Comms issues with grblHAL on Teensy 4.1 when trying to poll from ESP32

[SimpleSophon]

Hi,

I am trying to add wifi connectivity with a ESP32-WROVER-E for my Teensy 4.1. I compiled the code and loaded it to the Teensy. When it comes up I do get the normal response from "$$" and "$I" so I believe that it is functional. I have tried with both serial and SPI between the devices and I never get a response from Grbl. I did verify that the devices work together by just running a simple 2 way test of communications with serial and SPI and no problem there. I realize that no one can say much without me providing my code, but is there anything inherently problematic with this? Is there anything that has to be done to Grbl to allow it to respond to requests over serial or SPI? I have also tried this with a ESP32-S3 and an Arduino Nano ESP32, same result. I understand that an ESP32 is a common way to add wireless connectivity to a Teensy so I feel like I can't be the first one to have this issue and want to verify that this is possible and that I am not a giant dummy.

[terjeio]

Wireless options are available via Bluetooth (virtual serial), and ESP-AT (telnet). Both uses UART comms. Some drivers supports Ethernet via SPI but not wireless. Are you using MPG mode or a custom plugin to interface with the ESP32?

[terjeio]

The wireless I’m adding is for WiFi so I can get updates on the process of a job.

So you want to replicate the output the sender gets to the ESP32? No input? Then enable MPG mode 2.

[SimpleSophon]

If I wanted to send and receive between the ESP32 and the teensy, what would I use?

[terjeio]

Depends on how you want to use it:

• Only connect via the ESP32 UART then select (Virtual) UART in the Web Builder (or comment out this line).
• Switch to the ESP32 UART when a client connect to the ESP32 - then something like the ESP-AT or HC-05 plugins. ESP-AT is by switching on connect detected in software, HC-05 by detecting a pin change. You will have to write your own plugin if ESP-AT cannot be used.
• Switch to the ESP32 UART via a control character (0x8B) or just listening on real-time reports then MPG mode.

"ESP UART" is the wired connection between the ESP32 UART and the Teensy UART.

[SimpleSophon]

Thank you very much, I will try that.

[SimpleSophon]

@terjeio that did fix my issue, I am very thankful for your patience, I now see that there is a comment in my_machine.h that specifically says to comment out or set to 0 to use UART communication for "define USB_SERIAL_CDC".