How to talk to I2C sensors, displays from… Linux

T’other week, I wrote about my work on building a Raspberry Pi RP2040-based I²C host device and some macOS client software to control it. I mentioned that I might get the latter running under Linux too. I now have, and it does.

The matrix display client and the CPU activity display example running on a Raspberry Pi 400
The matrix display client and the CPU activity display example running on a Raspberry Pi 400
Continue reading

Review: Kitronic Pico Pin Breakout 👍🏻

A short post, this, to recommend Kitronic’s Pico Pin Breakout: an add-on that makes it really easy to make sure you’re wiring up a Raspberry Pi Pico’s pins correctly. It looks like this:

The Kitronics Pico Pin Breakout makes all the Pico's pins highly visible
Continue reading

How to talk to I2C sensors, displays from a Mac

This post was originally going to be about building a tool to access I²C devices on a Mac, reaching them via USB and an Excamera Labs I2CMini adaptor board. But then I accidentally snapped the pins and board traces off my I2CMini, so I had to go back to the drawing board. Now it’s about accessing I²C devices on a Mac using a Raspberry Pi Pico, or any other RP2040-based board, as the adaptor.

An I2C matrix display showing my Mac's CPU utilisation graphically
I2C antics: a CPU utilisation readout using an RP2040-based board as an I2C bridge to a matrix LED
Continue reading

Preview JSON files with macOS’ QuickLook and PreviewJson

I’m pleased to announce the latest in my PreviewApps series: PreviewJson. It taps into macOS’ QuickLook feature to provide at-a-tap previews of JSON files and generates Finder icon thumbnails for them too. There are some updates out too.

Now available from the Mac App Store: PreviewJson
Continue reading

How to manage multiple serial devices on a Mac

I connect to my Mac many USB devices that communicate over a serial (UART) bus to send debug information to the host or to receive data and code. You know, Raspberry Pi Picos, Adafruit Feathers, FTDI cables — that kind of thing. Often I have more than one connected. Is there an easy way to see what’s connected without listing /dev every time and to remember connected devices’ paths?

A USB serial device attached to my Mac
Continue reading

ARM Assembly on the Pi Pico: Stack attack

This time round, I’ll wrap up my coverage of the key ARMv6-M Thumb instructions and mnemonics that you can use to command the Raspberry Pi RP2040. There are not many instructions left that were not covered in parts one and two, and I won’t be including all the remaining mnemonics, only those you’re likely to use frequently.

Continue reading

The Golden Age of Wireless: Adopting Raspberry Pi’s Pico W

I was travelling when the Raspberry Pi Foundation launched the Pico W, so I had to wait to get back before I could get my hands on one. I have one now, and to try it out, I decided to port my network-oriented PicoWeather app, this time creating a MicroPython version — it was released for CircuitPython.

Raspberry Pi Pico WiFi IoT Device remade with the Pico W
Continue reading

Arm Assembly on the Pi Pico: Mnemonics #2

A number of the Cortex-M0+ Thumb ops I covered last time update the core’s Program Status Register (PSR) based on the outcome of the operation. The ops that do so have an S appended to their mnemonics and they only work with the core’s ‘low’ registers, R0-7.

Continue reading

ARM Assembly on the Pi Pico: Mnemonics #1

Last time, I covered the basics of doing ARM assembly programming on the Raspberry Pi Pico’s RP2040 microcontroller. Now it’s time to get to grips with the dozens of instructions to which the RP2040’s Cortex-M0+ cores respond.

ARM assembly instructions for the Raspberry Pi Pico's RP2040 chip
Continue reading

Get Started with ARM Assembly on the Pi Pico

When I got my first microcomputer, I already knew Basic programming. My machine had a different Basic dialect from the one I’d learned at school, and there was a stack of graphics and sound functionality to get to grips with too, but it wasn’t long before I felt I’d mastered the high-level stuff and that it was time to move on to machine code. That’s how I’ve come to feel about the Raspberry Pi Pico’s RP2040 chip. The time’s right to learn ARM assembly programming on the Pico.

The Raspberry Pi RP2040 chip
Continue reading