nRF5 action!

rmtucker

Seems it may have something to do with this in the code.

// Calculate sleep time
		// 8 Hz -> max 582.542 hours sleep.
		MY_HW_RTC->PRESCALER = 4095;
		// Set compare register to 1/125ms + 2 to garantee event triggering
		MY_HW_RTC->CC[0] = (ms / 125) + 2;```

rmtucker

MY_HW_RTC->CC[0] = (ms / 125) + 2;

It seems the +2 above is adding 250ms.
Why is it done like this???

NeverDie

What more can be done to reduce current consumption on an nRF52832 when the MySensors "sleep" function is being used with RTC wakeup. I've measured a 300mv drop on a 10F capacitor over a 12 hour time period. Of that 300mv, perhaps 20mv was lost due to self-discharge of the supercap. So, that still leaves 280mv of loss due to the nRF52832 . That is too high a rate of loss.

rmtucker

@NeverDie
Seeing Your sketch would help?

d00616

@rmtucker said in nRF5 Bluetooth action!:

MY_HW_RTC->CC[0] = (ms / 125) + 2;

It seems the +2 above is adding 250ms.
Why is it done like this???

A minimum of two ticks are required to be sure the CC[0] is triggered.

What accuracy is your requirement? I can add more code here to dynamical change the pre scaler plus a check if ms/125>=2

rmtucker

@d00616
My initial thoughts were how the nrf51822 could be used for energy meters (counting pulses and the gap between them),But unlike the arduino's which can not run timers when in sleep mode,The nrf5 can of course do this.
So the nrf5 would be able to report watts and usage while still using sleep mode.
But seeing the inaccuracy of the timer has put the brakes on that.
Yes being able to change the prescaler dynamically would help a great deal as 125ms / 582.542 hours is not really useful for most applications with a 250ms overrun.

rmtucker

Just wondering what the prescaler etc would have to be set to for ms accuracy and how long before overflow.(aint got my maths head on today):blush:

d00616

@NeverDie said in nRF5 Bluetooth action!:

What more can be done to reduce current consumption on an nRF52832 when the MySensors "sleep" function is being used with RTC wakeup. I've measured a 300mv drop on a 10F capacitor over a 12 hour time period. Of that 300mv, perhaps 20mv was lost due to self-discharge of the supercap. So, that still leaves 280mv of loss due to the nRF52832 . That is too high a rate of loss.

Wh = 0.5 * 10F * 280mV = 0.392 Wh = 0.0326667 W
I=0.0326667/2.56V = 12.76mA

Looks like the node is most time fully active.

d00616

@rmtucker said in nRF5 Bluetooth action!:

@d00616
My initial thoughts were how the nrf51822 could be used for energy meters (counting pulses and the gap between them),But unlike the arduino's which can not run timers when in sleep mode,The nrf5 can of course do this.
So the nrf5 would be able to report watts and usage while still using sleep mode.

If you have the idea to store the results into the EEPROM like storage the nRF5, then read the hints about this: https://github.com/d00616/arduino-NVM/#nvramh

The virtual EEPROM, the radio or debugging output are adding latency to the main loop. You will see more timing errors in long term run when you trust the sleep() time.

The nRF5 can help you to count without adding latency by the cpu. You can use a timer in counter mode which TASK_COUNT and TASKS_CAPTURE[0] are triggered by PPI. Then you can compare the hwMillis() with the last seen CC[0] content and do precise calculation of events.

With nRF52 there is an unused RTC wich can trigger TASKS_CAPTURE[0] at a specific time. One RTC is used for millis() in arduino-nrf5 and one RTC is used for sleep.

But seeing the inaccuracy of the timer has put the brakes on that.
Yes being able to change the prescaler dynamically would help a great deal as 125ms / 582.542 hours is not really useful for most applications with a 250ms overrun.

I will change this.

NeverDie

@rmtucker
Here it is, though it's rather messy. Nonetheless, all it does is measure the supercap and solar panel voltages, send them, then sleep for 12 hours. Then repeats:

// nrf51_client.pde
// -*- mode: C++ -*-
// Example sketch showing how to create a simple messageing client
// with the RH_NRF51 class. RH_NRF51 class does not provide for addressing or
// reliability, so you should only use RH_NRF51 if you do not need the higher
// level messaging abilities.
// It is designed to work with the other example nrf51_server.
// Tested on RedBearLabs nRF51822 and BLE Nano kit, built with Arduino 1.6.4.
// See http://redbearlab.com/getting-started-nrf51822/
// for how to set up your Arduino build environment
// Also tested with Sparkfun nRF52832 breakout board, witth Arduino 1.6.13 and
// Sparkfun nRF52 boards manager 0.2.3
#include <RH_NRF51.h>
#include <MySensors.h>


unsigned long SLEEP_TIME = 43200000; // 12 hour sleep time between measurements (in milliseconds)
//unsigned long SLEEP_TIME = 3600000; // 1 hour sleep time between measurements (in milliseconds)
//unsigned long SLEEP_TIME = 300000; // 5 minute sleep time between measurements (in milliseconds)
//unsigned long SLEEP_TIME = 1000; // 1 second sleep time between measurements (in milliseconds)
#define SUPERCAP_PIN A2  //input pin for reading the supercap's voltage
#define SOLAR_PANEL_PIN A4  //input pin for reading the solar panel's voltage
#define LDO_ENABLE_PIN 8  //D8 (P0.19) is output pin for enabling (HIGH) or disabling (LOW) the LDO
#define NUM_MEASUREMENTS_TO_AVERAGE 3  //number of measurements to collect and then average
#define MAX_MEASUREMENTS 10 //Maximum number of voltage measurements before returning a result.

// Singleton instance of the radio driver
RH_NRF51 nrf51;
uint8_t data[10];

uint16_t batteryVoltage() {
  uint16_t lastRawVoltage, newRawVoltage;
  //uint16_t counter=0;
  //lastRawVoltage = hwCPUVoltage();  //throw away the first voltage measurement
  newRawVoltage = hwCPUVoltage();

    
  return newRawVoltage; 
}




uint16_t readRawVoltageOnPin(uint8_t thePin) {
  uint16_t lastRawVoltage, newRawVoltage;
  uint16_t counter=0;
  lastRawVoltage = analogRead(thePin);
  newRawVoltage = analogRead(thePin);
  while (((newRawVoltage != lastRawVoltage)) && (counter<MAX_MEASUREMENTS)) {  //measure until two consecutive measurements match
    lastRawVoltage=newRawVoltage;
    newRawVoltage=analogRead(thePin);
    counter++;
  }
  uint32_t sumOfMeasurements=0;
  for (int i=0;i<NUM_MEASUREMENTS_TO_AVERAGE;i++) {
    sumOfMeasurements=sumOfMeasurements+analogRead(thePin);
  }
    
  return (sumOfMeasurements/NUM_MEASUREMENTS_TO_AVERAGE); 
}

void myBaro()
{

  uint32_t superCapVoltage=0;
  uint32_t solarPanelVoltage=0;
  uint32_t superCapRawVoltage=0;
  uint32_t solarPanelRawVoltage=0;

  digitalWrite(LDO_ENABLE_PIN, LOW);  //disconnect solar panel
  superCapRawVoltage = readRawVoltageOnPin(SUPERCAP_PIN);
  
  superCapVoltage = (3048*(((superCapRawVoltage)*3127)/4095))/1591;
  //Serial.print("SuperCap voltage=");
  //Serial.println(superCapVoltage);

  //send(msg1_S_BARO_P.set(superCapVoltage));  //superCap's raw voltage
//  wait(500);

//  wait(500);
  //delayMicroseconds(1000);  //wait for voltage to adjust after LDO disabled.  Necessary???
  
  solarPanelRawVoltage=readRawVoltageOnPin(SOLAR_PANEL_PIN);
  digitalWrite(LDO_ENABLE_PIN, HIGH);  //re-connect solar panel
  solarPanelVoltage=(5500*(((solarPanelRawVoltage)*3181)/4095))/1289;
  //Serial.print("Solar Panel Voltage=");
  //Serial.println(solarPanelVoltage);
  //superCapVoltage=1234;

  data[0]= (superCapVoltage/1000)+'0';
  data[1]= ((superCapVoltage%1000)/100)+'0';
  data[2]= ((superCapVoltage%100)/10)+'0';
  data[3]= (superCapVoltage%10)+'0';
  data[4]=',';
  data[5]= (solarPanelVoltage/1000)+'0';
  data[6]= ((solarPanelVoltage%1000)/100)+'0';
  data[7]= ((solarPanelVoltage%100)/10)+'0';
  data[8]= (solarPanelVoltage%10)+'0';
  data[9]='\0';
  nrf51.send(data, sizeof(data));
  nrf51.waitPacketSent();
}


void setup() 
{
  pinMode(LDO_ENABLE_PIN, OUTPUT);  // Enable/Disable pin for the LDO
  digitalWrite(LDO_ENABLE_PIN, HIGH);  //enable the LDO.

  analogReadResolution(12);  //use 12-bit ADC resolution
  pinMode(SUPERCAP_PIN,INPUT);  //Supercap voltage measurement pin
  pinMode(SOLAR_PANEL_PIN,INPUT);  //Solar panel voltage measurement pin
  
  //delay(1000); // Wait for serial port etc to be ready
  Serial.begin(250000);
  //while (!Serial) 
    ; // wait for serial port to connect. 
  if (!nrf51.init())
    Serial.println("init failed");
  // Defaults after init are 2.402 GHz (channel 123), 2Mbps, 0dBm
  if (!nrf51.setChannel(123))
    Serial.println("setChannel failed");
  if (!nrf51.setRF(RH_NRF51::DataRate2Mbps, RH_NRF51::TransmitPower4dBm))
    Serial.println("setRF failed"); 
  
  // AES encryption can be enabled by setting the same key in the sender and receiver
//  uint8_t key[] = { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
//                    0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08};
//  nrf51.setEncryptionKey(key);

//  nrf51.printRegisters();
  Serial.println("Setup of nr51 client completed.");
  Serial.println("Sending to nrf51_server...");
  Serial.flush();
}

uint32_t sentCounter=0;
uint32_t replyCounter=0;

void loop()
{
  //uint16_t theBatteryVoltage;
  //theBatteryVoltage=batteryVoltage();
  //theBatteryVoltage=batteryVoltage();
 // Serial.print("Battery voltage = ");
  //Serial.print(theBatteryVoltage);
  //Serial.println(" millivolts.");
  
  // Send a message to nrf51_server
  //uint8_t data[] = "Hello World!";
/*
  data[0]= (theBatteryVoltage/1000)+'0';
  data[1]= ((theBatteryVoltage%1000)/100)+'0';
  data[2]= ((theBatteryVoltage%100)/10)+'0';
  data[3]= (theBatteryVoltage%10)+'0';
  data[4]='\0';
  nrf51.send(data, sizeof(data));
  sentCounter++;
  nrf51.waitPacketSent();

 */
  myBaro();

  /*
  // Now wait for a reply
  uint8_t buf[RH_NRF51_MAX_MESSAGE_LEN];
  uint8_t len = sizeof(buf);

  if (nrf51.waitAvailableTimeout(500))
  { 
    // Should be a reply message for us now   
    if (nrf51.recv(buf, &len))
    {
      Serial.print("got reply: ");
      Serial.println((char*)buf);
      replyCounter++;
    }
    else
    {
      Serial.println("recv failed");
    }
  }
  else
  {
    Serial.println("No reply, is nrf51_server running?");
  }
  Serial.print("sentCounter="); 
  Serial.print(sentCounter);
  Serial.print(", replyCounter=");
  Serial.println(replyCounter);
  Serial.flush();
  */
 
  sleep(SLEEP_TIME); // Sleeps for 12 hours in deep sleep
}

Using Termite to timestamp the output received, what I got was:

2017/08/25 17:04:13: got request: 2684,0085

2017/08/26 05:04:12: got request: 2396,0076

You can ignore the solar panel measurements, because I disconnected it so as to not interfere.

On the bright side, it woke up and reported within 1 second of when it was supposed to, after a 12 hour sleep.

d00616

@NeverDie said in nRF5 Bluetooth action!:

Here it is, though it's rather messy. Nonetheless, all it does is measure the supercap and solar panel voltages, send them, then sleep for 12 hours. Then repeats:

RadioHead sets the radio into the Idle state. The radio isn't powered off. There is no call in RadioHead to power off the radio.

rmtucker

@NeverDie
So your sketch only wakes up every 12hours.
What current is it drawing using the radiohead library vs mysensors for an equivalent 12 hour sleep because in past discussions with you i remember you saying 5-6uA while sleeping,is this still correct?
I dont see much advantage to the radiohead library if only sending at 12hour intervals.

NeverDie

@rmtucker said in nRF5 Bluetooth action!:

@NeverDie
So your sketch only wakes up every 12hours.
What current is it drawing using the radiohead library vs mysensors for an equivalent 12 hour sleep because in past discussions with you i remember you saying 5-6uA while sleeping,is this still correct?
I dont see much advantage to the radiohead library if only sending at 12hour intervals.

The 6ua was measured with it in deep sleep, where it relied on an external interrupt to wakeup. This measurement was intended to see what it would be if it woke-up using the RTC. So, the 12 hour interval is artificial, for measurement purposes.

@d00616
I had wrongly assumed that the "sleep(...)" command would sleep the radio. Thanks for pointing out my error. How/when is it that Mysensors puts the radio to sleep? Does it just happen automatically at the end of every sending/receiving?

d00616

@NeverDie said in nRF5 Bluetooth action!:

I had wrongly assumed that the "sleep(...)" command would sleep the radio. Thanks for pointing out my error. How/when is it that Mysensors puts the radio to sleep? Does it just happen automatically at the end of every sending/receiving?

We are both not 100% correct ;-) The hwSleep() function doesn't disable the radio, but the sleep() function does it, when MY_SENSOR_NETWORK is defined.

After Sleep transportReInitialise() is called. Then you have to initialize RadioHead again.

NeverDie

@d00616 said in nRF5 Bluetooth action!:

After Sleep transportReInitialise() is called. Then you have to initialize RadioHead again.

So, even with RAM retention active while sleeping, each time the radio is awoken, it needs to be re-initialized?

d00616

@NeverDie said in nRF5 Bluetooth action!:

So, even with RAM retention active while sleeping, each time the radio is awoken, it needs to be re-initialized?

The Radio has to be initialized after power down. This doesn't depend on RAM retention.

NeverDie

According to Table 39 of the mRF52832 datasheet, there is only one radio state resembling sleep, and that is the DISABLED radio state where "No operations are going on inside the radio and the power consumption is at a minimum."

Apparently the radio is disabled through register TASKS_DISABLE, offset 0x010, Disable RADIO, as indicated by Table 41 register overview.

NeverDie

But how exactly does one read or write to these registers? It looks like a quite different arrangement than writing to registers for an nRF24 or an RFM69 or a LoRa chip.

d00616

@NeverDie said in nRF5 Bluetooth action!:

But how exactly does one read or write to these registers? It looks like a quite different arrangement than writing to registers for an nRF24 or an RFM69 or a LoRa chip.

You have to include nrf.h. To disable the radio, you can do this:

https://github.com/mysensors/MySensors/blob/development/drivers/NRF5/Radio_ESB.cpp#L264

If your transmitting power is 0dbm, then "TX only run current PRF = 0dBm" with 11.6 mA is near the calculated current, when the radio stays in TX mode after sending the data.

NeverDie

@d00616
Will this block of code guarantee that the radio is disabled?

  Serial.println("Testing whether radio is disabled...");
  Serial.print("NRF_RADIO->EVENTS_DISABLED=");
  Serial.println(NRF_RADIO->EVENTS_DISABLED);
  while (!(NRF_RADIO->EVENTS_DISABLED)) {
    Serial.print("NRF_RADIO->EVENTS_DISABLED=");
    Serial.println(NRF_RADIO->EVENTS_DISABLED);
    NRF_RADIO->TASKS_DISABLE = 1;  //sleep the radio
  }
  Serial.println("Radio disabled.");

nRF5 action!

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