Have you considered gnupth, a venerable, solid light-thread library ? I've never used it on a microcontroller and if you work from interrupts you might need to

Have you considered gnupth, a venerable, solid light-thread library ? I've never used it on a microcontroller and if you work from interrupts you might need to adapt its event loop, but that's still probably the first lib I would try, having successfully used it in large industrial projects in the past. Actually, there were no release since 2006, when the last bug was fixed I guess :+) https://www.gnu.org/software/pth/ https://www.gnu.org/software/pth/