Send "Escape" and "Return" keystrokes in RS232

[Badsheep]

Hello,

I'm trying to use the hs.serial module to control a Extron matrix in RS232.
It works quite well : the connection works, and for example if I use :

ConnectionToExtron = hs.serial.newFromPath("/dev/cu.usbserial-BG009E7G")
ConnectionToExtron:baudRate(9600)
ConnectionToExtron:open()

ConnectionToExtron:sendData("1!")
ConnectionToExtron:sendData("2!")

It swiches on the input 1 then 2 as it is supposed to do.

But my problem is that I need to send it commands (for other fonctionnality) that starts with "Escape" and end with "Returns"
I tried that :

ConnectionToExtron:sendData(hs.eventtap.keyStroke({}, "escape"))
ConnectionToExtron:sendData("500VCTR")
ConnectionToExtron:sendData(hs.eventtap.keyStroke({}, "return"))

But it doesn't work, the console gives that error :

2025-03-21 15:27:46: 15:27:46 ERROR: LuaSkin: hs.hotkey callback: /Users/badsheep/.hammerspoon/extron.lua:18: ERROR: incorrect type 'no value' for argument 2 (expected string)
stack traceback:
[C]: in method 'sendData'
/Users/badsheep/.hammerspoon/extron.lua:18: in function 'ZoomMax'
/Users/badsheep/.hammerspoon/extron.lua:28: in function </Users/badsheep/.hammerspoon/extron.lua:27>

Could anybody help ?
Thank you very much !

Badsheep

[Badsheep]

To anyone interested I found the solution :

ConnectionToExtron:sendData("\x1B")
ConnectionToExtron:sendData("500VCTR")
ConnectionToExtron:sendData("\r")