I am currently building a tiny 4in1 Blheli_s ESC for a micro brushless copter. The final design will be 20x20mm, run blheli_s, support 1S @4A, and will probably weight less than two grams. In order to verify my hardware design i soldered a breadboard version of my circuit and started to port the blheli_s code to my setup.
It turned out that there is no native Linux driver for the Silabs toolstick i bought recently -- DOH! Lucky for us there is a factory bootloader in all newer EFM8 devices and SiLabs published its protocol. Too bad there was no bootloader upload script that worked under Linux. I had to fix that by writing my own implementation. See blog post about it for more details.
In order to run blheli_s on my custom 1S board i needed to change some defines. However after flashing i struggled to get it to commutate my test motors. As it turned out i needed to invert the motor phase measurements for my setup (thanks sskaug for your help!). With this beeing fixed i could spin a test motor for the very first time:
Yay! The startup is not tuned yet and the motor is completely unsuitable for 1S operation (too low KV and to heavy) but the principle is working. Stay tuned for more 😉