“If you’ve been reading this blog for a long time, you’ll know that my first Raspberry Pi project was a version of a Star Trek Tricorder. The first version was made out of LEGO and used a Pi in combination with an Arduino Leonardo clone.
It was rather large, it didn’t do a LOT but I liked it and it taught me so much. It also started my unhealthy obsession with sensors!
Flash forward nine years from the original conception (!). I have since moved on with the project to using more sensors, better enclosures and exploring battery power.
The arrival of the Pico
This year, the Raspberry Pi Pico was launched. This was the first Raspberry Pi microcontroller (featuring their own silicon, no less!) and it immediately made me think of my old project. Could this be the low-power device I was looking for? Could this device which didn’t have the boot-up time of the regular Raspberry Pi and with no SD card to corrupt, be the thing that I had been looking for?
Getting the kit together
I wanted to just check that I could use everything that I wanted to use in the latest iteration of the Picorder. In nine years, sensors have become more widely available, more complex and there were a lot more types to choose from. I settled on the following components:
1 x Raspberry Pi Pico (this one from The Pi Hut)
1 x piece of 160x100mm stripboard
Various male and female pin headers (anywhere I could find them)
Lots of female-to-female jumper cables (anywhere I could find them)
1 x BME680 air quality sensor (Pimoroni Breakout Garden)
1 x VEML6075 UVA/UVB sensor (Pimoroni Breakout Garden)
1 x 11×7 Matrix (Pimoroni Breakout Garden)
1 x BMP280 atmospheric sensor (cheap Chinese version from AliExpress)
1 x AMG8833 thermal sensor (Adafruit, but from Pimoroni)
1 x Ultimate GPS Breakout v3 (Adafruit, but from Pimoroni)
1 x MAX98357A I2S mono amp (Adafruit, but from The Pi Hut)
1 x small 3W speaker (Pimoroni)
1 x 2.8″ TFT LCD Breakout with resistive touchscreen (Adafruit, but from The Pi Hut)
1 x STMPE610 Resistive Touchscreen Controller (Adafruit, but from The Pi Hut)
Why these components? In one word: quality.
Both Adafruit and Pimoroni products are very high quality (and they’re not cheap!) and they have a lot of support available in terms of tutorials and libraries. For the Adafruit products, there is one trade-off – you need to use their fork of MicroPython (called CircuitPython) in order to get the most out of their support material. More on this decision later! For the Pimoroni products, I just had to make sure that there were Adafruit CircuitPython libraries available for the bare components – which there are!
For some of the sensors (as you can see), I chose to use components from the Pimoroni Breakout Garden series. I already had some of them, but mostly I chose them as they offer the smallest form-factors out there for sensors of those particular types. For the GPS, I did consider the Breakout Garden PA1010D sensor, but as I already had the Adafruit Ultimate GPS board, I thought I’d save some pennies! First time for everything… 😉”