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.
A one-time colleague of mine recently put me onto Tailscale, a rather nifty product that allows you to wrangle all of your computers, phones and more into a single, secure and Internet-spanning virtual private network (VPN). I decided to give it a try and I’m very impressed with its performance and ease-of-use — the latter very important for someone like me who’s not a network guru.
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.
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.
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.