make sure you have a backup of your previous version!

Why am I mention this now? Well ...

Yesterday I reserved some time, to prepare the instructions on how to compile grblHAL for the Raspberry Pi Pico CNC Shield. Everything went fine, I do have downloaded the latest source code, made the required modifications, compiled everything and at the end I finished writing the instructions. Even so I used this time my Linux machine, I had no trouble ... until I  run the exact G-Code, from the initial test, with the newly build firmware ... a new error:24 (or was it 23?). basically the same setup like a few days back, with "only" the firmware been changed ... Shit.

Anyhow, I do have to check the previous firmware. If needed, I would have to compare the different source code versions. bla bla bla ...

Even if I would have compiled everything on my Windows box, which I had used for the initial firmware version, I would still have the previous version. As I do the following, when "updating" the source code with the latest changed from Github. (Might be old-school, but that's how I do it)

--- to make it clear ... always downloading the complete source code is not the ideal way; better create a local backup and just download the new and updated files --- 

mkdir <current date>
cd <newly created directory>
git clone -b master https://github.com/raspberrypi/pico-sdk.git
cd pico-sdk
git submodule update --init
mkdir build
cd build
cmake ..
cd ..
cd ..
git clone -b master https://github.com/raspberrypi/pico-examples.git
git clone --recurse-submodules https://github.com/grblHAL/RP2040.git
cd RP2040
git pull --recurse-submodules
cd ..