I second advice to focus on embedded systems, but I'd stay away from raspberry pi. I'd much prefer something you could debug easily from outside. There are plen

I second advice to focus on embedded systems, but I'd stay away from raspberry pi. I'd much prefer something you could debug easily from outside. There are plenty of arm chips one can debug with openocd and gdb. Sometimes being able to debug a running kernel from the outside can make a huge difference when troubleshooting. If also choose some class of device and get to know it. Many Linux drivers are very similar across a class of devices. For example CSI cameras on top of V4L. Thankfully the code in the Linux kernel is very readable. Also it is well documented online. I definitely recommend a good ide too.