My nephew wished to get a toy signal for his toy cars in his toy city. I think that is a nice challenge, and today, I have time to continue the prototyping.

It is always funny how chaotic a circuit looks on a breadboard. But what matters is that the circuit starts to work. Later, when all values are defined, I plan to move it to a small PCB.

It uses a ATtiny13 microcontroler. Decades-old technology, as I taught myself how to program them when I was still in school. Of course, I program it in assembly, which is the most fun for small programs. I still enjoy a rather old software version of the development system, as it has a very nice build simulator where you can watch the CPU and the IO register while the code runs. Over the years, this has taught me how a computer “thinks” on the register level.

What is your favorite microcontroller family, and have you gone to assembly for some special purpose?