Grove Earclip Heart Rate Sensor with Sparks

Troubleshooting
1

Hi,

I tried to to convert Grove Ear clip Heart Rate Sensor to Sparks and I am having problem getting the signal from the Ear clip sensor to my Spark Core. Any advise ?

I test the sensor on Arduino and it’s working fine with 5 V in to the Ear Clip sensor and Sensor O/P to D2 to Arduino.

2

If you used the demo sketch from here problem lies in this line

	attachInterrupt(0, interrupt, RISING);//set interrupt 0,digital port 2

You’d need to change the 0 for D2, but I’d go for a 5V tolerant pin (D0, D1, D3, D4, D5, D6 and D7), if you’ve got your sensor powerd off 5V.
I would also keep the interrupt service routine shorter.

If you’ve got your own code, we’d need to see it

1 Like
3

Yes. I did change the ‘0’ to D1 and used D1 to trigger the ISR routine. And I used Vin to power the Grove Sensor.

void setup()
{
  //.....
  earclipInit();
  attachInterrupt(D1, earclipISR, RISING);//set interrupt 0,digital port 1
}

void earclipISR()
{
  noInterrupts();

  times[counter] = millis();
  heartState = !heartState;

  if (counter == 0)
  {
    sub = times[counter] - times[20];
  }
  else
  {
    sub = times[counter] - times[counter-1];
  }
  Serial.println(sub);


  // if no response after max duty cycle reset counter
  if (sub > maxHeartPulseDuty)
  {
      counter = 0;
      data_effect = false;
      Serial.println("Heart Rate Measure Error !, Restart Test");
      earclipInit();
  }

  if (counter == 20 && data_effect)
  {
    counter = 0;
    sum();
  }
  else if (counter<20 && data_effect )
  {
    counter++;
  }
  else
  {
    counter = 0;
    data_effect = true;
  }

  interrupts();
}

I used a wire connected to 3V3 and touches the D1 and the ISR is called.

So, will level shifter help ?

4

Yes. Level Shifter did help. The other thing is i need to set D1 as INPUT.

i.e. pinMode(D1, INPUT);

1 Like