This board consists of a STC15W104W microcontroller and a CH340G USB interface. Print is marked: CJMCU-104 found on ebay, ali-express etc This repository holds:
- The reverse-engineered schematic.
- A tiny demo project.
Needs a drop of solder to connect all 2 or 3 solder islands in the corner of the pcb either on the 3.3V or 5V to select the voltage before using it.
- SDCC (free to use compiler w/o any limits like keil)
- AtmelStudio 7 (not needed, but has integrated environment, editor, C beautyfier, tools like make, etc...)
- stc-isp-15xx-v6.88.exe (to program the STC processor)
Compiler/Linker SDCC: http://sdcc.sourceforge.net/
Programming software to download into STC processor: http://www.stcmicro.com/rjxz.html
To understand the hidden connections, removed the crystal:
And drawn the two connections between the usb and processor parts of the board.
