Let's generate an analog signal!

Well, don't get too excited. There's only a single DAC and it's a whopping 5 bits! So don't expect super awesome high fidelity audio block rockin' beats or anything.

Here's a simple sine wave generator you can try:

Download: file
import time
import math
import board
from analogio import AnalogOut

dac = AnalogOut(board.G3)

while True:
    dac.value = int((2**16 - 1) * (0.5 + 0.5 * math.sin(time.monotonic()*10)))

Save that as something like dac.py and run it with:

Download: file
python3 dac.py

And connect the G3 pin to an oscilloscope. You should see something like this:

Note that even though the MCP221's DAC is only 5 bits, you set it using a 16 bit value to comply with the CircuitPython API.

This guide was first published on Dec 22, 2019. It was last updated on Dec 22, 2019. This page (DAC) was last updated on Feb 19, 2020.