The proliferation of DIY 3D printers has been helped in large measure by the awesome open-source RepRap project. A major part of this project is the RAMPS board – a single control board / shield to which all of the other parts of the printer can be easily hooked up. A USB connection to a computer is the usual link of choice, unless the RAMPS board has the SD-Card option to allow the 3D printer to operate untethered. [Chetan Patil] from CreatorBot built a breakout board to help attach either the ESP8266 WiFi or the HC-05 Bluetooth module to the Aux-1 header on the RAMPS board. This lets him stream G-code to the printer and allow remote control and monitoring.
While the cheap ESP8266 modules are the current flavor of the season with Hackers, getting them to work can be quite a hair tearing exercise. So [Chetan] did some hacking to figure out the tool chain for developing on the ESP module and found that LUA API from NodeMcu would be a good start. The breakout board is nothing more than a few headers for the ESP8266, the HC-05 and the Aux-1 connections, with a few resistors, a switch to set boot loader mode and a 3.3V regulator. If you’re new to the ESP8266, use this quick, handy, guide by [Peter Jennings] to get started with the NodeMCU and Lualoader. [Chetan]’s code for flashing on the ESP8266, along with the Eagle board design files are available via his Github repo. Just flash the code to the ESP8266 and you’re ready to go.
One gotcha to be aware of is to plug in the ESP module after the printer has booted up. Otherwise the initial communication from the ESP module causes the printer to lock up. We are sure this is something that can be taken care of with an improved breakout board design. Maybe use a digital signal from the Arduino Mega on the RAMPS board to keep the ESP module disabled for a while during start up, perhaps? The video after the break gives a short overview of the hack.