Electron freezes with solid green or cyan LED

Troubleshooting
17

@peekay123, no, I didn’t come to the conclusion of Log.trace calls are causing crash. They’ve been added after the fact and I think they are only pointing to where I think the problem is. I’m not sure what the evidence for Log calls causing crash? I do not have these calls in my normal firmware.

The code below and above is the exact code I am running on my test devices, so there are not other sensors or anything else being read from. In my normal firmware, there are other sensors, like a ds18b20, but nothing that requires pulse counting like this.

Here is a revision with change to Serial.print’s:

#include "application.h"

SYSTEM_MODE(MANUAL);
SYSTEM_THREAD(ENABLED);
STARTUP(System.enableFeature(FEATURE_RETAINED_MEMORY));

#define SENSOR_FAIL 2
#define SENSOR_SUCCESS 3

int dataPin = D3;
int powerPin = C0;
int status;
uint32_t timerStart;
uint32_t timerStop;
uint16_t rpm;
uint32_t delayTimer = 3000;

unsigned long rpmCountFrozen = 0;
volatile unsigned long rpmCount;

void getRpm();
void interrupt();

void setup() {
  Serial.begin(9600);
  pinMode(dataPin, INPUT);
  pinMode(powerPin, OUTPUT);
}

void loop() {
  getRpm();
  Serial.print("RPM: ");
  Serial.print(rpm);
  Serial.print(", millis: ");
  Serial.println(millis());
  delay(1000);
}

void getRpm() {
  digitalWrite(powerPin, LOW);
  delay(50);

  Serial.println("TACH0");
  rpm = 0;

  rpmCount = 0;
  rpmCountFrozen = 0;
  attachInterrupt(dataPin, interrupt, RISING);

  timerStart = millis();

  Serial.println("TACH1");
  while(millis() - timerStart < delayTimer) {
    Particle.process();
  }
  Serial.println("TACH2");

  timerStop = millis();
  rpmCountFrozen = rpmCount;
  Serial.println("TACH3");  
  //Disable interrupt when calculating
  noInterrupts();
  delay(1);
  detachInterrupt(dataPin);
  interrupts();
  Serial.println("TACHDET");
  Serial.flush();
  Serial.println("TACH4");
  Serial.flush();

  rpm = (uint16_t)(rpmCountFrozen / ((timerStop - timerStart) / 1000));
  Serial.println("TACH5");
  Serial.flush();
  
  rpmCount = 0;

  Serial.println("TACH6");
  Serial.flush();
  if(rpm >= 0 && rpm < 5000) {
    status = SENSOR_SUCCESS;
  } else {
    status = SENSOR_FAIL;
    rpm = 0;
  }
  
  digitalWrite(powerPin, HIGH);
  return;
}

void interrupt() {
  rpmCount++;
}