Filament Measuring Device (Page 2 of 2)

Thanks Tim.  Actually one thing was wrong.  The GND on the digital gauge needed to be connected to GND on the arduino.

The system is up and running, it does about 1-2 measurements per second.

Here's a test program for checking the wiring to the arduino.

int pin;

void setup(){
  pin = 22;
  Serial.begin(9600); 
  pinMode(pin, INPUT);
}

void loop(){
  Serial.print("PIN ");
  Serial.print(pin);
  Serial.print(" is ");

  if (digitalRead(pin) == LOW)
    Serial.write("LOW");
  else
    Serial.write("HIGH");
  Serial.write("\n");   
  delay(1000);
}

This is the sketch to read the digital thickness gauge (or a digital caliper)

int i;
int sign;
long value;
float result;
int clockpin = 22;  
int datapin = 23;
unsigned long tempmicros;

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

void loop () {
  while (digitalRead(clockpin)==HIGH) {} //if clock is LOW wait until it turns to HIGH
  tempmicros=micros();
  while (digitalRead(clockpin)==LOW) {} //wait for the end of the HIGH pulse
  if ((micros()-tempmicros)>500) { //if the HIGH pulse was longer than 500 micros we are at the start of a new bit sequence
    decode(); //decode the bit sequence
  }
}

void decode() {
  sign=1;
  value=0;

  for (i=0;i<23;i++) {
    while (digitalRead(clockpin)==HIGH) { } //wait until clock returns to HIGH- the first bit is not needed
    while (digitalRead(clockpin)==LOW) {} //wait until clock returns to LOW

    if (digitalRead(datapin)==LOW) {

      if (i<20) {
        value|= 1<<i;
      }

      if (i==20) {
        sign=-1;
      }

    }
    
  }

  result=(value*sign)/100.00;    
  Serial.println(result,2); //print result with 2 decimals
  delay(1000);
}

RoTorIT wrote:

Is this implemented in any 3D printer FirmWare? like Sprinter or Marlin so it can be used to adjust the extruder feedrate/extrusion multiplier on the fly when printing?

No that I know of. 

It could be implemented by reading from a separate arduino and using a program/macro to control the flow rate in Rep-Host.