Adafruit's PiCowbell Adalogger Turns a Raspberry Pi Pico or Pico W Into a Compact Datalogger
With a battery-backed real-time clock and microSD storage, this compact board has everything you need for easy data logging.
Adafruit has launched an add-on for the Raspberry Pi Pico or Pico W, designed to turn it into a fully-fledged data logger with local storage and easy expansion — and it's called it the PiCowbell Adalogger.
Designed to connect to the underside of a Raspberry Pi Pico or Pico W board — or any other development board which shares the pinout and physical dimensions — the Adafruit PiCowbell Adalogger includes features specifically for data logging. At the heart of the board is a CR1220 button cell battery holder, though this isn't used to power the Raspberry Pi Pico; instead, it drives a real-time clock (RTC), keeping accurate time even when external power is removed.
Elsewhere on the board is a right-angled STEMMA QT connector for external I2C devices, a microSD slot for local data storage, and a physical reset button. Most pins are doubled in the layout, which Adafruit says is handy for solder-jumpering — and while there's no on-board wireless connectivity, dataloggers built with the PiCowbell Adalogger can easily make use of the Wi-Fi and Bluetooth radio built into the Raspberry Pi Pico W.
The board is the second in the PiCowbell range, though unlikely to be the last — preceded by the simpler PiCowbell Proto, which added prototyping space, a physical reset button, and a STEMMA QT connector for solder-free expansion. In both cases, the boards support multiple mounting options — including with stacking headers so the resulting sandwich is still breadboard-compatible, with socket headers so the two can be separated easily after use, and direct soldering. "Of course, this is very compact and inexpensive," Adafruit notes, "but you won't be able to remove the PiCowbell."
The PiCowbell Adalogger is currently listed on the Adafruit store at $7.95, though at the time of writing was showing as out-of-stock. More information is available in the company's tutorial on its use.