PCF8591 8-Bit AD/DA Converter Module 4-Channel Analog Input & 1-Channel Output with I2C Interface

Quick Introduction: Running out of Analogue Pins on your ESP8266? Need to read analogue sensors with a Raspberry Pi that has no built-in ADC? The Pro-Grade PCF8591 AD/DA Converter Module is the classic solution. It adds four 8-bit Analogue-to-Digital (ADC) inputs and one 8-bit Digital-to-Analogue (DAC) output to any microcontroller using just two wires (I2C). Uniquely designed for learning and prototyping, this module comes pre-loaded with three onboard test components—a potentiometer, thermistor, and photoresistor—allowing you to start coding and testing analogue signals immediately without wiring up external breadboards.

Detailed Specifications

• Main Chip: NXP PCF8591.

• Operating Voltage: 2.5V – 6.0V DC.

• Interface: I2C (Address 0x48 default).

• Resolution: 8-Bit (0-255 steps).

• Inputs: 4x Analogue Input Channels (AIN0 - AIN3).

• Outputs: 1x Analogue Output Channel (AOUT).

• Onboard Peripherals (Jumper Selectable):

  • Thermistor (Temperature Sensor).

  • Photoresistor (Light Sensor).

  • Potentiometer (Voltage Divider).

• Indicators: Power LED & DAC Output Brightness LED.

• Dimensions: 36mm x 23mm.

Quality Advantage & Differentiation: Why choose this specific module? Unlike bare chips, this breakout board is a self-contained "Analogue Lab."

1. Built-in Diagnostics: The onboard Green LED connected to the DAC output provides instant visual feedback—as you increase the voltage via code, the LED gets brighter, confirming your code is working without needing an oscilloscope.

2. Flexible Learning: The three onboard sensors (Light, Temp, Voltage) are connected via removable jumpers (P4, P5, P6). This allows beginners to learn ADC coding instantly, while advanced users can remove the jumpers to use the pins for their own external sensors.

Key Applications & Usage

• Raspberry Pi Analogue Expansion: Give your digital-only Raspberry Pi the ability to read joysticks, temperature sensors, and potentiometers.

• ESP8266/ESP32 Expansion: Expand the single analogue pin on an ESP8266 to four robust channels.

• Waveform Generation: Use the DAC output to generate sine, triangle, or sawtooth waves for signal testing or audio experiments.

• Sensor Data Logging: Monitor up to 4 analogue voltages simultaneously via I2C.

What's Included & Required

• Included: 1x PCF8591 AD/DA Module, 1x Set of Female-Female Jumper Wires (4-pin).

• Required: Microcontroller (Arduino, Raspberry Pi, ESP32) and I2C Library (e.g., Adafruit_PCF8591).

Helpful Tutorials & Resources

• Arduino Tutorial: Lesson 10: PCF8591 ADC/DAC with Arduino - Comprehensive guide on reading inputs and writing to the DAC.

• Raspberry Pi Guide: Interfacing PCF8591 with Raspberry Pi - Python-based tutorial for reading analogue sensors.

• Video Demo: How to Interface PCF8591 - Visual walkthrough of the wiring and code.

The "Virtual Technician" Support Panel

• ⚠️ CRITICAL SETUP WARNING:

  • Jumper Conflict: The board comes with jumpers P4, P5, and P6 installed by default. These connect the onboard Thermistor, LDR, and Potentiometer to the Analogue Input pins.

  • Action Required: If you want to connect EXTERNAL sensors to pins AIN0, AIN1, or AIN3, you MUST REMOVE the corresponding red jumpers (P4/P5/P6). Failing to do so will mix the onboard sensor signals with your external signals, resulting in incorrect data.

• Pinout Reference:

  • Left Header (Analogue I/O):

    • AOUT: Analogue Voltage Output (DAC).

    • AIN0 - AIN3: Analogue Inputs 0-3.

  • Right Header (Power/Data):

    • VCC: 2.5V - 6V Power.

    • GND: Ground.

    • SDA: I2C Data.

    • SCL: I2C Clock.

• Troubleshooting: Readings stuck or jittery? Typically, the I2C address is fixed at 0x48 on these modules. Ensure your code uses this address. Also, if reading AIN0/1/3 seems inaccurate, check if the black jumpers are still installed!