RAK11310 digital input read issues

[SamSkjord (Sam Conway)]

Hi, I’m trying to read the state of two relays using a RAK11310 mounted to a RAK19010 without success.

I’ve been using the sketch below to troubleshoot,
The relays are connected between pins IO1\IO2 and ground but always return a state of 0, I added the analog input to further troubleshoot and that always returns 1, this happens even if I set the digitalWrites to LOW.

void setup() {
  time_t timeout = millis();
  Serial.begin(115200);
  while (!Serial) {
    if ((millis() - timeout) < 5000) {
      delay(100);
    } else {
      break;
    }
  }
  Serial.println("hi");

  pinMode(WB_A0, INPUT);
  pinMode(WB_IO1, INPUT);
  pinMode(WB_IO2, INPUT);

  digitalWrite(WB_A0, HIGH);
  digitalWrite(WB_IO1, HIGH);
  digitalWrite(WB_IO2, HIGH);
}

void loop() {
  int WB_A0State = digitalRead(WB_A0);
  int WB_IO1State = digitalRead(WB_IO1);
  int WB_IO2State = digitalRead(WB_IO2);

  Serial.println(WB_A0State);
  Serial.println(WB_IO1State); 
  Serial.println(WB_IO2State);
  Serial.println(" ");
  
  delay(1);
}

Any pointers would be greatly appreciated, Thanks.

[carlrowan]

Welcome to RAK forum @SamSkjord ,

The title you put is RAK13003 but I do not see it in your message. It seems you are using RAK11310 IO pins. Can you confirm?

Regarding your question.

Can you share the circuit/schematic? Do you have any pullup resistor on the input pins?

[SamSkjord (Sam Conway)]

Hi Carl, you’re correct! updated the title.

Rough sketch below, I haven’t added any pullups as I believed

digitalWrite(WB_IO1, HIGH);

did this internally?

[carlrowan]

Hi @SamSkjord ,

I haven’t looked deeper on RP2040 and Arduino Mbed port but you can try to enable an internal pullup using this pinMode(WB_A0, INPUT_PULLUP);

If this doesn’t work, you will need an external pull up so that the pins are not left floating.

[SamSkjord (Sam Conway)]

That works perfectly now, thanks for your help

[Mathias434 (Mathias)]

Refer to the RAK11310 documentation to ensure that you are using the correct methods for reading digital inputs. Sometimes, specific modules may have unique requirements.