//Guitar frequency to 1V/Oct CV output.
//Input signal via fundamental extractor and Schmitt trigger
//Mick Bailey 2023
//Version 1.0


#include <log2.h> //Log(2) library
#include <Adafruit_MCP4725.h>
Adafruit_MCP4725 MCP4725;

int Htime;                //integer for storing high time
int Ltime;                //integer for storing low time
float Ttime;              // integer for storing total time of a cycle
float frequency;          //storing frequency
float mv_conversion;      // frequency to voltage conversion
int dac_value;

void setup()

{
  pinMode(8, INPUT);       //guitar input pin 8
  MCP4725.begin(0x60);     // set the I2C Address of the MCP4725
}

void loop()

{

  Htime = pulseIn(8, HIGH);   //read high time
  Ltime = pulseIn(8, LOW);    //read low time
  Ttime = Htime + Ltime;      //calculate total time
  frequency = 1000000 / Ttime;  //calculate frequency
  mv_conversion = log2(frequency / 55) * 1000;  //frequency to voltage in millivolts conversion
  dac_value = (mv_conversion / 5000) * 4095; // get DAC value as an integer
  MCP4725.setVoltage(dac_value, false);

}