Problems with interrupts on nano 33 ble.

Official Hardware Nano Family Nano 33 BLE
1

Hi,

A simple code that works fine on the old arduino nano is not working on the nano 33 ble. It seems to be a kind of problem with the interrupt pins.

I'm working with the pololu magnetic encoder attached to the digital 2 and 3 pins.

Anyone could help?

#define ENCESQ 2
#define ENCDIR 3

long PULSOESQ = 0;
long PULSODIR = 0;

void encoderesq()
{
PULSOESQ++;
Serial.println(PULSOESQ);
}

void encoderdir()
{
PULSODIR++;
Serial.println(PULSODIR);
}

void setup() {
Serial.begin(9600);
pinMode(ENCESQ, INPUT_PULLUP);

digitalWrite(ENCESQ, HIGH); //turn pullup resistor on

attachInterrupt(digitalPinToInterrupt(ENCESQ), encoderesq, CHANGE);
attachInterrupt(digitalPinToInterrupt(ENCDIR), encoderdir, CHANGE);

}

void loop() {

}

2

I guess mbedOS does not like you to use the Serial.print in the ISRs. Its a bad idea anyways, ISR should be as short as possible, especially with an OS. Try this.

#define ENCESQ 2
#define ENCDIR 3

long PULSOESQ = 0;
long PULSODIR = 0;

void encoderesq()
{
  PULSOESQ++;
}

void encoderdir()
{
  PULSODIR++;
}

void setup()
{
  Serial.begin( 9600 );
  while ( !Serial );
  Serial.println( "Pin Interrupt Demo" );

  pinMode( ENCESQ, INPUT_PULLUP );
  pinMode( ENCDIR, INPUT_PULLUP );

  //digitalWrite(ENCESQ, HIGH); //turn pullup resistor on

  attachInterrupt( digitalPinToInterrupt( ENCESQ ), encoderesq, CHANGE );
  attachInterrupt( digitalPinToInterrupt( ENCDIR ), encoderdir, CHANGE );

}

void loop()
{

  Serial.print( "PULSOESQ: " );
  Serial.println( PULSOESQ );

  Serial.print( "PULSODIR: " );
  Serial.println( PULSODIR );

  delay( 1000 );
}

Additionally, I do not think you need to do the digitalWrite to enable the pull ups. I just used a button module I have that has a pull up on board. So, you need to test this with your setup.

3

you are the man!

It works!

Thank you.