#include <SPI.h>

#define GSM_1CS 7   //10-???
#define MAX7219_1CS 8
#define MAX7219_2CS 9

/*
#define OP_NOOP   0x00
#define OP_DIGIT0 0x01
#define OP_DIGIT1 0x02
#define OP_DIGIT2 0x03
#define OP_DIGIT3 0x04
#define OP_DIGIT4 0x05
#define OP_DIGIT5 0x06
#define OP_DIGIT6 0x07
#define OP_DIGIT7 0x08
*/
#define OP_DECODEMODE  0x09
#define OP_INTENSITY   0x0a
#define OP_SCANLIMIT   0x0b
#define OP_SHUTDOWN    0x0c
#define OP_DISPLAYTEST 0x0f
/*
void shift(byte send_to_address, byte send_this_data)
{
  digitalWrite(MAX7219_Chip_Select, LOW);
  shiftOut(MAX7219_Data_IN, MAX7219_Clock, MSBFIRST, send_to_address);
  shiftOut(MAX7219_Data_IN, MAX7219_Clock, MSBFIRST, send_this_data);
  digitalWrite(MAX7219_Chip_Select, HIGH);
}
*/
void setup() {
  Serial.begin(9600);

  pinMode(10, OUTPUT);  //CS for SPI, Is Need???
  digitalWrite(10, HIGH);
  pinMode(GSM_1CS, OUTPUT);
  digitalWrite(GSM_1CS, HIGH);
  pinMode(MAX7219_1CS, OUTPUT);
  digitalWrite(MAX7219_1CS, HIGH);
  pinMode(MAX7219_2CS, OUTPUT);
  digitalWrite(MAX7219_1CS, HIGH);

    // start the SPI library:
  //Set SPI Speed 125kHz!!!
  SPI.setClockDivider(SPI_CLOCK_DIV128);
  SPI.begin();

  delay(200);

  //Setup of MAX7219 chip, Display 1
  writeRegister(MAX7219_1CS, OP_DISPLAYTEST, 0x00); //display test register - test mode off
  writeRegister(MAX7219_1CS, OP_SHUTDOWN   , 0x01); //shutdown register - normal operation
  writeRegister(MAX7219_1CS, OP_SCANLIMIT  , 0x07); //scan limit register - display digits 0 thru 7
  writeRegister(MAX7219_1CS, OP_INTENSITY  , 0x0f); //intensity register - max brightness
  writeRegister(MAX7219_1CS, OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits
 //Setup of MAX7219 chip, Display 2
  writeRegister(MAX7219_2CS, OP_DISPLAYTEST, 0x00); //display test register - test mode off
  writeRegister(MAX7219_2CS, OP_SHUTDOWN   , 0x01); //shutdown register - normal operation
  writeRegister(MAX7219_2CS, OP_SCANLIMIT  , 0x07); //scan limit register - display digits 0 thru 7
  writeRegister(MAX7219_2CS, OP_INTENSITY  , 0x0f); //intensity register - max brightness
  writeRegister(MAX7219_2CS, OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits

}

void loop() {
  // Display Test on
  Serial.println("Display Test");
  writeRegister(MAX7219_1CS, OP_INTENSITY, 0);
  writeRegister(MAX7219_2CS, OP_INTENSITY, 0);

  writeRegister(MAX7219_1CS, OP_DISPLAYTEST , 0x01); // Display test on
  writeRegister(MAX7219_2CS, OP_DISPLAYTEST , 0x01); // Display test on
  //delay(2000);

  for (int i = 0; i < 16; i++) {
    writeRegister(MAX7219_1CS, OP_INTENSITY, i);
    writeRegister(MAX7219_2CS, OP_INTENSITY, i);
    delay(100);
  }
    for (int i = 0; i < 16; i++) {
    writeRegister(MAX7219_1CS, OP_INTENSITY, 15-i);
    writeRegister(MAX7219_2CS, OP_INTENSITY, 15-i);
    delay(100);
  }

  writeRegister(MAX7219_1CS, OP_DISPLAYTEST , 0x00); // Display test off
  writeRegister(MAX7219_2CS, OP_DISPLAYTEST , 0x00); // Display test off
  delay(1000);

  writeRegister(MAX7219_1CS, OP_INTENSITY, 10);
  writeRegister(MAX7219_2CS, OP_INTENSITY, 10);
  writeRegister(MAX7219_1CS, OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits
  writeRegister(MAX7219_2CS, OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits

  byte OutB1[4] = {0x00, 0x00, 0x00, 0x80};
  writeDispFlow(MAX7219_1CS, OutB1);
/*
  writeRegister(MAX7219_1CS, OP_DIGIT0, 0x00);
  writeRegister(MAX7219_1CS, OP_DIGIT1, 0x00);
  writeRegister(MAX7219_1CS, OP_DIGIT2, 0x00);
  writeRegister(MAX7219_1CS, OP_DIGIT3, 0x80);
*/
  byte OutB2[4] = {0x0f, 0x00, 0x80, 0x00};
  writeDispO2(MAX7219_1CS, OutB2);
  /*
  writeRegister(MAX7219_1CS, OP_DIGIT4, 0x0f);
  writeRegister(MAX7219_1CS, OP_DIGIT5, 0x00);
  writeRegister(MAX7219_1CS, OP_DIGIT6, 0x80);
  writeRegister(MAX7219_1CS, OP_DIGIT7, 0x00);
*/
  byte OutB3[4] = {0x00, 0x00, 0x80, 0x00};
  writeDispFlow(MAX7219_2CS, OutB3);
/*
  writeRegister(MAX7219_2CS, OP_DIGIT0, 0x00);
  writeRegister(MAX7219_2CS, OP_DIGIT1, 0x00);
  writeRegister(MAX7219_2CS, OP_DIGIT2, 0x80);
  writeRegister(MAX7219_2CS, OP_DIGIT3, 0x00);
*/
  byte OutB4[4] = {0x0f, 0x00, 0x80, 0x00};
  writeDispO2(MAX7219_2CS, OutB4);
/*  
  writeRegister(MAX7219_2CS, OP_DIGIT4, 0x0f);
  writeRegister(MAX7219_2CS, OP_DIGIT5, 0x00);
  writeRegister(MAX7219_2CS, OP_DIGIT6, 0x80);
  writeRegister(MAX7219_2CS, OP_DIGIT7, 0x00);
*/
  delay(10000);
/*
  // Display Test on
  Serial.println("Shutdown");
  shift(OP_SHUTDOWN , 0x00); // Display test on
  delay(2000);
  shift(OP_SHUTDOWN , 0x01); // Display test off

  delay(1000);

  Serial.println("Scan Limit test (3)");
  shift(OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits
  shift(OP_DIGIT7, 0x08); //digit 7 (leftmost digit) data
  shift(OP_DIGIT6, 0x08);
  shift(OP_DIGIT5, 0x08);
  shift(OP_DIGIT4, 0x08);
  shift(OP_DIGIT3, 0x08);
  shift(OP_DIGIT2, 0x08);
  shift(OP_DIGIT1, 0x08);
  shift(OP_DIGIT0, 0x08); //digit 0 (rightmost digit) data  
  shift(OP_SCANLIMIT, 0x03);
  delay(1000);
  Serial.println("Scan Limit test (7)");
  shift(OP_SCANLIMIT, 0x07);
  delay(1000);

  Serial.println("Intensity test");
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, 15-i);
    delay(100);
  }
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, i);
    delay(100);
  }
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, 15-i);
    delay(100);
  }
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, i);
    delay(100);
  }
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, 15-i);
    delay(100);
  }
  for (int i = 0; i < 16; i++) {
    shift(OP_INTENSITY, i);
    delay(100);
  }
  shift(OP_INTENSITY, 0xf);

  //Data transfer
  Serial.println("BCD with decimal point");
  shift(OP_DECODEMODE , 0xff); //decode mode register - CodeB decode all digits
  shift(OP_DIGIT7, 0x80); //digit 7 (leftmost digit) data
  shift(OP_DIGIT6, 0x81);
  shift(OP_DIGIT5, 0x82);
  shift(OP_DIGIT4, 0x83);
  shift(OP_DIGIT3, 0x84);
  shift(OP_DIGIT2, 0x85);
  shift(OP_DIGIT1, 0x86);
  shift(OP_DIGIT0, 0x87); //digit 0 (rightmost digit) data
  delay(1000);

  Serial.println("BCD without decimal point");
  shift(OP_DIGIT7, 0x08); //digit 7 (leftmost digit) data
  shift(OP_DIGIT6, 0x09);
  shift(OP_DIGIT5, 0x0a); //= '-'
  shift(OP_DIGIT4, 0x0b); //= 'E'
  shift(OP_DIGIT3, 0x0c); //= 'H'
  shift(OP_DIGIT2, 0x0d); //= 'L'
  shift(OP_DIGIT1, 0x0e); //= 'P'
  shift(OP_DIGIT0, 0x0f); //digit 0 (rightmost digit) data //= ' '
  delay(1000);

  shift(OP_DECODEMODE , 0x00); //decode mode register - CodeB decode all digits

  Serial.println("Cleared segments");
  shift(OP_DIGIT7, 0x00); //digit 7 (leftmost digit) data
  shift(OP_DIGIT6, 0x00);
  shift(OP_DIGIT5, 0x00);
  shift(OP_DIGIT4, 0x00);
  shift(OP_DIGIT3, 0x00);
  shift(OP_DIGIT2, 0x00);
  shift(OP_DIGIT1, 0x00);
  shift(OP_DIGIT0, 0x00); //digit 0 (rightmost digit) data

  delay(1000);

  Serial.println("Segment test");
  uint8_t x = 0x80;
  for (int i = 0; i < 8; i++) {
    shift(OP_DIGIT7, x); //digit 7 (leftmost digit) data
    shift(OP_DIGIT6, x);
    shift(OP_DIGIT5, x);
    shift(OP_DIGIT4, x);
    shift(OP_DIGIT3, x);
    shift(OP_DIGIT2, x);
    shift(OP_DIGIT1, x);
    shift(OP_DIGIT0, x); //digit 0 (rightmost digit) data
    x = x >> 1;
    delay(500);
  }
*/  
}

//Sends a write command to SPI
void writeRegister(byte thisDisplay, byte thisRegister, byte thisValue) {
  // take the chip select low to select the device:
  digitalWrite(thisDisplay, LOW);
  //SPI.transfer(dataToSend); //Send register location
  SPI.transfer(thisRegister); //Send register location
  SPI.transfer(thisValue);  //Send value to record into register
  // take the chip select high to de-select:
  digitalWrite(thisDisplay, HIGH);
}

//Write to Display 1/1 - 'Xn' or 'O2'
void writeDispO2(byte thisDisplay, byte Data[4]) {
    for (int i = 5; i < 9; i++) {
    writeRegister(thisDisplay, i, Data[i-5]);
    }
}

//Write to Display 1/2 - 'Flow' or 'Volume'
void writeDispFlow(byte thisDisplay, byte Data[4]) {
    for (int i = 1; i < 5; i++) {
    writeRegister(thisDisplay, i, Data[i-1]);
    }
}