Pos)  & RADIO_PCNF1_MAXLEN_Msk)  // maximum length of payload
            | (((0UL)        << RADIO_PCNF1_STATLEN_Pos) & RADIO_PCNF1_STATLEN_Msk) // expand the payload with 0 bytes
            | (((len-1)      << RADIO_PCNF1_BALEN_Pos)   & RADIO_PCNF1_BALEN_Msk)); // base address length in number of bytes.
          
              return true;
          }
          
          void myHwSleepPrepare(unsigned long ms)
          {
            // Idle serial device
            NRF_UART0->TASKS_STOPRX = 1;
            NRF_UART0->TASKS_STOPTX = 1;
            NRF_UART0->TASKS_SUSPEND = 1;
          
            //NRF_CLOCK->TASKS_HFCLKSTOP = 1;
            
            // Enable low power sleep mode
            NRF_POWER->TASKS_LOWPWR = 1;
          }
          
          // Sleep in System ON mode
          inline void doTheSleep()
          {
            __WFE();
            __SEV();
            __WFE();
          }
          
          void myHwSleepEnd(unsigned long ms)
          {
            // Start HFCLK
            //if (nrf5_pwr_hfclk) {
            if (false) {
              NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
              NRF_CLOCK->TASKS_HFCLKSTART = 1;
              while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
                ;
              // Enable low latency sleep mode
              NRF_POWER->TASKS_CONSTLAT = 1;
            }
          
             // Start serial device
          //#ifndef MY_DISABLED_SERIAL
            NRF_UART0->TASKS_STARTRX = 1;
            NRF_UART0->TASKS_STARTTX = 1;
          //#endif
          }
          
          void myHwSleep(unsigned long ms)
          {
            myHwSleepPrepare(ms);
            doTheSleep();
            //now sleeping
            myHwSleepEnd(ms);
          
          }
          
          
          
          void setup() {
            Serial.begin(250000);
            Serial.println();
            Serial.println("Starting...");
            Serial.flush();
          
            NRF_POWER->DCDCEN=1;  //enable the DCDC voltage regulator as the default.
            
            // Configure RTC
            NRF_RTC0->TASKS_STOP = 1;  //stop the RTC counter so that it can be configured without incident
          
            // Enable interrupt
            //NVIC_SetPriority(GPIOTE_IRQn, 15);
            //NVIC_ClearPendingIRQ(GPIOTE_IRQn);
            //NVIC_EnableIRQ(GPIOTE_IRQn);
            
            NVIC_SetPriority(RADIO_IRQn, 15);
            NVIC_ClearPendingIRQ(RADIO_IRQn);
            NVIC_EnableIRQ(RADIO_IRQn);
            NRF_RADIO->INTENSET = B1000;  //interrupt MCU if a packet is received.
            while (NRF_RADIO->INTENSET != B1000) {}  //wait until confirmed
                
            //NRF_GPIOTE->INTENSET = 1;  //interrupt MCU if change detected on pin P0.16.
            //while (NRF_GPIOTE->INTENSET != 1) {}  //wait until confirmed
            
            Serial.print("LFCLKSTAT=0X");
            Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
            Serial.flush();
          
            NRF_RADIO->FREQUENCY=123;
            NRF_RADIO->MODE=1;  //set 2Mbps datarate.
            NRF_RADIO->MODECNF0=1;  //enable fast ramp-up of radio from DISABLED state.
          
            if (!nrf51.init())
              Serial.println("init failed");
            mySetNetworkAddress(my_default_network_address, sizeof(my_default_network_address));   
            
            if ((NRF_CLOCK->LFCLKSTAT)>>2) {//if LF clock is running
              NRF_CLOCK->TASKS_LFCLKSTOP=1;  //stop the clock
              while ((NRF_CLOCK->LFCLKSTAT)& 1)  {}  //busy-wait until LF clock has stopped running
              Serial.println("LF clock is stopped.");
            }
          
            Serial.print("LFCLKSTAT=0x");
            Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
            Serial.flush();
            
            NRF_CLOCK->LFCLKSRC=1;  //use the crystal oscillator.
            while (!(NRF_CLOCK->LFCLKSRC=1)) {}  //
          
            Serial.println("Crystal oscillator is now the LF choice.");
            Serial.print("LFCLKSTAT=0x");
            Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
            Serial.flush();
           
            NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
          
          
            
            while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
            Serial.println("Low Frequency crystal oscillator started.");
            Serial.flush();
          
          
            Serial.print("LFCLKSTAT=0x");
            Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
            
            Serial.print("LFCLKSRC=0x");
            Serial.print(NRF_CLOCK->LFCLKSRC,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSRC,BIN);
            
            Serial.print("Present PRESCALER=");
            Serial.println(NRF_RTC0->PRESCALER);
          
            Serial.print("LFCLKSTAT=0x");
            Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
            Serial.print("=B");
            Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
            NRF_RTC0->PRESCALER=0;  //32768 frequency
            while (NRF_RTC0->PRESCALER!=0)  {}  //busy-wait until pre-scaler changes
            Serial.print("New PRESCALER=");
            Serial.println(NRF_RTC0->PRESCALER);
          
            Serial.println();
            Serial.println("Finished setup.");
            Serial.flush();
          
            //Radio enters RXIDLE soon after COUNTER overflows.
            NRF_RTC0->CC[0] = 24;  //the time to exit RX state.
            NRF_RTC0->CC[1] = 25;  //the time to put radio to sleep from RXIDLE
            NRF_RTC0->CC[2] = 3300;  //the time to restart the cycle
          
            NRF_RTC0->EVENTS_COMPARE[0] = 0;  //Clear the event flag.
            NRF_RTC0->EVENTS_COMPARE[1] = 0;  //Clear the event flag.
            NRF_RTC0->EVENTS_COMPARE[2] = 0;  //Clear the event flag.
              
            NRF_RADIO->TASKS_DISABLE=1;  //sleep the radio
            while (NRF_RADIO->STATE) {}; //wait until radio is DISABLED (i.e. STATE=0);
          
            //Configure GPIOTE 
            NRF_GPIOTE->CONFIG[0]=0x31001;  // Toggle Event; Pin P0.16; Event Mode 
                                            //So, any pin change on P0.16 will trigger an event.
                                             //On the Nordic nRF52 DK, Pin 0.16 is a button.
                                             
            NRF_GPIOTE->CONFIG[1]=0x131203;  //Initial setting: HIGH; Toggle Task; Pin P0.18; Task Mode
                                             //On the Nordic nRF52 DK, Pin 0.18 is an LED.
                                             //Note: initial setting of HIGH means that the LED will be initially OFF.
          
            NRF_GPIOTE->CONFIG[2]=0x131103;  //Initial setting: HIGH; Toggle Task; Pin P0.17; Task Mode
                                             //On the Nordic nRF52 DK, Pin P0.17 is an LED.
                                             //Note: initial setting of HIGH means that the LED will be initially OFF.          
          
            
            //Note: radio is assumed to be sleeping by this point, and with high frequency crystal oscillator turned off.
            NRF_PPI->CH[0].EEP = (uint32_t)&NRF_RTC0->EVENTS_OVRFLW;  //when COUNTER overflows.
            NRF_PPI->CH[0].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTART;  //turn on the HF crystal oscillator
          
            NRF_PPI->CH[1].EEP = (uint32_t)&NRF_CLOCK->EVENTS_HFCLKSTARTED;  //After HF Clock started.
            NRF_PPI->CH[1].TEP = (uint32_t)&NRF_RADIO->TASKS_RXEN;  //turn on the radio receiver
            //NRF_PPI->FORK[1].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[0]; //Make pin P0.18. be HIGH
          
          
            NRF_PPI->CH[2].EEP = (uint32_t)&NRF_RADIO->EVENTS_READY;  //After event READY, radio shall be in state RXIDLE.
            NRF_PPI->CH[2].TEP = (uint32_t)&NRF_RADIO->TASKS_START;  //Move from RXIDLE mode into RX mode.
          
            NRF_PPI->CH[3].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[0];  // If time to turn off the radio receiver
            NRF_PPI->CH[3].TEP = (uint32_t)&NRF_RADIO->TASKS_STOP; //Move radio from RX mode back into RXIDLE mode
            
            NRF_PPI->CH[4].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[1];  // If enough time has passed
            NRF_PPI->CH[4].TEP = (uint32_t)&NRF_RADIO->TASKS_DISABLE; //Sleep the radio
            NRF_PPI->FORK[4].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTOP; //Turn off the high frequency crystal oscillator 
            
            NRF_PPI->CH[5].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[2];  // If 100ms has passed
            NRF_PPI->CH[5].TEP = (uint32_t)&NRF_RTC0->TASKS_TRIGOVRFLW; //Set COUNTER so that it will overflow in 16 ticks.
          
            NRF_PPI->CH[6].EEP = (uint32_t)&NRF_RADIO->EVENTS_END;  //packet received.
            NRF_PPI->CH[6].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[1]; //Make pin P0.18. be LOW (turn on the LED).
          
            NRF_PPI->CH[7].EEP = (uint32_t)&NRF_GPIOTE->EVENTS_IN[0];  //P0.16 pin change occured.
            NRF_PPI->CH[7].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[2]; //Make pin P0.17. be LOW (turn on the LED).
            
            NRF_PPI->CHENSET=B11111111; //enable Channels 7,6,5,4,3,2,1,and 0.
            
            NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
            
            while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
            Serial.println("Crystal oscillator started.");
            Serial.flush();
          
            NRF_RTC0->EVTENSET=0x70003;  //enable routing of RTC TICK, OVRFLW, and comparison events to PPI for the comparisons
            while (NRF_RTC0->EVTEN!= (0x70003)) {};  //wait until EVTENSET setting is confirmed.
            
            NRF_RTC0->EVENTS_TICK=0;  //clear TICKS flag
            NRF_RTC0->EVENTS_OVRFLW=0;  //clear overflow flag
            NRF_RADIO->EVENTS_END=0;  //clear payload received flag.
          
            NRF_CLOCK->TASKS_HFCLKSTOP=1;  //Turn off the high frequency crystal oscillator.
            NRF_RTC0->TASKS_TRIGOVRFLW=1;  //prepare COUNTER so that an overflow will ensue in 16 ticks.
            while (NRF_RTC0->COUNTER!=0xFFFFF0) {} //wait until COUNTER is primed to overflow.
            NRF_RTC0->TASKS_START=1;  //  Resume the RTC, which had been paused.
            while ((NRF_RTC0->EVENTS_TICK==0)) {}  //wait until the radio is confirmed to be started.
          }
          uint32_t loopCounter=0;
          void loop() {
          
            
            Serial.print("time=");
            Serial.print(millis());
            Serial.print(", packetCounter=");
            Serial.println(packetCounter);
            
            Serial.flush();
            
            myHwSleep(500000000);  //sleep 100ms.  Already offset in setup by 1ms from wake-up of PPI.
          }
          
          
          // * Reset events and read back on nRF52
          //* http://infocenter.nordicsemi.com/pdf/nRF52_Series_Migration_v1.0.pdf
           
          #if __CORTEX_M == 0x04
          #define NRF5_RESET_EVENT(event)                                                 \
                  event = 0;                                                                   \
                  (void)event
          #else
          #define NRF5_RESET_EVENT(event) event = 0
          #endif
          
          
          // This must be in one line
          extern "C" { void RADIO_IRQHandler(void) {packetCounter++; NRF5_RESET_EVENT(NRF_RADIO->EVENTS_END); NRF_RADIO->EVENTS_END=0; }}
          
          
          

          The PPI does toggle an LED each time it receives a packet, but unfortunately the CPU remains asleep. Nonetheless, it does seem to follow your prescription for the ISR.

          U Offline
          U Offline
          Uhrheber
          wrote on last edited by
          #925

          @NeverDie
          What if you activate a pin change interrupt/wake at the pin the PPI toggles?
          Or connect it to another pin with pin change wake?

          NeverDieN 1 Reply Last reply
          0
          • U Uhrheber

            @NeverDie
            What if you activate a pin change interrupt/wake at the pin the PPI toggles?
            Or connect it to another pin with pin change wake?

            NeverDieN Offline
            NeverDieN Offline
            NeverDie
            Hero Member
            wrote on last edited by
            #926

            @Uhrheber said in nRF5 Bluetooth action!:

            @NeverDie
            What if you activate a pin change interrupt/wake at the pin the PPI toggles?
            Or connect it to another pin with pin change wake?

            Yes, I have tested that as a workaround. It "works", but using GPIO pins increases the current drain.

            1 Reply Last reply
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            • NeverDieN Offline
              NeverDieN Offline
              NeverDie
              Hero Member
              wrote on last edited by NeverDie
              #927

              Well, I guess it's almost moot now, because I found and tested a better workaround. I re-wrote the PPI code so that after packet receipt, the PPI triggers an RTC0 overflow. It is that which is then used to wake-up the MCU. No GPIO pins need be involved, so no propagation delays and no increase in current drawn. It works.

              I still think the radio ISR code (above) should have worked, but fortunately that's no longer holding me back now that I have a good enough workaround. :)

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              • NeverDieN Offline
                NeverDieN Offline
                NeverDie
                Hero Member
                wrote on last edited by NeverDie
                #928

                However, there's one fly in the ointment remaining. It turns out that some other timer is sometimes waking up the CPU:

                time=15798, Radio STATE=0, COUNTER=0x49, packetCounter=22
                time=15900, Radio STATE=0, COUNTER=0x49, packetCounter=23
                time=16001, Radio STATE=0, COUNTER=0x49, packetCounter=24
                time=16103, Radio STATE=0, COUNTER=0x49, packetCounter=25
                time=16204, Radio STATE=0, COUNTER=0x49, packetCounter=26
                time=16306, Radio STATE=0, COUNTER=0x49, packetCounter=27
                time=512000, Radio STATE=0, COUNTER=0x2035, packetCounter=27
                time=1024000, Radio STATE=0, COUNTER=0x269, packetCounter=27
                time=1536000, Radio STATE=0, COUNTER=0x1803, packetCounter=27
                time=2048000, Radio STATE=3, COUNTER=0x36, packetCounter=27
                time=2560000, Radio STATE=0, COUNTER=0x1570, packetCounter=27
                time=3072000, Radio STATE=0, COUNTER=0x3104, packetCounter=27
                time=3584000, Radio STATE=0, COUNTER=0x1337, packetCounter=27
                time=4096000, Radio STATE=0, COUNTER=0x2871, packetCounter=27
                time=4608000, Radio STATE=0, COUNTER=0x1104, packetCounter=27
                time=5120000, Radio STATE=0, COUNTER=0x2638, packetCounter=27
                

                All the lines labelled packetCounter=27 (after the first one that is) are a result of this. Looking at the time, they appear to happen on the rollover of some other timer (?)--apparently the one that is responsible for keeping track of millis(). I can filter them out after-the-fact, but I'd rather they not be waking up the CPU for no reason, as that is just a waste of energy.

                NeverDieN 1 Reply Last reply
                0
                • NeverDieN NeverDie

                  @d00616

                  Can you see any reason as to why the radio isn't waking the MCU after it receives a packet? Here's the entire sketch:

                  #include <nrf.h>
                  //#include <MySensors.h>
                  #include <RH_NRF51.h>
                  
                  // Singleton instance of the radio driver
                  RH_NRF51 nrf51;
                  
                  bool toggle=true;
                  uint32_t packetCounter=0;
                  uint8_t myBuffer[20];  //required buffer for transmitting packet
                  uint8_t my_default_network_address[] = {0xE7, 0xE7, 0xE7, 0xE7, 0xE7};
                  
                  bool mySetNetworkAddress(uint8_t* address, uint8_t len)
                  {
                      if (len < 3 || len > 5)
                    return false;
                  
                      // First byte is the prefix, remainder are base
                      NRF_RADIO->PREFIX0    = ((address[0] << RADIO_PREFIX0_AP0_Pos) & RADIO_PREFIX0_AP0_Msk);
                      uint32_t base;
                      memcpy(&base, address+1, len-1);
                      NRF_RADIO->BASE0 = base;
                  
                      NRF_RADIO->PCNF1 =  (
                    (((sizeof(myBuffer)) << RADIO_PCNF1_MAXLEN_Pos)  & RADIO_PCNF1_MAXLEN_Msk)  // maximum length of payload
                    | (((0UL)        << RADIO_PCNF1_STATLEN_Pos) & RADIO_PCNF1_STATLEN_Msk) // expand the payload with 0 bytes
                    | (((len-1)      << RADIO_PCNF1_BALEN_Pos)   & RADIO_PCNF1_BALEN_Msk)); // base address length in number of bytes.
                  
                      return true;
                  }
                  
                  void myHwSleepPrepare(unsigned long ms)
                  {
                    // Idle serial device
                    NRF_UART0->TASKS_STOPRX = 1;
                    NRF_UART0->TASKS_STOPTX = 1;
                    NRF_UART0->TASKS_SUSPEND = 1;
                  
                    //NRF_CLOCK->TASKS_HFCLKSTOP = 1;
                    
                    // Enable low power sleep mode
                    NRF_POWER->TASKS_LOWPWR = 1;
                  }
                  
                  // Sleep in System ON mode
                  inline void doTheSleep()
                  {
                    __WFE();
                    __SEV();
                    __WFE();
                  }
                  
                  void myHwSleepEnd(unsigned long ms)
                  {
                    // Start HFCLK
                    //if (nrf5_pwr_hfclk) {
                    if (false) {
                      NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
                      NRF_CLOCK->TASKS_HFCLKSTART = 1;
                      while (NRF_CLOCK->EVENTS_HFCLKSTARTED == 0)
                        ;
                      // Enable low latency sleep mode
                      NRF_POWER->TASKS_CONSTLAT = 1;
                    }
                  
                     // Start serial device
                  //#ifndef MY_DISABLED_SERIAL
                    NRF_UART0->TASKS_STARTRX = 1;
                    NRF_UART0->TASKS_STARTTX = 1;
                  //#endif
                  }
                  
                  void myHwSleep(unsigned long ms)
                  {
                    myHwSleepPrepare(ms);
                    doTheSleep();
                    //now sleeping
                    myHwSleepEnd(ms);
                  
                  }
                  
                  
                  
                  void setup() {
                    Serial.begin(250000);
                    Serial.println();
                    Serial.println("Starting...");
                    Serial.flush();
                  
                    NRF_POWER->DCDCEN=1;  //enable the DCDC voltage regulator as the default.
                    
                    // Configure RTC
                    NRF_RTC0->TASKS_STOP = 1;  //stop the RTC counter so that it can be configured without incident
                  
                    // Enable interrupt
                    //NVIC_SetPriority(GPIOTE_IRQn, 15);
                    //NVIC_ClearPendingIRQ(GPIOTE_IRQn);
                    //NVIC_EnableIRQ(GPIOTE_IRQn);
                    
                    NVIC_SetPriority(RADIO_IRQn, 15);
                    NVIC_ClearPendingIRQ(RADIO_IRQn);
                    NVIC_EnableIRQ(RADIO_IRQn);
                    NRF_RADIO->INTENSET = B1000;  //interrupt MCU if a packet is received.
                    while (NRF_RADIO->INTENSET != B1000) {}  //wait until confirmed
                        
                    //NRF_GPIOTE->INTENSET = 1;  //interrupt MCU if change detected on pin P0.16.
                    //while (NRF_GPIOTE->INTENSET != 1) {}  //wait until confirmed
                    
                    Serial.print("LFCLKSTAT=0X");
                    Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
                    Serial.flush();
                  
                    NRF_RADIO->FREQUENCY=123;
                    NRF_RADIO->MODE=1;  //set 2Mbps datarate.
                    NRF_RADIO->MODECNF0=1;  //enable fast ramp-up of radio from DISABLED state.
                  
                    if (!nrf51.init())
                      Serial.println("init failed");
                    mySetNetworkAddress(my_default_network_address, sizeof(my_default_network_address));   
                    
                    if ((NRF_CLOCK->LFCLKSTAT)>>2) {//if LF clock is running
                      NRF_CLOCK->TASKS_LFCLKSTOP=1;  //stop the clock
                      while ((NRF_CLOCK->LFCLKSTAT)& 1)  {}  //busy-wait until LF clock has stopped running
                      Serial.println("LF clock is stopped.");
                    }
                  
                    Serial.print("LFCLKSTAT=0x");
                    Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
                    Serial.flush();
                    
                    NRF_CLOCK->LFCLKSRC=1;  //use the crystal oscillator.
                    while (!(NRF_CLOCK->LFCLKSRC=1)) {}  //
                  
                    Serial.println("Crystal oscillator is now the LF choice.");
                    Serial.print("LFCLKSTAT=0x");
                    Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
                    Serial.flush();
                   
                    NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
                  
                  
                    
                    while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
                    Serial.println("Low Frequency crystal oscillator started.");
                    Serial.flush();
                  
                  
                    Serial.print("LFCLKSTAT=0x");
                    Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
                    
                    Serial.print("LFCLKSRC=0x");
                    Serial.print(NRF_CLOCK->LFCLKSRC,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSRC,BIN);
                    
                    Serial.print("Present PRESCALER=");
                    Serial.println(NRF_RTC0->PRESCALER);
                  
                    Serial.print("LFCLKSTAT=0x");
                    Serial.print(NRF_CLOCK->LFCLKSTAT,HEX);
                    Serial.print("=B");
                    Serial.println(NRF_CLOCK->LFCLKSTAT,BIN);
                    NRF_RTC0->PRESCALER=0;  //32768 frequency
                    while (NRF_RTC0->PRESCALER!=0)  {}  //busy-wait until pre-scaler changes
                    Serial.print("New PRESCALER=");
                    Serial.println(NRF_RTC0->PRESCALER);
                  
                    Serial.println();
                    Serial.println("Finished setup.");
                    Serial.flush();
                  
                    //Radio enters RXIDLE soon after COUNTER overflows.
                    NRF_RTC0->CC[0] = 24;  //the time to exit RX state.
                    NRF_RTC0->CC[1] = 25;  //the time to put radio to sleep from RXIDLE
                    NRF_RTC0->CC[2] = 3300;  //the time to restart the cycle
                  
                    NRF_RTC0->EVENTS_COMPARE[0] = 0;  //Clear the event flag.
                    NRF_RTC0->EVENTS_COMPARE[1] = 0;  //Clear the event flag.
                    NRF_RTC0->EVENTS_COMPARE[2] = 0;  //Clear the event flag.
                      
                    NRF_RADIO->TASKS_DISABLE=1;  //sleep the radio
                    while (NRF_RADIO->STATE) {}; //wait until radio is DISABLED (i.e. STATE=0);
                  
                    //Configure GPIOTE 
                    NRF_GPIOTE->CONFIG[0]=0x31001;  // Toggle Event; Pin P0.16; Event Mode 
                                                    //So, any pin change on P0.16 will trigger an event.
                                                     //On the Nordic nRF52 DK, Pin 0.16 is a button.
                                                     
                    NRF_GPIOTE->CONFIG[1]=0x131203;  //Initial setting: HIGH; Toggle Task; Pin P0.18; Task Mode
                                                     //On the Nordic nRF52 DK, Pin 0.18 is an LED.
                                                     //Note: initial setting of HIGH means that the LED will be initially OFF.
                  
                    NRF_GPIOTE->CONFIG[2]=0x131103;  //Initial setting: HIGH; Toggle Task; Pin P0.17; Task Mode
                                                     //On the Nordic nRF52 DK, Pin P0.17 is an LED.
                                                     //Note: initial setting of HIGH means that the LED will be initially OFF.          
                  
                    
                    //Note: radio is assumed to be sleeping by this point, and with high frequency crystal oscillator turned off.
                    NRF_PPI->CH[0].EEP = (uint32_t)&NRF_RTC0->EVENTS_OVRFLW;  //when COUNTER overflows.
                    NRF_PPI->CH[0].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTART;  //turn on the HF crystal oscillator
                  
                    NRF_PPI->CH[1].EEP = (uint32_t)&NRF_CLOCK->EVENTS_HFCLKSTARTED;  //After HF Clock started.
                    NRF_PPI->CH[1].TEP = (uint32_t)&NRF_RADIO->TASKS_RXEN;  //turn on the radio receiver
                    //NRF_PPI->FORK[1].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[0]; //Make pin P0.18. be HIGH
                  
                  
                    NRF_PPI->CH[2].EEP = (uint32_t)&NRF_RADIO->EVENTS_READY;  //After event READY, radio shall be in state RXIDLE.
                    NRF_PPI->CH[2].TEP = (uint32_t)&NRF_RADIO->TASKS_START;  //Move from RXIDLE mode into RX mode.
                  
                    NRF_PPI->CH[3].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[0];  // If time to turn off the radio receiver
                    NRF_PPI->CH[3].TEP = (uint32_t)&NRF_RADIO->TASKS_STOP; //Move radio from RX mode back into RXIDLE mode
                    
                    NRF_PPI->CH[4].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[1];  // If enough time has passed
                    NRF_PPI->CH[4].TEP = (uint32_t)&NRF_RADIO->TASKS_DISABLE; //Sleep the radio
                    NRF_PPI->FORK[4].TEP = (uint32_t)&NRF_CLOCK->TASKS_HFCLKSTOP; //Turn off the high frequency crystal oscillator 
                    
                    NRF_PPI->CH[5].EEP = (uint32_t)&NRF_RTC0->EVENTS_COMPARE[2];  // If 100ms has passed
                    NRF_PPI->CH[5].TEP = (uint32_t)&NRF_RTC0->TASKS_TRIGOVRFLW; //Set COUNTER so that it will overflow in 16 ticks.
                  
                    NRF_PPI->CH[6].EEP = (uint32_t)&NRF_RADIO->EVENTS_END;  //packet received.
                    NRF_PPI->CH[6].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[1]; //Make pin P0.18. be LOW (turn on the LED).
                  
                    NRF_PPI->CH[7].EEP = (uint32_t)&NRF_GPIOTE->EVENTS_IN[0];  //P0.16 pin change occured.
                    NRF_PPI->CH[7].TEP = (uint32_t)&NRF_GPIOTE->TASKS_OUT[2]; //Make pin P0.17. be LOW (turn on the LED).
                    
                    NRF_PPI->CHENSET=B11111111; //enable Channels 7,6,5,4,3,2,1,and 0.
                    
                    NRF_CLOCK->TASKS_LFCLKSTART=1;  //start the crystal oscillator clock
                    
                    while (!(NRF_CLOCK->EVENTS_LFCLKSTARTED)) {}  //busy-wait until the clock is confirmed started.
                    Serial.println("Crystal oscillator started.");
                    Serial.flush();
                  
                    NRF_RTC0->EVTENSET=0x70003;  //enable routing of RTC TICK, OVRFLW, and comparison events to PPI for the comparisons
                    while (NRF_RTC0->EVTEN!= (0x70003)) {};  //wait until EVTENSET setting is confirmed.
                    
                    NRF_RTC0->EVENTS_TICK=0;  //clear TICKS flag
                    NRF_RTC0->EVENTS_OVRFLW=0;  //clear overflow flag
                    NRF_RADIO->EVENTS_END=0;  //clear payload received flag.
                  
                    NRF_CLOCK->TASKS_HFCLKSTOP=1;  //Turn off the high frequency crystal oscillator.
                    NRF_RTC0->TASKS_TRIGOVRFLW=1;  //prepare COUNTER so that an overflow will ensue in 16 ticks.
                    while (NRF_RTC0->COUNTER!=0xFFFFF0) {} //wait until COUNTER is primed to overflow.
                    NRF_RTC0->TASKS_START=1;  //  Resume the RTC, which had been paused.
                    while ((NRF_RTC0->EVENTS_TICK==0)) {}  //wait until the radio is confirmed to be started.
                  }
                  uint32_t loopCounter=0;
                  void loop() {
                  
                    
                    Serial.print("time=");
                    Serial.print(millis());
                    Serial.print(", packetCounter=");
                    Serial.println(packetCounter);
                    
                    Serial.flush();
                    
                    myHwSleep(500000000);  //sleep 100ms.  Already offset in setup by 1ms from wake-up of PPI.
                  }
                  
                  
                  // * Reset events and read back on nRF52
                  //* http://infocenter.nordicsemi.com/pdf/nRF52_Series_Migration_v1.0.pdf
                   
                  #if __CORTEX_M == 0x04
                  #define NRF5_RESET_EVENT(event)                                                 \
                          event = 0;                                                                   \
                          (void)event
                  #else
                  #define NRF5_RESET_EVENT(event) event = 0
                  #endif
                  
                  
                  // This must be in one line
                  extern "C" { void RADIO_IRQHandler(void) {packetCounter++; NRF5_RESET_EVENT(NRF_RADIO->EVENTS_END); NRF_RADIO->EVENTS_END=0; }}
                  
                  
                  

                  The PPI does toggle an LED each time it receives a packet, but unfortunately the CPU remains asleep. Nonetheless, it does seem to follow your prescription for the ISR.

                  d00616D Offline
                  d00616D Offline
                  d00616
                  Contest Winner
                  wrote on last edited by
                  #929

                  @NeverDie said in nRF5 Bluetooth action!:

                  @d00616
                  Can you see any reason as to why the radio isn't waking the MCU after it receives a packet? Here's the entire sketch:

                  I have no Idea why. The code is looking fine.

                  1 Reply Last reply
                  1
                  • NeverDieN Offline
                    NeverDieN Offline
                    NeverDie
                    Hero Member
                    wrote on last edited by NeverDie
                    #930

                    FWIW, I noticed on the oscilliscope that turning on-and-off the HFCLK ten times a second produces a fair amount of ringing. If I simply leave HFCLK turned on, most of the ringing is eliminated.

                    [Edit: So, if doing this as part of an aggressive energy saving approach (for instance, turning OFF HFCLK after RX mode and later turning it on again before initiating a new RX), what sort of extra circuitry beyond the two inductors for the DCDC might be needed? I don't know that the ringing is causing any actual problems, but it doesn't look proper on a scope. For now, I'm just flagging it so that folks are aware of it as a possible issue. ]

                    NeverDieN 1 Reply Last reply
                    1
                    • NeverDieN NeverDie

                      FWIW, I noticed on the oscilliscope that turning on-and-off the HFCLK ten times a second produces a fair amount of ringing. If I simply leave HFCLK turned on, most of the ringing is eliminated.

                      [Edit: So, if doing this as part of an aggressive energy saving approach (for instance, turning OFF HFCLK after RX mode and later turning it on again before initiating a new RX), what sort of extra circuitry beyond the two inductors for the DCDC might be needed? I don't know that the ringing is causing any actual problems, but it doesn't look proper on a scope. For now, I'm just flagging it so that folks are aware of it as a possible issue. ]

                      NeverDieN Offline
                      NeverDieN Offline
                      NeverDie
                      Hero Member
                      wrote on last edited by NeverDie
                      #931

                      To better quantify the issue, I measured sleep currents (now using sleep routines that are a fork from what's in mysensors.h), and with the High Frequency clock turned OFF, the sleep current is measured at 2.2ua using a uCurrent Gold. However, the same setup, but with the High Frequency clock left ON, the sleep current is measured at 596ua using the same a uCurrent Gold.

                      So, clearly, for a battery/supercap application, leaving the High Frequency clock running all the time is not an especially good option.

                      rmtuckerR 1 Reply Last reply
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                      • NeverDieN NeverDie

                        To better quantify the issue, I measured sleep currents (now using sleep routines that are a fork from what's in mysensors.h), and with the High Frequency clock turned OFF, the sleep current is measured at 2.2ua using a uCurrent Gold. However, the same setup, but with the High Frequency clock left ON, the sleep current is measured at 596ua using the same a uCurrent Gold.

                        So, clearly, for a battery/supercap application, leaving the High Frequency clock running all the time is not an especially good option.

                        rmtuckerR Offline
                        rmtuckerR Offline
                        rmtucker
                        wrote on last edited by
                        #932

                        @NeverDie
                        I am puzzled with your 596ua?
                        I thought you were under 10ua with the mysensors sleep some time ago?
                        Mine only measures 4-5ua when in sleep?

                        NeverDieN 1 Reply Last reply
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                        • NeverDieN NeverDie

                          However, there's one fly in the ointment remaining. It turns out that some other timer is sometimes waking up the CPU:

                          time=15798, Radio STATE=0, COUNTER=0x49, packetCounter=22
                          time=15900, Radio STATE=0, COUNTER=0x49, packetCounter=23
                          time=16001, Radio STATE=0, COUNTER=0x49, packetCounter=24
                          time=16103, Radio STATE=0, COUNTER=0x49, packetCounter=25
                          time=16204, Radio STATE=0, COUNTER=0x49, packetCounter=26
                          time=16306, Radio STATE=0, COUNTER=0x49, packetCounter=27
                          time=512000, Radio STATE=0, COUNTER=0x2035, packetCounter=27
                          time=1024000, Radio STATE=0, COUNTER=0x269, packetCounter=27
                          time=1536000, Radio STATE=0, COUNTER=0x1803, packetCounter=27
                          time=2048000, Radio STATE=3, COUNTER=0x36, packetCounter=27
                          time=2560000, Radio STATE=0, COUNTER=0x1570, packetCounter=27
                          time=3072000, Radio STATE=0, COUNTER=0x3104, packetCounter=27
                          time=3584000, Radio STATE=0, COUNTER=0x1337, packetCounter=27
                          time=4096000, Radio STATE=0, COUNTER=0x2871, packetCounter=27
                          time=4608000, Radio STATE=0, COUNTER=0x1104, packetCounter=27
                          time=5120000, Radio STATE=0, COUNTER=0x2638, packetCounter=27
                          

                          All the lines labelled packetCounter=27 (after the first one that is) are a result of this. Looking at the time, they appear to happen on the rollover of some other timer (?)--apparently the one that is responsible for keeping track of millis(). I can filter them out after-the-fact, but I'd rather they not be waking up the CPU for no reason, as that is just a waste of energy.

                          NeverDieN Offline
                          NeverDieN Offline
                          NeverDie
                          Hero Member
                          wrote on last edited by
                          #933
                          This post is deleted!
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                          • rmtuckerR rmtucker

                            @NeverDie
                            I am puzzled with your 596ua?
                            I thought you were under 10ua with the mysensors sleep some time ago?
                            Mine only measures 4-5ua when in sleep?

                            NeverDieN Offline
                            NeverDieN Offline
                            NeverDie
                            Hero Member
                            wrote on last edited by
                            #934

                            @rmtucker said in nRF5 Bluetooth action!:

                            I am puzzled with your 596ua?
                            I thought you were under 10ua with the mysensors sleep some time ago?

                            There's no contradiction. It's a different scenario. The MySensors hwSleep function turns off the High Frequency oscillator when sleeping and turns it back on when it wakes up. So, it's perfectly fine for sleeping your device, having it wake up to send something, and then go back to sleep.

                            The present scenario that I'm working on though is where the MCU sleeps and the PPI manages a "listen mode" where the PPI wakes up the radio once every 100ms for a roughly 200us window of time to listen for an incoming packet. Then it goes back to sleep if nothing is received. On the other hand, if a packet is received, it wakes up the MCU so that the packet can be read and dealt with. Presently I have the PPI turn off the high-frequency oscillator each time after it has finished RX in the listen-mode cycle. Before entering RX again to listen for a new packet, it first ramps up the high frequency oscillator. According to the datasheet, the high frequency crystal oscillator must be operating in order for the radio to either transmit or receive. i.e. it can't simply run off the high frequency RC oscillator the way the MCU can.

                            My measurements show that while the High Frequency oscillator is running, it consumes about 596ua.

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                            • M Offline
                              M Offline
                              Mike_Lemo
                              wrote on last edited by
                              #935

                              Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?

                              Also why does I2C initializes only after an SWD programmed gets connected?

                              Wierd phenomenon when I use an I2C oled display with that chip and program it with an st link V2 after it displays alright when it's booted if the SWD programmer is connected but as soon as you disconnect it everything else works but the I2C display...

                              NeverDieN U 2 Replies Last reply
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                              • M Mike_Lemo

                                Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?

                                Also why does I2C initializes only after an SWD programmed gets connected?

                                Wierd phenomenon when I use an I2C oled display with that chip and program it with an st link V2 after it displays alright when it's booted if the SWD programmer is connected but as soon as you disconnect it everything else works but the I2C display...

                                NeverDieN Offline
                                NeverDieN Offline
                                NeverDie
                                Hero Member
                                wrote on last edited by NeverDie
                                #936

                                @Mike_Lemo said in nRF5 Bluetooth action!:

                                Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?

                                Yes. @d00616's demo code will do this.

                                I don't know the answers to the rest of your questions, because I don't use the ST.

                                M 1 Reply Last reply
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                                • NeverDieN Offline
                                  NeverDieN Offline
                                  NeverDie
                                  Hero Member
                                  wrote on last edited by NeverDie
                                  #937

                                  Here's a scopeshot of how the revised current draw looks:
                                  0_1506116792416_NewFile7.png
                                  As you can see, there is now about a 370us warm-up time at the beginning for the High Frequency oscillator to come up to speed before the RX cycle can be started. Then it takes about 100us for the receiver to warm-up to RXIDLE. From there it finally achieves about 200us of actual productive RX time. Then everything powers down until the end of the 100ms cycle, after which it all repeats again. To conserve energy, all this is managed by the PPI while the MCU sleeps.
                                  Scale: 1mv=1ma

                                  I think this is about as energy efficient as it's ever going to get, short of chipping away at the number of bits in the frame/packet size, as I indicated earlier.

                                  NeverDieN 2 Replies Last reply
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                                  • NeverDieN NeverDie

                                    @Mike_Lemo said in nRF5 Bluetooth action!:

                                    Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?

                                    Yes. @d00616's demo code will do this.

                                    I don't know the answers to the rest of your questions, because I don't use the ST.

                                    M Offline
                                    M Offline
                                    Mike_Lemo
                                    wrote on last edited by Mike_Lemo
                                    #938

                                    @NeverDie said in nRF5 Bluetooth action!:

                                    @Mike_Lemo said in nRF5 Bluetooth action!:

                                    Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?
                                    

                                    Yes. @d00616's demo code will do this.

                                    I don't know the answers to the rest of your questions, because I don't use the ST.

                                    Any idea how I reach to this code?

                                    Also you say you don't experience any issues with I2C like that?

                                    NeverDieN 1 Reply Last reply
                                    0
                                    • M Mike_Lemo

                                      @NeverDie said in nRF5 Bluetooth action!:

                                      @Mike_Lemo said in nRF5 Bluetooth action!:

                                      Did anyone managed to get two NRF52832 to connect to each other with the arduino IDE and communicate?
                                      

                                      Yes. @d00616's demo code will do this.

                                      I don't know the answers to the rest of your questions, because I don't use the ST.

                                      Any idea how I reach to this code?

                                      Also you say you don't experience any issues with I2C like that?

                                      NeverDieN Offline
                                      NeverDieN Offline
                                      NeverDie
                                      Hero Member
                                      wrote on last edited by NeverDie
                                      #939

                                      @Mike_Lemo said in nRF5 Bluetooth action!:

                                      Any idea how I reach to this code?

                                      Yes, it's all explained in detail by @d00616 here: https://www.openhardware.io/view/376/MySensors-NRF5-Platform

                                      Also you say you don't experience any issues with I2C like that?

                                      Haven't tried I2C on this platform yet. I'd be very surprised if it didn't work though, as that's ARM Cortex M4 stuff, which is well vetted. i.e. no real dependency on anything Nordic per se.

                                      M 1 Reply Last reply
                                      0
                                      • NeverDieN NeverDie

                                        @Mike_Lemo said in nRF5 Bluetooth action!:

                                        Any idea how I reach to this code?

                                        Yes, it's all explained in detail by @d00616 here: https://www.openhardware.io/view/376/MySensors-NRF5-Platform

                                        Also you say you don't experience any issues with I2C like that?

                                        Haven't tried I2C on this platform yet. I'd be very surprised if it didn't work though, as that's ARM Cortex M4 stuff, which is well vetted. i.e. no real dependency on anything Nordic per se.

                                        M Offline
                                        M Offline
                                        Mike_Lemo
                                        wrote on last edited by
                                        #940

                                        @NeverDie said in nRF5 Bluetooth action!:

                                        @Mike_Lemo said in nRF5 Bluetooth action!:

                                        Any idea how I reach to this code?

                                        Yes, it's all explained in detail by @d00616 here: https://www.openhardware.io/view/376/MySensors-NRF5-Platform

                                        Also you say you don't experience any issues with I2C like that?

                                        Haven't tried I2C on this platform yet. I'd be very surprised if it didn't work though, as that's ARM Cortex M4 stuff, which is well vetted. i.e. no real dependency on anything Nordic per se.

                                        The link you attached links me to a getting started page not wireing two nrf's together

                                        NeverDieN M 2 Replies Last reply
                                        0
                                        • M Mike_Lemo

                                          @NeverDie said in nRF5 Bluetooth action!:

                                          @Mike_Lemo said in nRF5 Bluetooth action!:

                                          Any idea how I reach to this code?

                                          Yes, it's all explained in detail by @d00616 here: https://www.openhardware.io/view/376/MySensors-NRF5-Platform

                                          Also you say you don't experience any issues with I2C like that?

                                          Haven't tried I2C on this platform yet. I'd be very surprised if it didn't work though, as that's ARM Cortex M4 stuff, which is well vetted. i.e. no real dependency on anything Nordic per se.

                                          The link you attached links me to a getting started page not wireing two nrf's together

                                          NeverDieN Offline
                                          NeverDieN Offline
                                          NeverDie
                                          Hero Member
                                          wrote on last edited by NeverDie
                                          #941

                                          @Mike_Lemo said in nRF5 Bluetooth action!:

                                          The link you attached links me to a getting started page not wireing two nrf's together

                                          Your question was ambiguous. When you said "connect" I just assumed you meant wirelessly connect.

                                          Sorry, I can't help you. Seems like @scalz has gotten I2C to work with it though, but more likely for reading a TH sensor than for the purpose of wiring two nRF52832's. Still, that would prove that it works. If you know the I2C protocol, it shouldn't be hard to go from that to wiring two nRF52832's together.

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