k80-linux-cooling/Arduino/rx_speed.ino

#include "SerialTransfer.h"

SerialTransfer myTransfer;

const byte OC1A_PIN = 9;
const byte OC1B_PIN = 10;

const word PWM_FREQ_HZ = 25000;  //Adjust this value to adjust the frequency (Frequency in HZ!) (Set currently to 25kHZ)
const word TCNT1_TOP = 16000000/(2*PWM_FREQ_HZ);

struct STRUCT {
  char val;
} myStruct;

void setup() {
  // Setup Serial transfer with PC
  Serial.begin(115200);
  myTransfer.begin(Serial);

  pinMode(OC1A_PIN, OUTPUT);

  // Clear Timer1 control and count registers
  TCCR1A = 0;
  TCCR1B = 0;
  TCNT1  = 0;

  // Set Timer1 configuration
  // COM1A(1:0) = 0b10   (Output A clear rising/set falling)
  // COM1B(1:0) = 0b00   (Output B normal operation)
  // WGM(13:10) = 0b1010 (Phase correct PWM)
  // ICNC1      = 0b0    (Input capture noise canceler disabled)
  // ICES1      = 0b0    (Input capture edge select disabled)
  // CS(12:10)  = 0b001  (Input clock select = clock/1)

  TCCR1A |= (1 << COM1A1) | (1 << WGM11);
  TCCR1B |= (1 << WGM13) | (1 << CS10);
  ICR1 = TCNT1_TOP;
}

void loop() {

  if(myTransfer.available())
  {

    // send all received data back to Python
    for(uint16_t i=0; i < myTransfer.bytesRead; i++){
      myTransfer.packet.txBuff[i] = myTransfer.packet.rxBuff[i];
    }
    myTransfer.sendData(myTransfer.bytesRead);

    uint16_t recSize = 0;
    recSize = myTransfer.rxObj(myStruct, recSize);
    int x = myStruct.val;

    setPwmDuty(x);
  }
}

void setPwmDuty(byte duty) {
  OCR1A = (word) (duty*TCNT1_TOP)/100;
}