M5Stack GRBL 13.2 Module serial connection
-
Hi everyone,
I’m trying to communicate with my M5Stack GRBL 13.2 module through serial, but I’m not sure if I’m doing it correctly or if it’s even possible.
I’m currently using a USB to UART TTL adapter connected to my laptop. Here's how I connected it:
- RX of the adapter → TXD2 of the GRBL 13.2
- TX of the adapter → RXD2 of the GRBL 13.2
- GND is also connected between both
I’m not connecting VCC, as the GRBL is powered separately with a 12V adapter.
For now, I'm trying to send G-code commands (like
$X,G1 X10 F100) via a serial terminal (Arduino IDE), but I don’t get any response.My final goal is to connect the GRBL module to a Raspberry Pi 5 and send G-code from it to control stepper motors.
Any advice or a basic working setup would be greatly appreciated!
Thanks in advance.
-
@nathannnn are you sure you can talk to it via uart pins as it looks like they are not connected between mbus and atmega, isn't it I2C path you need to use?
-
@robski The documentation says the GRBL 13.2 module uses I2C, so I originally thought everything had to go through that. However, my main program already communicates over UART, and I’d really prefer not to rewrite everything just to use I2C.
I also tried connecting directly to the ATmega328P pins instead of going through the MBUS, but nothing happened — no response at all.
To troubleshoot, I flashed GRBL v1.1 onto the module, but that seems to have broken everything. It’s no longer responding the way it used to.
Is there any way to make this work over UART reliably, or did flashing v1.1 kill compatibility with the M5Stack ecosystem?
Thx for the answer
-
Just to clarify my motivation:
- I would like to upgrade the Module firmware to GRBL1.1 instead of 0.8
- I would like to communicate with the Module from a raspberry pi via raw serial commands and not the high level I2C Library provided by M5
