This is just a quick post while I'm working on something bigger. I've tried to get a NodeMCU module to interface to the serial port on my CTC Dual/Bizer printer, which uses a Rev G(?) Mightboard motherboard. Unfortunately, the main serial port is not exposed, just UART1. The easiest way I've found to get to the TX/RX lines was to piggyback on the resistors just before the ATMega8U chip: The 8U is used as a serial to USB converter. 5V and ground can be picked up from the exposed UART header, pictured bottom middle: I tried to use the ESP3D firmware but it only works with boards that support G-Code, not X3G. So I abandoned the project due to lack of time. The pictures above are from a few weeks ago but just yesterday I managed to put a hole in my 8U chip, no idea how that happened: So now I was forced to use my makeshift serial connection. I tried both possible solutions: https://github.com/beckdac/ESP8266-transparent-bridge https://github.com/jee...
Electronics and programming interspersed at various levels of difficulty.