7Semi MCP4725 Arduino Library

Arduino driver for the Microchip MCP4725 12-bit DAC.

The MCP4725 provides a high-resolution analog voltage output using a digital I²C interface, making it ideal for signal generation, calibration, and analog control applications.

Features

• 12-bit DAC output (0–4095)

• Fast mode

• EEPROM write mode

• Power-down modes support

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Connections / Wiring

The MCP4725 communicates using I²C interface.

I²C Connection

MCP4725 Pin	MCU Pin	Notes
VCC	3.3V / 5V	Supply voltage
GND	GND	Common ground
SDA	SDA	I²C data
SCL	SCL	I²C clock
A0	GND / VCC	Address select

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I²C Notes

• Default I²C address: 0x62

• Supported bus speeds:

  • 100 kHz
  • 400 kHz (recommended)

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Installation

• Arduino Library Manager

  1. Open Arduino IDE
  2. Go to Library Manager
  3. Search for 7Semi MCP4725
  4. Click Install

• Manual Installation

  1. Download this repository as ZIP
  2. Arduino IDE → Sketch → Include Library → Add .ZIP Library

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Library Overview

Setting Voltage

dac.setVoltage(2.5);

• Sets DAC output in volts

Setting Raw DAC Value

dac.setAnalogOut(2048);

• Range: 0 → 4095

Getting Output Voltage

float voltage;

dac.getVoltage(voltage);

• Returns current output voltage

Setting Reference Voltage

dac.setVRef(3.3);

• Must match actual supply voltage for accuracy

DAC Mode Selection

uint64_t serial;

dac.setMode(MCP4725_FAST_MODE);

• MCP4725_FAST_MODE → Fast update (volatile)
• MCP4725_WRITE_DAC_EEPROM → Persistent output

EEPROM Operations

uint16_t value;

dac.readEEPROM(value);

Reads stored DAC value

uint16_t value;

dac.readEEPROM(value);

Power-down Modes

dac.setPowerDown(1);

• 0 → Normal operation
• 1 → 1kΩ pull-down
• 2 → 100kΩ pull-down
• 3 → 500kΩ pull-down