What's really happening here: the ESP32 received via WiFi the order to send GCode tones to the 3DPrinter's serial interface via the USB Host.

The main idea of this project was suggested by @iHayri1 when he expressed the need to be able to write on the SD Card of the 3DPrinter without actually ejecting it.

In this demo the ESP32 is sending real time GCode to the printer, and it's only a matter of sending three extra GCode commands to get it written on the SD.

Credits:

• https://github.com/tomorrow56/M5Stack_USB_Host_FTDI_Serial_Monitor
• https://reprap.org/forum/read.php?1,236755
• https://github.com/AlphaLima/ESP32-Serial-Bridge
• http://www.circuitsathome.com

Source:

• https://github.com/tobozo/ESP32-3DPrinter-Bridge