SPDT toggle switch register only once

Projects General Guidance
18

I should probably just have used a self-centering switch and omitted the feature of it staying in top/bottom.

Lots of options to get what you want. Many types of SPDT or even SPST switches could do the job. Lots of options in code too ... logic, state-change, debouncing, or using 1 or 2 inputs.

Since you already have many unused inputs, the 2-input option is a good choice. Take a look at this for a simple RS latch solution (no debouncing required). Just need to add state-change detection in your code.

Here's a crude example to show the 5 possible states of your switch (tested) ...

// toggle switch
bool up;
bool dn;
bool previousUp;
bool previousDn;

void setup() {
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(15, INPUT_PULLUP);
  pinMode(14, INPUT_PULLUP);
}

void loop() {

  // update previous status
  previousUp = up;
  previousDn = dn;

  // get current status
  up = digitalRead(15);
  dn = digitalRead(14);

  // now test for the logic conditions

  // switch is down
  if (up && !dn) {
    // code here runs continuously while switch is up
    // LED is bright
    digitalWrite(LED_BUILTIN, HIGH);
  }

  // switch is up
  if (dn && !up) {
    // code here runs continuously while switch is down
    // LED is dim
    digitalWrite(LED_BUILTIN, HIGH);
    delay(1);
    digitalWrite(LED_BUILTIN, LOW);
    delay(20);
  }

  // switch is transferring either way
  if (up && dn) {
    // code here runs while switch is transferring from state to state
    // LED blinks quickly 3 times
    digitalWrite(LED_BUILTIN, HIGH);
    delay(5);
    digitalWrite(LED_BUILTIN, LOW);
    delay(50);
    digitalWrite(LED_BUILTIN, HIGH);
    delay(5);
    digitalWrite(LED_BUILTIN, LOW);
    delay(50);
    digitalWrite(LED_BUILTIN, HIGH);
    delay(5);
    digitalWrite(LED_BUILTIN, LOW);
  }

  // switch just went up
  if (dn && !up && previousUp) {
    // code here runs only once
    // LED blinks slowly once
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
  }

  // switch just went down
  if (up && !dn && previousDn) {
    // code here runs only once
    // LED blinks slowly twice
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
  }
}