Dave Akerman may well have set a record for the highest-flying Raspberry Pi Pico, after attaching the new microcontroller to a high-altitude weather balloon to gather data and track its course.
"My main hobby is flying weather balloons, using GPS/radio trackers to relay their position to the ground, so they can be tracked and hopefully recovered," Akerman writes in a piece for the Raspberry Pi Blog. "Trackers minimally consist of a GPS receiver feeding the current position to a small computer, which in turn controls a radio transmitter to send that position to the ground. That position is then fed to a live map to aid chasing and recovering the flight."
Traditionally, Akerman's trackers would be based on an Arduino microcontroller — but the Raspberry Pi Pico, launched late last month as the first device powered by the Raspberry Pi RP2040 microcontroller, proved a tempting replacement.
"It has plenty of I/O — SPI ports, I2C and serial all available — plus a unique ability (not that I need it for now) to add extra peripherals using the programmable PIO modules, so there was no doubt that it would be very usable," Akerman explains. "Also, having much more memory than typical microcontrollers, it offers the ability to add functions that would normally need a full Raspberry Pi board — for example on-board landing prediction."
Akerman paired a Raspberry Pi Pico with a u-blox GPS receiver, LoRa radio transceiver, and an I2C environmental sensor, plus software written in C — ported directly from earlier Arduino and Raspberry Pi powered balloon trackers. "Typical Arduino boards don’t have enough memory to store the measured wind data," Ackerman notes, "but the Raspberry Pi Pico has more than enough."
Akerman's full write-up is now available on the Raspberry Pi Blog.