MCP4725 I²C DAC Sine Generator

A 12-bit DAC on the I²C bus turns an Arduino into a function generator — pump out clean sines, ramps, or arbitrary waveforms.

Difficulty: Breadboard. Estimated build time: about 45 minutes. Estimated parts cost: about US$3.80. 4-part bill of materials with live supplier pricing. A simple function generator built around the MCP4725, a single-channel 12-bit DAC with an I²C interface.