HackSpace Magazine Issue 64 – Soldering Irons on Test discusses how to get fast analog reads from a Raspberry Pi Pico in CircuitPython.

CircuitPython is great for getting started with microcontroller programming, but it can have a
few shortfalls. One of which is very accurate timing. The CircuitPython interpreter does quite a bit in the background, and this means that the execution of the program pauses occasionally. These pauses are short and don’t generally cause any problems, unless you need something to be very accurate time-wise.

One thing you might need accurate timing for is reading an analogue signal. If you want to
understand what the signal is doing, you need to know exactly when the readings are taken.

Thankfully, in CircuitPython 8 on Raspberry Pi Pico, there’s a solution – analogbufio. This lets you read values from the analogue-to-digital converter (ADC) directly into a Python data structure. It’s only available on Pico and other RP2040-based hardware at the moment, but may be expanded to other platforms in the future.

Read more (pages 82-83), download PDF, buy now, subscribe.