/* JogControllerTest Program
 *  Author: Pete Holm
 *  based on a similar CD4021B Shift Register example (shiftIn, by Carlyn Maw)
 */
#include <SoftwareSerial.h>


SoftwareSerial mySerial(1, 0); // RX, TX

//define where pins are - these are ardunio pins not ATtiny pins
int latchPin = 3;
int dataPin = 7;
int clockPin = 8;

//Define variables to hold the data
//for shift register.
//starting with a non-zero numbers can help
//troubleshoot
byte switchVar1 = 72;  //01001000

void setup() {
  // Open serial communications and wait for port to open: 
  // set the data rate for the SoftwareSerial port
  mySerial.begin(115200);

  //define pin modes
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, INPUT);
}


void loop() { // run over and over

   //Pulse the latch pin:
  //set it to 1 to collect parallel data
  digitalWrite(latchPin,1);
  //set it to 1 to collect parallel data, wait
  delayMicroseconds(20);
  //set it to 0 to transmit data serially  
  digitalWrite(latchPin,0);

  //while the shift register is in serial mode
  //collect each shift register into a byte
  //the register attached to the chip comes in first
  switchVar1 = shiftIn(dataPin, clockPin);

  if ((switchVar1 != 0) && (switchVar1 != 1000000)) {
    mySerial.print(switchVar1, BIN);
  }

// Place holder to print out the direction button pressed

    if (switchVar1 & (1 << 0) ){
      //print the value of the array location
      mySerial.println(": stop");
    } else if (switchVar1 & (1 << 1) ){
      //print the value of the array location
      mySerial.println(": run");
    } else if (switchVar1 & (1 << 2) ){
      //print the value of the array location
      mySerial.println(": in");
    } else if (switchVar1 & (1 << 3) ){
      //print the value of the array location
      mySerial.println(": out");  
     } else if (switchVar1 & (1 << 4) ){
      //print the value of the array location
      mySerial.println(": down"); 
     } else if (switchVar1 & (1 << 5) ){
      //print the value of the array location
      mySerial.println(": right");  
     } else if (switchVar1 & (1 << 6) ){
      //print the value of the array location
     // mySerial.println(": left"); 
     } else if (switchVar1 & (1 << 7) ){
      //print the value of the array location
      mySerial.println(": up");      
     }

  delay(250);

}

////// shiftIn function
///// just needs the location of the data pin and the clock pin
///// it returns a byte with each bit in the byte corresponding
///// to a pin on the shift register. leftBit 7 = Pin 7 / Bit 0= Pin 0

byte shiftIn(int myDataPin, int myClockPin) {
  int i;
  int temp = 0;
  int pinState;
  byte myDataIn = 0;

  pinMode(myClockPin, OUTPUT);
  pinMode(myDataPin, INPUT);
//we will be holding the clock pin high 8 times (0,..,7) at the
//end of each time through the for loop

//at the begining of each loop when we set the clock low, it will
//be doing the necessary low to high drop to cause the shift
//register's DataPin to change state based on the value
//of the next bit in its serial information flow.
//The register transmits the information about the pins from pin 7 to pin 0
//so that is why our function counts down
  for (i=7; i>=0; i--)
  {
    digitalWrite(myClockPin, 0);
    delayMicroseconds(0.2);
    temp = digitalRead(myDataPin);
    if (temp) {
      pinState = 1;
      //set the bit to 0 no matter what
      myDataIn = myDataIn | (1 << i);
    }
    else {
      //turn it off -- only necessary for debuging
     //print statement since myDataIn starts as 0
      pinState = 0;
    }

    digitalWrite(myClockPin, 1);
  }

  return myDataIn;
}