/* Input Expander Module


This sample program makes the module a binary counter.
A sample circuit is shown in this folder of how 
the input expander may be tested independently without
an output expander module.

This test program checks the functionality of the input expander
module using the software's serial monitor.

JP2 pin assignments:
Din on digital pin 11
Str on digital pin 12
Clk on digital pin 13

Codes by:
eGizmo Mechatronix Central
Manila, Philippines
April 4, 2013

*/

// constants won't change. They're used here to 
// set pin numbers:
const int INCLK = 13;     // input expander CLK pin
const int DIN =  11;      // input expander DOUT pin
const int INSTR =  12;      // input expander STR pin
const int OUTCLK = A2;     // output expander CLK pin
const int DOUT =  A1;      // output expander DIN pin
const int OUTSTR =  A0;      // output expander STR pin

// Set delay, bytes, counter, and mask.
int d = 100;
byte byte1;
byte counter;
byte mask;


void setup() 
{          
  // Initialize serial monitor with 9600 baud.
  Serial.begin(9600);  
  // Set pins to output i stands for increment.
  pinMode(INCLK, OUTPUT);     // Set Clock in as output
  pinMode(DIN, INPUT);     // Set Data in as input
  pinMode(INSTR, OUTPUT);     // Set Strobe in as output
  pinMode(OUTCLK, OUTPUT);     // Set Clock out as output
  pinMode(DOUT, OUTPUT);     // Set Data out as output
  pinMode(OUTSTR, OUTPUT);     // Set Strobe out as output
}


// Set clock in cycle
void CLKIN(){
  digitalWrite(INCLK, HIGH);
  digitalWrite(INCLK, LOW);
}  

// Set clock out cycle
void CLKOUT(){
  digitalWrite(OUTCLK, HIGH);
  digitalWrite(OUTCLK, LOW);
}  

// Set strobe in cycle
void STRIN(){
  digitalWrite(INSTR, HIGH);
  digitalWrite(INSTR, LOW);
}  

// Set strobe out cycle
void STROUT(){
  digitalWrite(INSTR, HIGH);
  digitalWrite(INSTR, LOW);
}  



// Set LED outputs
void out_LEDs()
{
  for(mask=1; mask>0;)
  { 
    if(byte1 & mask)
      digitalWrite(DOUT, HIGH);
    else  
      digitalWrite(DOUT, LOW);
    CLKOUT();
    mask = mask << 1;
  }
  STROUT();
}



byte read_LEDs()
{
  byte byte1 = 0;

  digitalWrite(INSTR, LOW);
  CLKIN();
  digitalWrite(INSTR, HIGH);
  for(mask=1; mask>0;)
  { 
    if(digitalRead(DIN) == HIGH)
      byte1 |= mask; 
    CLKIN();
    mask = mask << 1;
  }
  return byte1; // Returns the value
}



void loop() 
{
byte reading = read_LEDs(); 
// Set reading as the variable for LED output
Serial.println(reading);

}