Trying to get serial port working for communication with alarm system

I’ve migrated from Windows OH2 to RPi4 OH3, and the serial port interaction is a little different than I’m used to. On Windows, I simply had this line in an items file:
String NX8V2_Panel “Security System” (Security) {serial=“COM4”}

Does anyone know how I can tell what serial port I’m connected to on RPi? My ZWave device is connected to /dev/ttyACM0. I have a rule already that triggers on “Item NX8V2_Panel received update”, which reads the buffer via NX8V2_Panel.status, and sends commands via NX8V2_Panel.sendCommend, so the one item takes care of all the 2-way communication with the alarm panel.

Do I need to be concerned with the config menu? i.e.:
(all RPi) Disable serial console to give room for HATs
(RPi3/4) move Bluetooth to mini UART


I got a little further. I figured out that /dev/ttyUSB0 is the port in question. I can use the “screen /dev/ttyUSB0” command in Linux to get feedback from the alarm panel, so I know that part is working. Yet, in OH3, the serial port buffer doesn’t seem to be getting any data back. My items file now reads:

String NX8V2_Panel “Security System” (Security) {serial="/dev/ttyUSB0@9600"}

Is there some configuration I need to make in OH3 to get it to communicate over this serial connection? This worked in OH2 on Windows, sigh…


Your item definition is refering to the OH 1.x serial binding which is no longer supported in OH 3.x.

There is an OH 3 version of the serial binding so you will need to read the documentation and update your config for the new binding.

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Well, that’ll do it! Nice catch. Thanks.