Running 57 threads at once on the Arduino Uno
When one thinks of the Arduino Uno, one thinks of a capable 8-bit microcontroller platform that nonetheless doesn’t set the world alight with its performance. Unlike more modern parts like the ESP32, it has just a single core and no real multitasking abilities. But what if one wanted to run many threads on an Uno all at once? Adam whipped up some code to do just that.
Threads are useful for when you have multiple jobs that need to be done at the same time without interfering with each other. The magic of Adam’s ThreadHandler library is that it’s designed to run many threads and do so in real time, with priority management as well.
On the Arduino Uno, certainly no speed demon, it can run up to 57 threads concurrently at 6ms intervals with a minumum timing error of 556 µs and a maximum of 952 µs. With a more reasonable number of 7 threads, the minimum error drops to just 120 µs. Each thread comes with an estimated overhead of 1.3% CPU load and 26 bytes of RAM usage.
While we struggle to think of what we could do with more than a handful of threads on an Arduino Uno, we’re sure you might have some ideas – sound off in the comments. ThreadHandler is available for your perusal here, and runs on SAMD21 boards as well as any AVR-based boards that are compatible with TimerOne. We’ve seen other work in the same space before, such as ChibiOS for the Arduino platform.
If you're interested in making your own version, PMD Way has you covered with a huge range of parts including Arduino Uno compatible boards and more.