Wiring up the MCP4725 breakout PCB is super easy. To start, we'll attach the breakout headers so we can plug it into a breadboard.

Break off a strip of 6-pins of 0.1" male header and stick the LONG pins down into a breadboard
Break off a strip of 6-pins of 0.1" male header and stick the LONG pins down into a breadboard
Place the breakout board on top so the short ends of the header stick up through the pads
Solder each pin using a soldering iron and solder, to make solid connection on each pin.

This part is not optional! You cannot 'press fit' the header on, it must be attached permanently

Now that the header is attached, we can wire it up. We'll demonstrate using an Arduino.

FIrst, connect VDD (power) to a 3-5V power supply, and GND to ground.

The DAC uses I2C, a two-pin interface that can have up to 127 unique sensors attached (each must have a different ADDRESS).

  • SDA to I2C Data (on the Uno, this is A4 on the Mega it is 20 and on the Leonardo digital 2)
  • SCL  to I2C Clock(on the Uno, this is A5 on the Mega it is 21 and on the Leonardo digital 3)
There's two other pins remaining.

  • A0 allow you to change the I2C address. By default (nothing attached to A0) the address is hex 0x62. If A0 is connected to VDD the address is 0x63. This lets you have two DAC boards connected to the same SDA/SCL I2C bus pins.
  • VOUT is the voltage out from the DAC! The voltage will range from 0V (when the DAC value is 0) to VDD (when the DAC 'value' is the max 12-bit number: 0xFFF)

This guide was first published on Sep 05, 2012. It was last updated on Sep 05, 2012.

This page (Wiring) was last updated on Nov 27, 2020.