How to get rotary telephone to recognise each number

Other Hardware Audio
1

Hi,

Please can someone help I am trying to get an old rotary phone recognise each number that is dialled.

Please could someone help with a code and/or with what to plug where.

This is what I've tried but its not working...

This is the code I used

int needToPrint = 0;
int count;
int in = 2;
int lastState = LOW;
int trueState = LOW;
long lastStateChangeTime = 0;
int cleared = 0;

// constants

int dialHasFinishedRotatingAfterMs = 100;
int debounceDelay = 10;

void setup()
{
Serial.begin(9600);
pinMode(in, INPUT);
}

void loop()
{
int reading = digitalRead(in);

if ((millis() - lastStateChangeTime) > dialHasFinishedRotatingAfterMs) {
// the dial isn't being dialed, or has just finished being dialed.
if (needToPrint) {
// if it's only just finished being dialed, we need to send the number down the serial
// line and reset the count. We mod the count by 10 because '0' will send 10 pulses.
Serial.print(count % 10, DEC);
needToPrint = 0;
count = 0;
cleared = 0;
}
}

if (reading != lastState) {
lastStateChangeTime = millis();
}
if ((millis() - lastStateChangeTime) > debounceDelay) {
// debounce - this happens once it's stablized
if (reading != trueState) {
// this means that the switch has either just gone from closed->open or vice versa.
trueState = reading;
if (trueState == HIGH) {
// increment the count of pulses if it's gone high.
count++;
needToPrint = 1; // we'll need to print this number (once the dial has finished rotating)
}
}
}
lastState = reading;
}

errrorrrr.jpg
errrorrrr.jpg4032×3024 714 KB

2

Schematic? Is the phone working as-wired? Are you getting anything when you dial?

i.e. Run the Digital Read Serial Example to see if the phone is doing anything?

3

Please edit your posting to put the code in code tags ( the </> icon ) so we can read it please...

4

I guess it should be wired like this if the dial contact is normally closed. You could alternatively use an internal pull up resistor instead of the external 10K resistor if the assumptions here are correct.

Dial.JPG

You should have auto-formatted and posted your code like this:

int needToPrint = 0;
int count;
int in = 2;
int lastState = LOW;
int trueState = LOW;
long lastStateChangeTime = 0;
int cleared = 0;

// constants

int dialHasFinishedRotatingAfterMs = 100;
int debounceDelay = 10;

void setup()
{
  Serial.begin(9600);
  pinMode(in, INPUT);
}

void loop()
{
  int reading = digitalRead(in);

  if ((millis() - lastStateChangeTime) > dialHasFinishedRotatingAfterMs) {
    // the dial isn't being dialed, or has just finished being dialed.
    if (needToPrint) {
      // if it's only just finished being dialed, we need to send the number down the serial
      // line and reset the count. We mod the count by 10 because '0' will send 10 pulses.
      Serial.print(count % 10, DEC);
      needToPrint = 0;
      count = 0;
      cleared = 0;
    }
  }

  if (reading != lastState) {
    lastStateChangeTime = millis();
  }
  if ((millis() - lastStateChangeTime) > debounceDelay) {
    // debounce - this happens once it's stablized
    if (reading != trueState) {
      // this means that the switch has either just gone from closed->open or vice versa.
      trueState = reading;
      if (trueState == HIGH) {
        // increment the count of pulses if it's gone high.
        count++;
        needToPrint = 1; // we'll need to print this number (once the dial has finished rotating)
      }
    }
  }
  lastState = reading;
}