ESP8266 Community Forum

- Tue Nov 01, 2016 6:26 pm #57518 I'm polling pin D4 frequently and I think its causing:

Soft WDT reset
ctx: cont

Its for a POV set up and I'm trying to calculate the speed of rotation so I can set a variable delay to adjust the speed of the LED fill routine.
I have a couple of delay(0); statements which solved my previous WDT crashes but when I introduced the polling it started happening again.
Working out roughly in my head I could be polling the pin roughly twice a ms in an extreme case. Is this too much? Perhaps I should use an interrupt but I was worried about problems with the wifi.

I won't post my whole sketch but here is the main loop and the two helper functions it uses. The rest is just variable definitions, wifi and LED set up.

Code: Select allvoid reedSwitch() { //routine when one revolution is detected
  variableDelay = ((millis() - lasttime - CYCLETIME) * 1000) / 176; //calculate variable delay to make one image frame = approximately one revolution
  constrain (variableDelay, 0, 2000); //constrain delay because of worries about watchdog timer!
  butToggle = false; //set toggle for repeated reed switch readings
  goback = true; //set toggle for running the LED routine next time around
}

void sickLED(int vd) {

  lasttime = millis();
  goback = false; //set toggle
  int f = numberOfSlices;
  int z; //a counter

  for (int x = 0; x < f; x++) {
    for (z = 0; z < 48; z++) {
      leds[z + 13] = monroe[(x * 48) + (z)]; //fill led array from a larger array of image data
    }

    FastLED.show(); //send data to pixels
    delay(0); //keep the watchdog timer happy

    if (!digitalRead(pushButton) && butToggle) { //check for reed switch activation. If it is closed set toggles and exit draw routing
      reedSwitch();
      delay(0);
      return;
    } else {
      if (digitalRead(pushButton)) {
        butToggle = true;
      }
    }
    //1500 fan sppeed 1 ~ 4 rps
    //800 fan speed 2 ~ 6 rps
    //565 fan speed 3

    delayMicroseconds(vd); //may need to increase / decrease depending on spin rate
  }


void loop() {
  ArduinoOTA.handle(); //system call

  if (goback) sickLED(variableDelay); //if toggle set, run the routine which sets a frame of LEDS

  if (!digitalRead(pushButton) && butToggle) { //if reed switch newly activated......
    reedSwitch();
  } else {
    if (digitalRead(pushButton)) { //if reed switch is closed
      butToggle = true; //set toggle
      FastLED.clear(); // clear leds
      FastLED.show();
    }
  }
  if ((millis() - lasttime) > 5000) {
    FastLED.clear();
    FastLED.show();
  }
}

}

- Tue Nov 01, 2016 7:43 pm #57522 After a quick go with interrupts I think my issue may have been called by the input pin bouncing.
Maybe this was triggering a bunch of consecutive routine calls which meant I wasn't getting to the delay(0); quick enough.
Not really sure but no crashes for a while!

- Wed Nov 02, 2016 7:49 am #57543 Nope still crashing

- Wed Nov 02, 2016 10:03 am #57552 Apologies to all of you sitting on the edges of your seats waiting to see what will happen with this one!
My current theory is that my misuse of 'constrain' was sometimes causing a huge variable delay which alerted the WDT.
It should be value=constrain(value,low,high);