Lesson 109: Generate DC Voltage using MCP4725 DAC with LCD and PWM to Voltage Converter with Arduino (5 projects)

Lesson 109: Generate DC Voltage using MCP4725 DAC with LCD and PWM to Voltage Converter with Arduino (5 projects)

Please select other codes for this lecture from the links below.

Part 14: Voltage and Current

In this lesson we learn how to use MCP4725 12 bits Digital To Analog Converter (DAC). The chip and module is explained, datasheet viewed and then using 5 Projects this MCP4725 practically shown. Full wiring diagram and wring shown and how to use the code and library explained.

In Project 3 in lesson 109 Convert PWM duty cycle to Voltage using MCP4725 12bits DAC with Ardunino

Projects

• Project 1: Output 0 to 5V or 0 to 3V depending on which kind of power sources you use for the module. The output shown on digital multimeter.
• Project 2: Serial command to set voltage
• Project 3: PWM duty cycle to Voltage converter
• Project 4: Using two MCP4725 DAC modules
• Project 5: Using Push button to set voltage on LCD

Timing of chapters in the video

  /* 
 * Lesson 109-3: How to convert PWM to Voltage using MCP4725 DAC with Arduino
 * This Arduino project converts PWM to Voltage using MCP4725. 
 * The output voltage will be maxium of to 5.5 (2.7 to 5.5) or whatever you 
 * power it with. .
 * 
 * * Watch Video instrution for this code:https://youtu.be/j_BwZT9z-0g
  
Projects in this video: https://youtu.be/j_BwZT9z-0g
Project 1:Output 0 to 5V or 0 to 3V depending on which kind of power sources you use for the module. The output shown on digital multimeter. 
Project 2: Serial command to set voltage
Project 3 (this project): PWM duty cycle to Voltage converter
Project 4: Using two MCP4725 DAC modules
Project 5: Using Push button to set voltage on LCD

 * Written by Ahmad Shamshiri using Adafruit library for MCP4725
 Sep 26, 2022
 www.Robojax.com
 
  
   * 
   * This code is part of Arduino Step by Step Course which starts here:  https://youtu.be/-6qSrDUA5a8
   * 
   * for library of this code visit http://robojax.com/
   * 
  If you found this tutorial helpful, please support me so I can continue creating 
  content like this. Make a donation using PayPal by credit card https://bit.ly/donate-robojax 
  
 
  
   *  * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
   * This code has been download from Robojax.com
      This program is free software: you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation, either version 3 of the License, or
      (at your option) any later version.
  
      This program is distributed in the hope that it will be useful,
      but WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      GNU General Public License for more details.
  
      You should have received a copy of the GNU General Public License
      along with this program.  If not, see <https://www.gnu.org/licenses/>.
 

    Based on  the Adafruit MCP4725 Library
    ----> http://www.adafruit.com/products/935

    Adafruit invests time and resources providing this open source code,
    please support Adafruit and open-source hardware by purchasing
    products from Adafruit!
*/


#include <Wire.h>
#include <Adafruit_MCP4725.h>
int refV = 4530;//set the voltage source in millivolts

Adafruit_MCP4725 dac;


#define pwmReadPin 2//the pin you are going to read PWM signal from
int averageCounts= 50;//for PWM duty cucle

/// do not change below this
int highTime =0;
int lowTime=0;
float dutyCycle =0;
int averageDutyCycle=0;
int mV;
float V;

void readDutyCycle(void);
void average(void);
void setV(void);
void setmV(void);

void setup(void) {
  Serial.begin(9600);
  Serial.println("PWM to Voltage Coverter");
  pinMode(pwmReadPin, INPUT);
  
  //run i2C scanner to find out the I2C address and enter it below
  //see video for details https://youtu.be/j_BwZT9z-0g
  //get more code from www.Robojax.com 
  dac.begin(0x60);

  Serial.println("www.Robojax.com");
}

void loop(void) {

  readDutyCycle();//read the duty cycle
  pwmToVoltage();
  //printFulleData();
  
//  Serial.print("PWM Dutycycle: ");
//  Serial.print(averageDutyCycle);  
//  Serial.print("%");
//  Serial.print(" is: ");
//  Serial.print(mV);
//  Serial.println("mV");
  
  if(averageDutyCycle >30)
  {
    //do something here
    //Serial.println("Duty cycle is above 30");
  }
    //delay(500);
   //see video for details https://youtu.be/j_BwZT9z-0g
  //get more code from www.Robojax.com   
}//loop end




void pwmToVoltage()
{
 
   //see video for details https://youtu.be/j_BwZT9z-0g
  //get more code from www.Robojax.com  
  setmV(map(averageDutyCycle, 0, 100, 0, refV));
}

/*
 * setmV()
 * sets mV value such as 35mV or 2654mV (2.654V)
 * Written Sep 25, 2022
 * by Ahmad Shamshiri www.Robojax.com
 */
void setmV(int d)
{
  
    mV =d;
    dac.setVoltage(map(d, 0, refV, 0, 4095), false);

}


/*
 * setV()
 * sets Voltage value value in volts such as 3.764
 * Written Sep 25, 2022
 * by Ahmad Shamshiri www.Robojax.com
 */
void setV(float d)
{
    V = d;
    dac.setVoltage( map((d *1000), 0, refV, 0, 4095), false);

}  



void readDutyCycle(){
  highTime = pulseIn(pwmReadPin, HIGH);
  lowTime  = pulseIn(pwmReadPin, LOW); 

  dutyCycle = round((float)highTime /( (float)highTime + (float)lowTime)* 100);
  average();
}

void average()
{
  int sumValue=0;//variable to store sum
  for(int i=0; i< averageCounts; i++)
  {
    sumValue +=dutyCycle;//add each value to the sumValue
  }
  if(averageCounts >0){
    averageDutyCycle = sumValue /averageCounts;//calculate the average and update the variable
  }
  //see video for details https://youtu.be/j_BwZT9z-0g
  //get more code from www.Robojax.com   
}//average end


void printFulleData()
{
  Serial.print("High: ");
  Serial.print(highTime);
  Serial.print("μS Low: ");
  Serial.print(lowTime);
  Serial.print("μS dutyCycle: ");
  Serial.print(dutyCycle);
  Serial.print("% Average: ");
  Serial.print(averageDutyCycle);  
  Serial.println("%");  
}