There were a few questions in the forum about generating sine waves on the MCP4725 I2C DAC. To show one way you might accomplish this, an example sketch was added to the Adafruit MCP4725 library. You can set the resolution between 9-bit and 5-bit, depending on your requirements and how much flash space you can spare. 5 and 6-bit output would benefit from a basic filter to smooth the output out, but 7-bits and higher is reasonably smooth, as can be seen in the image above comparing the out from an Agilent function generator (in blue) and the MCP4725 sketch at 8-bit resolution (in yellow).
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.