I’d like to introduce you to Depot, the new name for an expanded version of the Raspberry Pi RP2040-based adaptor I launched last year as cli2c. Why the name change? In addition to I²C, the firmware and the client-side code that interacts with it, now supports 1-Wire, and more buses will be supported soon.
The Raspberry Pi company released version 1.5.0 of the Pico SDK a week ago — right after I issued the latest version of my desktop computer-oriented I²C adaptor, which is based on the Pico’s RP2040 chip. If I’d have known about the SDK update, I would have held back — SDK 1.5.0 solves an irritating problem I’d faced with unexplained adaptor firmware hangs.
I haven’t been using a Picoprobe for a while because I needed to rebuild mine and issues with the code’s dependencies and a lack of updates from the Raspberry Pi Foundation meant I haven’t been able to get it to work properly. But I did spot this doohickey: a PCB you can solder a Pico and a header. It’s a much neater way to assemble a Picoprobe than breadboard and jumper wires.
Here’s a very useful technique if you’re working on a CircuitPython program that you need to store data on the host microcontroller’s Flash — and to continue to be able to mount and access the device from your computer. I’ve used it with a Raspberry Pi RP2040-based board, but it should work with other CircuitPython devices too.
macOS 13.0.0 Ventura introduced an irritating problem for all us Mac-based Raspberry Pi Pico programmers: Finder no longer allows you to copy .uf2 files to a mounted Pico. It’s not a forbidden operation, but it does trigger an error that prevents the copy from taking place. This is undoubtedly the ‘new normal’, so here are some ways to circumvent the error. I’ll save the best one until last.
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:
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.
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.
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.
My Raspberry Pi Pico-based Motorola 6809 emulator uses the RP2040’s built-in serial-over-USB functionality to receive machine code sent from a host computer. The 6809 and its support code is written in C, but can you make use of the same process under Python? Yes, you can, and here’s an easy way to do it.
smittytone messes with micros 