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
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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
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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.

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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
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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.

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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
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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
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Fun with FreeRTOS and the Pi Pico: timers

I made use of FreeRTOS’ timer functionality in the most recent post in this series, but I didn’t go into detail because the post was focused on other features. It’s time to address that deficiency. Today I’m talking about timers.

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Notarise macOS command line apps more quickly

It’s June once more, and time for Apple’s Worldwide Developers’ Conference (WWDC). This is a chance to learn about new functionality and, yes, discover initiatives announced at previous WWDCs that you completely missed the first time around. A case in point: Apple’s revamp of how apps are notarised at the command line, which was revealed at WWDC 21 but I only encountered this week.

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How to write Unix man pages for macOS command line apps

Over the last few years I’ve released a number of command line utilities for macOS. I’ve always included online help within them, triggered with the --help switch, but I recently wondered how I might provide Unix Manual pages too. It would allow users to call up help with the CLI command man as well as a command switch. Belts and braces, perhaps, but I’m a completist and, more to the point, didn’t know how it was done and wanted to learn.

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