This project explores how an Arduino can coordinate three low-voltage waveform outputs separated by 120 degrees. A DAC converts each digital sample into an analog voltage; it does not provide the power stage needed to drive a motor or other load.

How the three phases relate

A balanced three-phase set uses the same frequency and amplitude for all outputs, with phase offsets of 0°, 120° and 240°. The controller updates each output from a sine lookup table or calculated sample sequence. Output quality depends on the update rate, DAC resolution, filtering and timing stability.

Hardware and I²C checks

The example concept uses an Arduino and MCP4725 digital-to-analog converters. Before wiring multiple converters to one I²C bus, check the exact chip variant and module documentation: identical I²C addresses cannot share the bus as separate devices. Use modules with distinct supported addresses or an I²C multiplexer, and confirm every device acknowledges before generating samples. See the Microchip MCP4725 datasheet and Adafruit's Arduino guide.

Bring-up and measurement

1. Verify the board, DAC supply voltage and I²C addresses against their datasheets.
2. Test one DAC output first, then confirm the three phase offsets with an oscilloscope.
3. Check amplitude, frequency, sample timing and waveform distortion before connecting downstream circuitry.

Safety: These DAC outputs are low-power signal sources. Do not connect them directly to mains, a motor or a high-power load. A separate, properly designed and isolated power stage is required for load control.

Design takeaway

This setup is useful for studying phase relationships and low-voltage signal generation. Treat address selection, timing and measurement as part of the design, and validate the actual hardware before relying on the output.