//By NMD weerasinghe COTMD
// To demonstrate Serial In Parallel Out (SIPO) Shift Register and
// Parallel in Serial Out (PISO) Shift Registor 

#define ClkDelay 500 //delay in milliseconds of each half of clock pulse
#define ClockPin 2
#define SerialDataPin 3
#define LatchPin 4
#define PISOClkEn 5 // Piso Clock enable active low
#define PISOPrllLoad 6 // PISO Parallel Load active Low
#define Maxbit 7
#define printEnable 0 // if 1 enable Serial print debug details

void sendSerialdata(int fpattern, bool order);
void sendClockpulse(int NoOfPulse);
void LoadSIPOandRun();

int pattern = 0b10101010;
int mask = 0b0000001;
//int Maxbit = 7;




void setup() {

pattern = 0b11100100;

pinMode(ClockPin, OUTPUT);
pinMode(SerialDataPin, OUTPUT);
pinMode(LatchPin, OUTPUT);
pinMode(PISOClkEn, OUTPUT);
pinMode(PISOPrllLoad, OUTPUT);

Serial.begin(9600);
if(printEnable) Serial.begin(9600);
delay(1000);
digitalWrite(ClockPin,LOW); // clock pin to low initially
digitalWrite(PISOClkEn,HIGH); // disable SIPO clock pin  initially
digitalWrite(PISOPrllLoad,HIGH);// disable SIPO parallel load pin  initially

//sendClockpulse(8);

sendSerialdata(pattern,false); // true left to right false right to left to SIPO
delay(ClkDelay*3);
//LoadSIPOandRun();
sendSerialdata(pattern,true); // to SIPO
delay(ClkDelay*3);



}

void loop() {
  // put your main code here, to run repeatedly:


}


void LoadSIPOandRun()
{
    digitalWrite(PISOClkEn,LOW); // enable SIPO clock pin
    digitalWrite(PISOPrllLoad,LOW);// enable SIPO parallel load pin
    sendClockpulse(8);
    digitalWrite(PISOClkEn,HIGH); // disable SIPO clock pin
    digitalWrite(PISOPrllLoad,HIGH);// disable SIPO parallel load pin

}

void sendSerialdata(int fpattern, bool order) //to SIPO
{
  
  if(order) // left to right
  {
    for(int bitNo = 0; bitNo < Maxbit + 1; bitNo++ )
      {
        digitalWrite(LatchPin,LOW);
        int pattern = fpattern >> bitNo;
        bool bit  = pattern & mask;

        if(printEnable)
        {
            Serial.println(bit);
            Serial.println(pattern,BIN);
        }
        digitalWrite(SerialDataPin,bit); 
        digitalWrite(ClockPin,HIGH);
        delay(ClkDelay);
        digitalWrite(ClockPin,LOW);
        delay(ClkDelay);
        digitalWrite(LatchPin,HIGH);
      }

  }
  else // right to left
  {
     for(int bitNo = Maxbit; bitNo > -1; bitNo--)
      {
        digitalWrite(LatchPin,LOW);
        int pattern = fpattern >> bitNo;
        bool bit  = pattern & mask;

        if(printEnable)
        {
            Serial.println(bit);
            Serial.println(pattern,BIN);
        }
        digitalWrite(SerialDataPin,bit);
        digitalWrite(ClockPin,HIGH);
        delay(ClkDelay);
        digitalWrite(ClockPin,LOW);
        delay(ClkDelay);
        digitalWrite(LatchPin,HIGH);
      }
  }
 
}


void sendClockpulse(int NoOfPulse)
{
  //Serial.println("Entclockpulse");
  for (int i = 0 ; i < NoOfPulse; i++)
  {
        //Serial.println("clockpulse");
        digitalWrite(ClockPin,HIGH);
        delay(ClkDelay);
        digitalWrite(ClockPin,LOW);
  }

}