forum.pistar.uk

Greetings,

Some time back, I had a working Nextion screen, using the excellent layout by Mitch, EA7KDO. It worked fine. And fast.
I am not entirely sure what I did next, but it would not communicate with the Pi3b any more.

I found the answer in that I needed to write a very simple hmi file to have a first line of "bauds=9600"

This I then compiled, and fed into the screen, after which it worked. But slowly, as it has continued to this day. I had loaded the high speed driver, but to no avail. Today, I had a (very rare, Hi) bright idea:

Using the on-screen button (in the "flash" page of the screen), I set it to 115,600 baud, and of course, it stopped working. Using my web browser, I accessed the Pistar, and changed the driver to the high speed one. (ON7LDS L3 HS).

It did NOT work. But when I placed the screen USB plug into a different USB port, it worked fine. I had been plugged into the top USB port next to the network port. Now, I am plugged into the top USB port furthest from the network port.

My guess is that when I did a screen update directly from the computer and the Nextion software, I inadvertently plugged into a different USB socket. Which could indicate that different screen drivers may use different USB ports. Maybe someone could shed some light on this?

So, if someone else has had similar grief, the above may help...

73 de Stan, G4EGH

What model R-Pi?

Pre-Model 4, the Ethernet jack is managed by the same chip that manages the USB-2 ports. Model 4B have a distinct Ethernet chip, and also have a pair of USB-3 ports (as I recall, these are the blue USB ports).

Another thing, using a different port may have triggered a new "device" detection and assigned it a different path and found the other driver. The old port may have had a path/driver pair that were out-of-date -- but were remembered by the OS so removing and inserting the device attached to the pre-learned path/driver set.

A Pi 3b+

That is a good theory regards the pairing of the path/driver.

You are right re the Pi4 regards the USB3 ports, although I guess since there are still four ports to choose from, it could happen again. I will have to try it with a pi Zero 2. Should be fast enough, but only one (micro) usb port.

73 de Stan, G4EGH