GPIO Pin interrupt example code

[scottlbaker]

Hi,

I've been trying to get GPIO interrupts to work. I have tried both the Arduino style code: attachInterrupt(digitalPinToInterrupt(ROTA), readEncoder, RISING); and also the SDK call: gpio_set_irq_enabled_with_callback(ROTA, 0x0c, 1, &readEncoder); and neither of these seems to work. My ISR never gets called. Can anyone point me to some example working GPIO interrupt code.

Thanks,
Scott

[scottlbaker]

Here is my current code. It does not work and it seems that the ISR is not getting called.

Thanks,
Scott

// ============================================================================
// encoder :: rotary encoder interrupt test
//
// Arduino IDE settings:
// board: Raspberry Pi Pico (Arduino-Pico)
// programmer: none
//
// ============================================================================

#define TXD1 8 // GPIO8 PIN11 UART1 Tx
#define RXD1 9 // GPIO9 PIN12 UART1 Rx
#define ROTA 6 // GPIO6 PIN8 rotary encoder A
#define ROTB 7 // GPIO7 PIN9 rotary encoder B
#define DIAG 25 // GPIO25 PIN37 Diagnotic LED

#define GPIO 0x0d // GPIO interrupt number
#define CHANGE 0x0c // pos or neg edge triggered

int8_t encoder_val = 0;
uint8_t encoder_state;

// rotary encoder pin change interrupt handler
void readEncoder(uint gpio, uint32_t events) {
encoder_state = (encoder_state << 4) | (digitalRead(ROTB) << 1) | digitalRead(ROTA);
switch (encoder_state) {
case 0x23: encoder_val++; break;
case 0x32: encoder_val--; break;
default: break;
}
irq_clear(GPIO);
}

// rotary encoder init
void encoder_init() {
gpio_set_irq_enabled_with_callback(ROTA, CHANGE, 1, &readEncoder);
encoder_state = (digitalRead(ROTB) << 1) | digitalRead(ROTA);
interrupts();
}

// startup initialization
void setup() {
digitalWrite(DIAG, LOW); // Diag LED is off
pinMode(DIAG, OUTPUT);
pinMode(ROTA, INPUT_PULLUP);
pinMode(ROTB, INPUT_PULLUP);
#define BAUD 115200
Serial2.setRX(RXD1);
Serial2.setTX(TXD1);
Serial2.begin(BAUD);
irq_set_enabled(GPIO, 1);
}

// main program loop
void loop() {
if (encoder_val) {
Serial2.println(encoder_val);
}
delay(10);
}

[earlephilhower]

I suggest using the Arduino-way and not the SDK-way. See #651 where a bug was found and fixed in the Pico SDK (many releases ago) for an example

[scottlbaker]

Hi,

Thanks for the response.
I rolled it back to use the Arduino way and it still doesn't work.
The LED never turns on, so the ISR is never getting called.

Scott

// ============================================================================
// rotary encoder interrupt test
// ============================================================================

#define TXD1 8 // GPIO8 PIN11 UART1 Tx
#define RXD1 9 // GPIO9 PIN12 UART1 Rx
#define ROTA 6 // GPIO6 PIN8 rotary encoder A
#define ROTB 7 // GPIO7 PIN9 rotary encoder B
#define DIAG 25 // GPIO25 PIN37 diagnostic LED

int8_t encoder_val = 0;
uint8_t encoder_state;

// rotary encoder pin change interrupt handler
void readEncoder() {
digitalWrite(DIAG, HIGH); // diag LED is on
encoder_state = (encoder_state << 4) | (digitalRead(ROTB) << 1) | digitalRead(ROTA);
switch (encoder_state) {
case 0x23: encoder_val++; break;
case 0x32: encoder_val--; break;
default: break;
}
}

// rotary encoder init
void encoder_init() {
attachInterrupt(digitalPinToInterrupt(ROTA), readEncoder, RISING);
encoder_state = (digitalRead(ROTB) << 1) | digitalRead(ROTA);
}

// startup initialization
void setup() {
digitalWrite(DIAG, LOW); // diag LED is off
pinMode(DIAG, OUTPUT);
pinMode(ROTA, INPUT_PULLUP);
pinMode(ROTB, INPUT_PULLUP);
#define BAUD 115200
Serial2.setRX(RXD1);
Serial2.setTX(TXD1);
Serial2.begin(BAUD);
delay(100);
}

// main program loop
void loop() {
if (encoder_val) {
Serial2.println(encoder_val);
}
delay(10);
}

[scottlbaker]

Oops .. 1000 apologies .. typo on my part .. working now ..

Thanks !!
Scott

[earlephilhower]

Great, glad to hear it's working!