The BBC Micro:bit
For younger students, we use BBC Micro:bit to introduce them to programming and connecting the physical inputs and outputs needed with embedded systems. We do this mainly based on the learning resources we have access to, which generally target younger students. Otherwise, the BBC Micro:bit is very comparable to the Circuit Playground Express.
The Circuit Playground Express (CPX)
The reason we use the CPX for years 9-10 is because Adafruit provides such good support via MakeCode , CircuitPython and their own learning system. Their projects are also a little more advanced and challenging.
From Blocks to Text