Interfacing with multiple Digital Dial Indicators (SPC outputs)

I am attempting to make my Arduino Uno or any other model read multiple SPC outputs at once and then transfer that data to excel using PLX-DAQ. I have figured out how to read and transfer the data from a single gauge, but I cannot figure out how to tweek the code in order to transfer the data from 4 different gauges. I am not even sure if it is actually possible. The code I am using is posted below.

int req = 5; //mic REQ line goes to pin 5 through q1 (arduino high pulls request line low)

int dat = 2; //mic Data line goes to pin 2

int clk = 3; //mic Clock line goes to pin 3

int i = 0; int j = 0; int k = 0; int q = 0;

byte mydata[14];

float num;

void setup() {

Serial.begin(9600);

Serial.println(“CLEARDATA”);

Serial.println(“LABEL,Time,Timer,Data”);

Serial.println(“RESETTIMER”);

pinMode(req, OUTPUT);

pinMode(clk, INPUT_PULLUP);

pinMode(dat, INPUT_PULLUP);

digitalWrite(req, LOW); // set request at LOW

}

void loop() { // get data from mic

digitalWrite(req, HIGH); // generate set request

for (i = 0; i < 13; i++ ) {

k = 0;

for (j = 0; j < 4; j++) {

while ( digitalRead(clk) == LOW) { // hold until clock is high

}

while ( digitalRead(clk) == HIGH) { // hold until clock is low

}

bitWrite(k, j, (digitalRead(dat) & 0x1)); // read data bits, and reverse order )

}

// extract data

mydata = k;

  • }*

  • // sign = mydata[4];*

  • // decimal = mydata[11];*

  • // units = mydata[12];*

  • // assemble measurement from bytes*

  • char buf[7];*

  • for (q = 0; q < 6; q++) {*

  • buf[q] = mydata[q + 5] + ‘0’;*

  • buf[6] = 0;*

  • num = atol(buf); //assembled measurement, no decimal place added*

  • Serial.print(“DATA,TIME,TIMER,”);*

  • Serial.print(num / 1000, 3); //add decimal*

  • Serial.println(’\n’);*

  • delay(500);*

  • }*

  • //delay(500);*
    }

You need to gauges connected to different pins on your arduino or you need to do some sort of multiplexing