I'm using and ESP-32CAM and a reed switch triggers an interrupt on GPIO2 but not on GPIO4, any idea why?

FBMinis
Posts: 15
Joined: Sun Jan 17, 2021 1:08 pm

I'm using and ESP-32CAM and a reed switch triggers an interrupt on GPIO2 but not on GPIO4, any idea why?

Postby FBMinis » Tue Oct 24, 2023 5:06 pm

I'm programming this AI-Thinker ESP-32CAM in the Arduino IDE. Im not using any of the camera functions right now. The code below is what I have running.

Passing a magnet by the reed switch increases the counter. Trying the same code on pin 4 (GPIO4) doesnt produce any result.

Code: Select all

static void IRAM_ATTR reedswitch_ISR(void* arg);

int reedswitchpin = 2;
uint32_t numberToggles;
volatile bool toggled = false;
unsigned long reed_time = 0;
unsigned long last_reed_time = 0;

static void setupinterrupts() {
  pinMode(reedswitchpin, INPUT_PULLUP);

  // Install the GPIO ISR service
  gpio_install_isr_service(0); // You can use a different number (0, 1, 2) if needed

  esp_err_t err = gpio_isr_handler_add((gpio_num_t)reedswitchpin, &reedswitch_ISR, (void*) NULL);

  if (err != ESP_OK) {
    Serial.printf("gpio_isr_handler_add failed (%x)", err);
  }
  gpio_set_intr_type((gpio_num_t)reedswitchpin, GPIO_INTR_NEGEDGE);
}

static void IRAM_ATTR reedswitch_ISR(void* arg) {
  reed_time = millis();

  if (reed_time - last_reed_time > 250) {
    numberToggles++;
    toggled = true;
    last_reed_time = reed_time;
  }
}

void setup() {
  Serial.begin(115200);
  delay(100);
  setupinterrupts();
  delay(100);
  Serial.println("waiting...");
}

void loop() {
  if (toggled) {
    Serial.printf("reed has been toggled %u times\n", numberToggles);
    Serial.println(" ");
  }
  toggled = false;
}

FBMinis
Posts: 15
Joined: Sun Jan 17, 2021 1:08 pm

Re: I'm using and ESP-32CAM and a reed switch triggers an interrupt on GPIO2 but not on GPIO4, any idea why?

Postby FBMinis » Wed Oct 25, 2023 10:37 am

I have learned that GPIO4 is connected to the onboard "flash" LED of the AI Thinker ESP32CAM.

I was able to setup interrupts on GPIO16 and GPIO02 that behave correctly.

Is there a way to setup and interrupt on GPIO04 if I dont plan on using he sdcard nor the flash led?

PepeTheGreat
Posts: 20
Joined: Mon Sep 18, 2023 3:54 am

Re: I'm using and ESP-32CAM and a reed switch triggers an interrupt on GPIO2 but not on GPIO4, any idea why?

Postby PepeTheGreat » Wed Oct 25, 2023 6:31 pm

GPIO4 is alredy used for flash LED?
I do use gpio 12,13,15,14,2 and they all work.
If you want use gpio4 disable "ledcAttachPin(4, 7); //pin4 is LED"

FBMinis
Posts: 15
Joined: Sun Jan 17, 2021 1:08 pm

Re: I'm using and ESP-32CAM and a reed switch triggers an interrupt on GPIO2 but not on GPIO4, any idea why?

Postby FBMinis » Wed Oct 25, 2023 6:49 pm

Thank you. It seems that removing R13 also disables the LED circuit, allowing to use GPIO4 as long as SDCards is not being used.

Who is online

Users browsing this forum: danpf1 and 39 guests