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Nextion Screen no longer working

Posted: Tue Oct 13, 2020 3:26 pm
by M0TJK
I have a K series 3.5" screen, RPi Nano and Simplex MMDVM modem. All was working fine, but no touchscreen. I downloaded the On7LDS/NextionDriverInstaller and the touch screen sort of worked - if you touched it the first time, but the connection to the modem had stopped working; the screen showed "waiting". I am using the correct Nextion/Modem/ON7LDSL3 setting.

I tried the screen attached to another modem (which also has the mini OLED) which I know is working, but the screen still shows "waiting". I tried reloading the .tft file to the screen, but no change. I tried loading a different .tft file to the screen but still the screen shows "waiting".

So, on the face of it, I now have a US screen (and modem).

If the modem is now US that's not so much a problem, but the screen was expensive. Is there any way that I can test or reset the screen to factory please, or is there any way that I can find out why the screen is not working?

Roger

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 6:27 pm
by PA3FAT
Nextion
/dev/ttyNextionDriver
ON7LDS L3

are the settings on my mmdvm hat where the screen is connected to a Nextion header directly on the board.
I have a 'Jumbospot'

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 6:46 pm
by M0TJK
My screen is connected to the 4 pins on the modem and to the Pi by GPIO. The weird thing is that prior to the installation of the (Touch) driver, it was working fine (but with no touch).

Roger

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 7:03 pm
by PA3FAT
then you will need the same settings i have.

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 7:40 pm
by M0TJK
Those were the settings I used for the touch driver, with which I had problems. I just want the screen back to the basic state as it was before I installed the (touch) driver.

Roger

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 8:06 pm
by PA3FAT
why not try to make it work as it should. The default setting is only partially supporting the Nextion screen.

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 8:09 pm
by M0TJK
That can come later. I just want to get the screen back to its basic settings.

Roger

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 8:27 pm
by PA3FAT
all connectors on and to the screen well seated?

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 8:32 pm
by M0TJK
Pins both ends are properly seated. It should be working - but isn't.

Roger

Re: Nextion Screen no longer working

Posted: Tue Oct 13, 2020 8:46 pm
by KE7FNS
M0TJK wrote: Tue Oct 13, 2020 3:26 pm I have a K series 3.5" screen, RPi Nano and Simplex MMDVM modem. All was working fine, but no touchscreen. I downloaded the On7LDS/NextionDriverInstaller and the touch screen sort of worked - if you touched it the first time, but the connection to the modem had stopped working; the screen showed "waiting". I am using the correct Nextion/Modem/ON7LDSL3 setting.

I tried the screen attached to another modem (which also has the mini OLED) which I know is working, but the screen still shows "waiting". I tried reloading the .tft file to the screen, but no change. I tried loading a different .tft file to the screen but still the screen shows "waiting".

So, on the face of it, I now have a US screen (and modem).

If the modem is now US that's not so much a problem, but the screen was expensive. Is there any way that I can test or reset the screen to factory please, or is there any way that I can find out why the screen is not working?

Roger
I don't understand what you mean by "it sort of worked". If the screen responded to a touch input it worked, if it didn't do anything at all then it didn't, there is no "sort of worked". You must understand that when I say "if the screen responded to the touch input", I mean the screen, and not the hotspot. The screen is a stand alone device. There could be a hardware failure or screen calibration issue where your screen is no longer detecting touch inputs, and that would have nothing to do with any hotspot configuration whatsoever.

If I were to guess It sounds to me like your Nextions serial port is not setup to be 9600 baud by default anymore. It probably got set to some other value when you loaded one of those different .hmi/tft's you tried. That seems to be a pretty common issue, in a perfect world the programmer wouldn't of forced such a setting on someone, or at least given them a proper way to choose which one they want. At least if the programmer released their .hmi you can change or adjust this but when they only release a .tft there is nothing you can do.

If you have a device set to one speed of a serial port and connect it to a device that is set at 9600, there will be absolutely no communication between those devices, the serial port speed (baudrate) MUST MATCH.

The easiest way to set the default baudrate would be to find someone that created a screen where you are able to push a button and it sets the default baudrate for the Nextion. Luckly for you I created one a long time ago for another forum user and all I needed to do was reload it in the editor and compile it.

How you use it is load it on to your screen. Then just touch one of the buttons and whatever it says on the lower part of the screen is what it is set to default to whenever power is applied.
NX4832K035_011.zip
(131.43 KiB) Downloaded 50 times
The problem is that if you load a .hmi/tft that sets the default baud rate to something other than 9600 then you are going to be back where you started. You must load a .hmi that you know what it is doing at startup.



You could also have an incorrect setting in your /etc/mmdvmhost file.

For a Nextion connected to the hat the port MUST be set to modem in the [NextionDriver] section.

Code: Select all

[NextionDriver]
Port=modem
That is completely different than the [Nextion] section, it must be set to /dev/ttyNextionDriver for Nextions that have the Nextion driver installed properly.

Code: Select all

[Nextion]
Port=/dev/ttyNextionDriver
1000th post, whoopee. :D