As we know each Nextion Display has its own unique Serial Number.
It is written on the box, the sticker at the back of the screen and it’s stored somewhere in the memory of the screen as well.
Is there any command or simple way to read only this specific bit of information so it could be displayed on the screen?
The only place where the SN is displayed is when you connect the screen to the computer and start debugging on it.
I wonder if someone figured it out
There is nothing to figure out. It’s officially documented on the Nextion website for the upload protocol v1.1.
You’ll have to send a specific string over UART (from PC or MCU) and you get a string back from the display, containing among others the display format and the serial#.
connect command used as part of the upload protocol will send you back the SN and some other helpful info. Details here: https://nextion.tech/2017/12/08/nextion-hmi-upload-protocol-v1-1/
I’m aware of “connect” command and that its giving me the SN in the output. But that requires a USB to TTL adapter. My question was, if there’s a command that can be executed on a standalone Nextion display and show serial number on the screen. I searched through the Nextion Instruction Set but can’t find anything that could help me.
So “connect” with a USB to TTL adapter is the only option
Yes, the external option is the only one, the Nextion interpreter has no public access to this data. An USB-TTL Adapter is one option, integrating that “sysinfo” request into the firmware of your connected MCU is another.