@tlustoch
The node is a very simple one. So I never considered boot loaders, as the node would not need changing sketches during it's lifetime. I have boot loading functionality on my other designs, this one is a minimal board. Any extra chip would beat the purpose of the word "minimal".
It's a dumb node for a reason
I have success!
(oops, that's suppose to be Timer1)
I only sample for 1/60 of a second. What I did was to back up all the timer registered I used and then resorted them after I was done sampling. (As opposed to initializing the registers in setup and then starting the timer when needed.)
Now I have a Nano sampling the data and sending it to a MySensors Gateway on an RPi3B+ which then sends it to an MQTT broker runing on an old laptop. Also running on the laptop is Home Assistant running inside of VirtualBox.
If MySensors does use Timer1, it appears that restoring the registers allows it to be shared.
//------------------------------------------------------ISR
ISR(TIMER1_OVF_vect){ // interrupt service routine for overflow
TCNT1 = TimerPreloadValue; // must be first line! starts the timer counting again
digitalWrite(TRIGGER_START_SAMPLE_PIN,HIGH);
samplesVolts[--sample]=analogRead(VOLTS_IN_PIN); // decrement before capturing
samplesCurrent[sample]=analogRead(CURRENT_IN_PIN);
digitalWrite(TRIGGER_START_SAMPLE_PIN,LOW);
if (!sample){ // count down to zero
digitalWrite(TRIGGER_START_SAMPLE_PERIOD_PIN,LOW); // indicate that sampling is complete
samplingEnd = micros();
TCCR1B &= 248; // turns off timer
}
}
//------------------------------------------------------sampleOneCycle
void sampleOneCycle(){
// back up timer registers
uint8_t TCNT1_b = TCNT1;
uint8_t TCCR1B_b = TCCR1B;
uint8_t TCCR1A_b = TCCR1A;
uint8_t TIMSK1_b = TIMSK1;
// configure timer which starts the sampling
noInterrupts(); // disable all interrupts
TCCR1A = 0;
TCCR1B = 0;
TCNT1 = TimerPreloadValue; // preload timer
//TCCR1B |= (1 << CS10)|(1 << CS12); // 1024 prescaler
TCCR1B &= 248; // turns off timer?
TIMSK1 |= (1 << TOIE1); // enable timer overflow interrupt ISR
// demark sampling
sample = NUMBER_OF_SAMPLES; // count down to zero
digitalWrite(TRIGGER_START_SAMPLE_PERIOD_PIN,HIGH);
samplingStart = micros();
TCNT1 = 65535; // first trigger right away!
TCCR1B |= 1; // turns on timer
interrupts(); // enable all interrupts
// wait for sampling to be complete
while(digitalRead(TRIGGER_START_SAMPLE_PERIOD_PIN)){};
samplingEnd = micros();
// restore timer registers
TCNT1 = TCNT1_b;
TCCR1B = TCCR1B_b;
TCCR1A = TCCR1A_b;
TIMSK1 = TIMSK1_b;
}
Very useful topic for me, thanks. Even though it's been a long time, the information was useful to me. And especially the information on the link you sent.
@WiktorDIY The ch340 are notorious for being broken. The best I ever achieved was 19200 and flakey..
I purchased a real Nano not a ch knock off eg uses a different uart no problems
@fets So far, I have only built the 5x5 board (but the others should be schematically identical). The only issue I have found so far is that I cannot get the ISP port to work. But I have checked and I have an identical setup on the 1.0 board and that worked, so I suspect the programmer is too weak to drive the net on this one. So it is not a board-issue per se, and might only be an issue on the 5x5 board as routing is the most complex on that one due to the size.
