Adafruit GP8403 I2C DAC with 12V Booster

0-10V analog voltages!

by Liz Clark

published August 27, 2026, last edited August 27, 2026

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Product guide

Arduino

Using the GP8403 breakout with Arduino involves wiring up the breakout to your Arduino-compatible microcontroller, installing the Adafruit_GP8403 library, and running the provided example code.

Wiring

Wire as shown for a 5V board like an Uno. If you are using a 3V board, like an Adafruit Feather, wire the board's 3V pin to the breakout VIN.

Here is an Adafruit Metro wired up to the breakout using the STEMMA QT connector:

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

The signal will be output from the DAC V0 terminal block with GND.

Here is an Adafruit Metro wired up using a solderless breadboard:

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

The signal will be output from the DAC OUT0 pin and GND.

Library Installation

You can install the Adafruit_GP8403 library for Arduino using the Library Manager in the Arduino IDE.

Click the Manage Libraries ... menu item, search for Adafruit_GP8403, and select the Adafruit GP8403 library:

If asked about dependencies, click "Install all".

If the "Dependencies" window does not come up, then you already have the dependencies installed.

If the dependencies are already installed, you must make sure you update them through the Arduino Library Manager before loading the example!

Example Code

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/*
 * Adafruit GP8403 Dual Output 5 V Example
 *
 * Selects the 0-5 V range and sets both output channels.
 */

#include <Adafruit_GP8403.h>

Adafruit_GP8403 gp8403;

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10);
  }
  Serial.println("Adafruit GP8403 Dual Output 5 V Example");

  if (!gp8403.begin()) {
    Serial.println("Could not find GP8403");
    while (1) {
      delay(10);
    }
  }

  if (!gp8403.setOutputRange(GP8403_RANGE_5V)) {
    Serial.println("Could not select the 5 V output range");
    while (1) {
      delay(10);
    }
  }

  if (!gp8403.setVoltages(1.25, 3.75)) {
    Serial.println("Could not set both output voltages");
    while (1) {
      delay(10);
    }
  }

  // getVoltage() returns cached values, not hardware readback.
  Serial.print("Channel 0: ");
  Serial.print(gp8403.getVoltage(0), 2);
  Serial.println(" V");
  Serial.print("Channel 1: ");
  Serial.print(gp8403.getVoltage(1), 2);
  Serial.println(" V");
}

void loop() { delay(1000); }

/*
 * Adafruit GP8403 Dual Output 5 V Example
 *
 * Selects the 0-5 V range and sets both output channels.
 */

#include <Adafruit_GP8403.h>

Adafruit_GP8403 gp8403;

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10);
  }
  Serial.println("Adafruit GP8403 Dual Output 5 V Example");

  if (!gp8403.begin()) {
    Serial.println("Could not find GP8403");
    while (1) {
      delay(10);
    }
  }

  if (!gp8403.setOutputRange(GP8403_RANGE_5V)) {
    Serial.println("Could not select the 5 V output range");
    while (1) {
      delay(10);
    }
  }

  if (!gp8403.setVoltages(1.25, 3.75)) {
    Serial.println("Could not set both output voltages");
    while (1) {
      delay(10);
    }
  }

  // getVoltage() returns cached values, not hardware readback.
  Serial.print("Channel 0: ");
  Serial.print(gp8403.getVoltage(0), 2);
  Serial.println(" V");
  Serial.print("Channel 1: ");
  Serial.print(gp8403.getVoltage(1), 2);
  Serial.println(" V");
}

void loop() { delay(1000); }

View on GitHub

Upload the sketch to your board and open up the Serial Monitor (Tools -> Serial Monitor) at 115200 baud. You'll see the GP8403 recognized over I2C.

If you connect the DAC output to a multimeter or scope, you will be able to measure 1.25V on output 0 and 3.75V on output 1 +/-0.2%.

Page last edited August 27, 2026