UART on esp32

[joergBeigang]

I am trying to stream gcode via uart on a esp32. So far I couldn't convince grblhal to listen to what I'm sending.
I was building with #define MPG_ENABLE 2
What I read so far is, when sending x8B it should switch modes and report it in the status report (tried sending it via uart as well as websocket).
For some reason it doesn't report anything like that. And did I get this right that in case it's working it should listen to TX2D and RX2D (on the esp32 this would be pin 17 and 16)?
Is this feature supported on the esp32? It's building without any complains ...
Or is there something I don't see yet?
Thanks
Joerg

[terjeio]

It is supported but not for all boards. Which did you compile for?

[joergBeigang]

A mks tinybee

[terjeio]

Ok, it is pin 16 and 17 and it is working when I just retested. I connected to the MPG port with PuTTY (Win10) and sent the 0x8B character by using the numeric keypad (in NumLock mode). Pressing and holding the <Alt> key while typing 1 3 9 and then release the <Alt> key will send the 0x8B character and toggle MPG mode.

Are you sending the 0x8B character code or do you send it as a string (all four characters)?

[joergBeigang]

Really appreciate that you took the time to look into it!
I actually tried to send it from both ends, with the sender software via websocket (was quicker to put 0x8B on a button than to figure how to send hex via minicom) and via uart:
In the sender I'm pretty certain that it's working, cause all other hex commands are (snipped: data = bytes.fromhex(hex_data.replace("\n", ""))

via uart on the jog wheel side it looked like this:
uint8_t byteToSend = 0x8B;
GRBL_SERIAL.write(byteToSend);

Maybe I messed up with compiling the firmware. I only set this: #define MPG_ENABLE 2 but keypad and macros I kept off.
Tomorrow I'll pull the latest data (my local version is a little older) and compile it again.
Thanks!

[terjeio]

Be aware that the 0x8B character has to be sent from the MPG, not the sender. And do not send line termination characters (CR and/or LF) along with it.

[joergBeigang]

That's good to know. I did program the jog wheel so send 0x8B every 10 seconds to see if anything is happening . It's gonna work at some point. Thx

[joergBeigang]

Got it working. In the end it was my own inability to code.
I was a bit surprised that once it's in MGP mode the communication to the sender is totally cut off, not even receiving anymore.
Now I'll think about it, if I use it or better do some kind of "man in the middle approach" that would give me a bit more control on what is sent to what device.
Again, thanks a lot for your support!

[terjeio]

I was a bit surprised that once it's in MGP mode the communication to the sender is totally cut off,

It is not, it will receive status reports but nothing else. For that the MPG has to request the status reports while it is in control or you have to enable auto reporting by setting $481 > 0. IMO it is best to request the status reports.

[joergBeigang]

$481 is brilliant, very clean solution.
Just one more question: is it supposed to report via uart in both modes? Right now I'm not receiving anything.

[terjeio]

Not sure what you mean by "both modes".
Anyway, status reports are output to both the main sender and the MPG regardless of the mode or which client requests them.
Output of any other data is only to the client requesting it.

BTW I am testing with a ESP32 dev board running the Tinybee firmware - if you do not get any output to the MPG then the pin map or wiring is incorrect?

[joergBeigang]

Was my esp32 dev board. Tried with an pico w and it's working. Strange thing.