Adapterboard to use cheap (7€) Mach3 CNC Breakout Board with Bluepill/Blackpill You can find it at Aliexpress, search for "MACH3 Engraving machine 5 Axis CNC Breakout Board With Optical Coupler" or similar.
I want to use it with 3 Axis millingmachine and grblHAL. https://github.com/terjeio/grblHAL
This is not tested, PCB is ordered 14.01.2021
new version V2, because 5V supply for MACH3 Interfaceboard are necessary. Powersupply is now 12-24V for Bluepill_Mach3 Interface and MACH3 Interfaceboard.
18.01.2021