Raspberry Pi Pico W as a Sensor Node

The Pico W at $6 is an impressive value proposition for a WiFi sensor node. Here's my experience after deploying six of them.

MicroPython on the Pico W has a solid WiFi stack but it has one serious quirk: the CYW43 WiFi chip shares the SPI bus with the on-board LED, so you can't toggle the LED while a WiFi operation is in progress without a small delay. In practice, just don't use the LED while WiFi is active and you'll be fine.

Power consumption in light sleep is around 2mA, which is 3-4x worse than a bare ESP32 in comparable sleep states. If battery life is critical, the ESP32 with aggressive deep sleep wins. For mains-powered sensors the Pico W is excellent — cheap, easy to program, good community support, and the RP2040's dual-core architecture handles sensor reading and WiFi communication in parallel very cleanly.