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Interfacing PCF8591 AD/DA Analog-Digital Module with Arduino

Table of Contents

PCF8591 AD/DA Features

The PCF8591 is a single-chip, single-supply low power 8-bit CMOS data acquisition device. This chip has four analog inputs, one analog output, and a serial I2C-bus interface.

The PCF8591 module has 4 pins on the left, which include the power pins and the I2C connection pins. The 8 right pins with 4 jumpers on them also work with signals:

  •  AOUT: Module DAC output interface
  •  AINO: chip analog input interface
  •  AIN1: chip analog input interface
  •  AIN2: chip analog input interface
  •  AIN3: chip analog input interface
  •  INPUT2: Signal input port that thermistor is connected to it
  •  INPUT1: Signal input port that photoresistor is connected to it
  •  INPUT0: Signal input port that potentiometer is connected to it

You can download the datasheet of this module here.

PCF8591 Module Pinout

This sensor has 4 pins:

  •  VIN: Module power supply – 5 V
  •  GND: Ground
  •  SLC: I2C clock
  •  SDA: I2C data

You can see the pinout of this module in the image bellow.

Required Materials

Hardware Components

Arduino UNO R3 × 1
PCF8591 AD/DA Analog-Digital Module × 1
Male to Female Jumper Wire × 1

Software Apps

Arduino IDE

Interfacing PCF8591 Module with Arduino

Step 1: Circuit

The following circuit shows how you should connect Arduino to PCF8591 module. Connect wires accordingly.

Step 2: Code

Install the following library on your Arduino first.


If you need more help with installing a library on Arduino, read this tutorial: How to Install an Arduino Library

Upload the following code to your Arduino.
  modified on Sep 23, 2020
  Modified by MohammedDamirchi from

#include <Adafruit_PCF8591.h>
// Make sure that this is set to the value in volts of VCC
Adafruit_PCF8591 pcf = Adafruit_PCF8591();

void setup() {
  while (!Serial)

  Serial.println("# Adafruit PCF8591 demo");
  if (!pcf.begin()) {
    Serial.println("# Adafruit PCF8591 not found!");
    while (1)
  Serial.println("# Adafruit PCF8591 found");


uint8_t dac_counter = 0;

void loop() {
  // Make a triangle wave on the DAC output
  dac_counter = dac_counter + 10;
  Serial.print("AIN0: ");
  Serial.print(int_to_volts(pcf.analogRead(0), 8, ADC_REFERENCE_VOLTAGE));
  Serial.print("\t AIN1: ");
  Serial.print(int_to_volts(pcf.analogRead(1), 8, ADC_REFERENCE_VOLTAGE));
  Serial.print("\t AIN2: ");
  Serial.print(int_to_volts(pcf.analogRead(2), 8, ADC_REFERENCE_VOLTAGE));
  Serial.print("\t AIN3: ");
  Serial.print(int_to_volts(pcf.analogRead(3), 8, ADC_REFERENCE_VOLTAGE));

float int_to_volts(uint16_t dac_value, uint8_t bits, float logic_level) {
  return (((float)dac_value / ((1 << bits) - 1)) * logic_level);
After running the code, you will see the following image in the serial monitor.

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