// accurate clock is not needed for callibration
// Callibration for internal I/V resistor 10k ... 8.5-Digits multimeter is needed

// connection: D2=BCK, D3=LRCK, D4=DATA

// 1) offset
// short D10 with GND for offset adjustment
// set with trimmer TR3 (TR4) voltage 0.000305mV on tpL (tpR)

// 2) maximum Positive value
// short D11 with GND for maximum Positive value adjustment
// set with trimmer TR1 (TR2) voltage 10.000000V on tpL (tpR)

// 3) maximum Negative value
// short D12 with GND for maximum Negative value adjustment
// check if on tpL (tpR) is voltage -9.999695V
// if not, adjust it with trimmer TR1 (TR2)

// repeat process untill you fit the values


long oldTime_1ms = 0;
uint32_t timer_500ms = 0;
uint32_t timer_1000ms = 0;
uint32_t counter_32 = 0;
int counter_data = 0;


void setup() {
  // put your setup code here, to run once:
  pinMode(2, OUTPUT); // BCK
  pinMode(3, OUTPUT); // LRCK
  pinMode(4, OUTPUT); // DATA
  pinMode(10, INPUT_PULLUP); // short D10 with GND for offset adjustment
  pinMode(11, INPUT_PULLUP); // short D11 with GND for maximum positive current (voltage) output
  pinMode(12, INPUT_PULLUP); // short D12 with GND for minimum positive current (voltage) output
  digitalWrite(2, LOW);
  digitalWrite(3, HIGH);
  digitalWrite(4, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  if ((millis() - oldTime_1ms) >= 1) { // for 8 MHz delay is 2ms, for 16 MHz delay is 1ms
    oldTime_1ms = millis();

    timer_500ms++;
    timer_1000ms++;
  }

  // Generate BCK and LRCK
  if (timer_500ms >= 500) {
    timer_500ms = 0;
    digitalWrite(2, !digitalRead(2));
    counter_32++;
    if (counter_32 >= (2 * 32)) { // 2x because it counts on every half BCK cycle
      counter_32 = 0;
      digitalWrite(3, !digitalRead(3));
    }
  }

  if (timer_1000ms >= 1000) {
    timer_1000ms = 0;
    if (counter_data >= 31) {
      counter_data = -1;
    }

    // Callibration for internal I/V resistor 10k ... 8.5-Digits multimeter is needed
    // Send data for offset callibration (1LSB = 0.0305uA ==> 0.0305uA x 10k = 0.305uV = 0.000305mV on tpL/tpR)
    if (digitalRead(10) == LOW) {
      if (counter_data == -1) digitalWrite(4, 0); // bit 32
      if (counter_data == 0) digitalWrite(4, 0); // 0 (MSB)
      if (counter_data == 1) digitalWrite(4, 0); // 1
      if (counter_data == 2) digitalWrite(4, 0); // 2
      if (counter_data == 3) digitalWrite(4, 0); // 3
      if (counter_data == 4) digitalWrite(4, 0); // 4
      if (counter_data == 5) digitalWrite(4, 0); // 5
      if (counter_data == 6) digitalWrite(4, 0); // 6
      if (counter_data == 7) digitalWrite(4, 0); // 7
      if (counter_data == 8) digitalWrite(4, 0); // 8
      if (counter_data == 9) digitalWrite(4, 0); // 9
      if (counter_data == 10) digitalWrite(4, 0); // 10
      if (counter_data == 11) digitalWrite(4, 0); // 11
      if (counter_data == 12) digitalWrite(4, 0); // 12
      if (counter_data == 13) digitalWrite(4, 0); // 13
      if (counter_data == 14) digitalWrite(4, 0); // 14
      if (counter_data == 15) digitalWrite(4, 1); // 15 (LSB)
      if (counter_data > 15) digitalWrite(4, 0); // x
    }

    // Send data for max Pos callibration (1.0000000mA ==> 1.0000000mA x 10k = 10.000000V on tpL/tpR)
    if (digitalRead(11) == LOW) {
      if (counter_data == -1) digitalWrite(4, 0); // bit 32
      if (counter_data == 0) digitalWrite(4, 1); // 0 (MSB)
      if (counter_data == 1) digitalWrite(4, 1); // 1
      if (counter_data == 2) digitalWrite(4, 1); // 2
      if (counter_data == 3) digitalWrite(4, 1); // 3
      if (counter_data == 4) digitalWrite(4, 1); // 4
      if (counter_data == 5) digitalWrite(4, 1); // 5
      if (counter_data == 6) digitalWrite(4, 1); // 6
      if (counter_data == 7) digitalWrite(4, 1); // 7
      if (counter_data == 8) digitalWrite(4, 1); // 8
      if (counter_data == 9) digitalWrite(4, 1); // 9
      if (counter_data == 10) digitalWrite(4, 1); // 10
      if (counter_data == 11) digitalWrite(4, 1); // 11
      if (counter_data == 12) digitalWrite(4, 1); // 12
      if (counter_data == 13) digitalWrite(4, 1); // 13
      if (counter_data == 14) digitalWrite(4, 1); // 14
      if (counter_data == 15) digitalWrite(4, 1); // 15 (LSB)
      if (counter_data > 15) digitalWrite(4, 0); // x
    }

    // Send data for max Neg callibration (-0.9999695mA ==> -0.9999695mA x 10k = -9.999695V on tpL/tpR)
    if (digitalRead(12) == LOW) {
      if (counter_data == -1) digitalWrite(4, 0); // bit 32
      if (counter_data == 0) digitalWrite(4, 0); // 0 (MSB)
      if (counter_data == 1) digitalWrite(4, 0); // 1
      if (counter_data == 2) digitalWrite(4, 0); // 2
      if (counter_data == 3) digitalWrite(4, 0); // 3
      if (counter_data == 4) digitalWrite(4, 0); // 4
      if (counter_data == 5) digitalWrite(4, 0); // 5
      if (counter_data == 6) digitalWrite(4, 0); // 6
      if (counter_data == 7) digitalWrite(4, 0); // 7
      if (counter_data == 8) digitalWrite(4, 0); // 8
      if (counter_data == 9) digitalWrite(4, 0); // 9
      if (counter_data == 10) digitalWrite(4, 0); // 10
      if (counter_data == 11) digitalWrite(4, 0); // 11
      if (counter_data == 12) digitalWrite(4, 0); // 12
      if (counter_data == 13) digitalWrite(4, 0); // 13
      if (counter_data == 14) digitalWrite(4, 0); // 14
      if (counter_data == 15) digitalWrite(4, 0); // 15 (LSB)
      if (counter_data > 15) digitalWrite(4, 0); // x
    }

    counter_data++;
  }



}