Pico

Les Pounder’s drawers are full of old tech. No, he’s not smuggling technology, but he is reusing it in this project!

CIRCUITPY THON

Credit: http://circuitpython.org

OUR EXPERT

Les Pounder is associate editor at Tom’s Hardware and a maker for hire. He blogs about his adventures and projects at http://bigl.es.

YOU NEED

Pi Pico

PIR sensor (obstacle sensor)

Breadboard

Jumper wires to connect

Pico to PIR

Android device

Pico-to- Android cable

Code: https:// github.com/ lesp/LXF 309-Circuit Python-USB- Camera- Trigger/ archive/refs/ heads/main. zip

We’ve all got a spare smartphone lurking in a drawer. Some of these devices will gather dust and then get recycled. But what if we could reuse them?

In this project, we’re reusing an old phone with a Raspberry Pi Pico-powered camera trigger. Using a PIR (passive infrared) sensor, we will detect movement and use that to trigger the camera to take a photo. The Pi Pico is running CircuitPython and is acting as an emulated USB keyboard. Trigger the sensor, and the ‘keyboard’ presses Enter and takes a photo.

Pick a Pico

There’s a plethora of Pico-compatible boards on the market. There are boards from Raspberry Pi, Pimoroni, Adafruit, Waveshare, Sparkfun and a few clones from Aliexpress. We chose Seeed’s XIAO RP2040 board. It is much smaller than a Raspberry Pi Pico and it has fewer GPIO pins, but the most important thing is that it has USB C. Our Android device also has USB C, and that means we only need a USB C cable to connect the pair. The Android device will power the XIAO RP2040, and present itself as a USB keyboard. If you only have a Raspberry Pi Pico, you need to use a series of adapters to convert USB A to USB C.