I own a JL1N-20MR (supposedly FX1N-20MR clone) based on STM32F103RCT6 CPU.
I figured that I might be able to re purpose this PLC for home automation by altering it's firmware to use something more IOT oriented. Do this instead of creating my own hardware design since this board has everything I need.
I don't have experience in hardware reverse engineering, nor in programming STM32. However I am experienced programmer with reasonable understanding of electronics. I did a number of successful embedded hardware/software projects in the past.
I am searching for hardware documentation or anything that could help me start working with this board.
Best Answer
Thees are my findings:
CPU STM32F103RCT6
Input voltage seems to work without problems from 12v-24v. Has onboard 5v and 3.2v regulators.
I was able to program the board with
stm32loader
. I was able to build working firmware using STM32Cube but sadly had 0 success with PlatformIO.