Newbie Question...

All things relating to the Nextion Screen(s)
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ae4ja
Posts: 5
Joined: Sat Oct 02, 2021 12:20 am

Newbie Question...

Post by ae4ja »

OK, new to all of this, here's the setup:

Raspberry Pi 3B
Generic Chineesium MMDVM_HS_HAT_DUPLEX modem board from eBay
C4LABS case
Nextion NX3224K024 Display

I've had the Pi for years, never did more than run different versions of Raspbian on it and fool around. Recently purchased two ICOM ID-31A HT's at the Shelby Hamfest (MONSTER deal, paid $100 for the pair!) only to find out that there's a total lack of D-Star infrastructure in the area. I initially purchased a couple of simplex hotspots from a different eBay vendor (a whole different fiasco) then purchased the Duplex board. I slapped it on the
Pi 3B and installed Pi-Star. Off to the races! The learning curve was a bit steep at first but now I've got a basic handle on things. I've made several contacts via D-Star and YSF so the modem is happy. A few days pass, and my case and screen show up. Now comes the hair-pulling... The display powers up fine, but all I can get out of it is the "demo" stuff. I've read enough posts here and other places to sink a battleship, all to no avail. Yes, I've got the right modem selected in Pi-Star, I even tried selecting a few wrong ones just to see what happened. I've tried all of the display combinations in Pi-Star several times over, still no dice. I've wiped and reinstalled Pi-Star half a dozen times to make sure none of my futzing around corrupted anything. I even tried switching the TX and RX lines between the modem and display since I got conflicting information as to whether or not to cross them. (I'm old enough to remember needing crossover ethernet cables in some situations and built a bunch of them in the day.) At this point I can't say if the modem, display, or software is to blame. It just may be the loose nut behind the keyboard, I'm man enough to admit that too. I don't have another MMDVM board or display to swap out to eliminate or blame either of those.

I've been a professional auto and light truck mechanic for over thirty years, and I'm pretty good at diagnosing and repairing electronic systems, but a lack of diagnostic equipment and spare parts has me stumped. I have no way of testing for data transfer between the Pi, the modem, and the display. I've got a feeling that's where my issue is, either the data isn't getting thru, or some part of the system isn't doing what it should with that data once it gets there.

Anybody got a suggestion, before I pull out what hair I have left?
KE7FNS
Pi-Star Team
Posts: 2147
Joined: Wed Apr 17, 2019 11:11 pm

Re: Newbie Question...

Post by KE7FNS »

ae4ja wrote: Sun Oct 03, 2021 12:10 pm The display powers up fine, but all I can get out of it is the "demo" stuff.
Well, welcome.

You've mentioned that the screen only shows the demo stuff, so that leads me to think that you have never installed a compatible .hmi/.tft on it for it to work with MMDVMHost.

I suggest:
https://github.com/PD0DIB/Nextion_HAM-r ... w%20Series

Another thing is how you are connecting the Nextion, by USB/TTL adapter or by the modem. Each one requires the default baudrate to be a specific speed.

The first part of this documentation should explain all of the things needed to get a Nextion working properly. (Just stop when you get to install the Nextion Driver unless you want the extra Nextion Driver fields)
viewtopic.php?f=20&t=3397


I've written up some more documentation explaining things further, hopefully they will set you in the correct direction.

viewtopic.php?f=20&t=3447
viewtopic.php?f=20&t=2196
viewtopic.php?f=20&t=3799
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
ae4ja
Posts: 5
Joined: Sat Oct 02, 2021 12:20 am

Re: Newbie Question...

Post by ae4ja »

I'm connecting it thru the SDL/SCA header on the modem board. This sure has turned out to be way more involved than the seller of the screen and case implied was involved. You'd think they'd provide more instructions than "solder in the wires and plug it in..."

I'll read up on what you posted this evening after work and maybe I can make some progress, everything I've read about drivers and such said the drivers and such were for upgrading the drivers once you had a working screen but I can't even get to that point yet. I guess I need the book "Nextion Screens for Dummies"... =)
KE7FNS
Pi-Star Team
Posts: 2147
Joined: Wed Apr 17, 2019 11:11 pm

Re: Newbie Question...

Post by KE7FNS »

ae4ja wrote: Mon Oct 04, 2021 10:53 am I'm connecting it thru the SDL/SCA header on the modem board.
SDL and SCA are i2c. Nextions are standard RS232 serial. There should be a 4 pin port on the modem board labeled NXT. Make sure the configuration is set to "modem" and the default speed of the Nextion is set to 9600 baud.

It will work then. (when you also upload a MMDVM compatible .tft to the Nextion)
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
ae4ja
Posts: 5
Joined: Sat Oct 02, 2021 12:20 am

Re: Newbie Question...

Post by ae4ja »

I hadn't had any coffee when I posted my last, and had the picture upside down. It's hooked to the header with the gnd, txd, rxd, and 5v+ labels, which is the serial header IIRC. Sorry about that. So looks like I need to do the other stuff, but I should have the right connections to the board at least. This may take several days for me to work thru everything as I'm swamped at work and will be pretty much brain-fried by the time I get home each evening.
ae4ja
Posts: 5
Joined: Sat Oct 02, 2021 12:20 am

Re: Newbie Question...

Post by ae4ja »

OK, I downloaded the NX3224K024_Model 10-2.4inch_DPLX_Enhanced_v1.05 file and installed the Nextion editor. I can't for the life of me find where to change the baud rate. If I had known I was diving into the deep end here I would have gotten the one with the small OLED screen that comes installed. I set one of those up for a buddy on Sat. and it went easy peasy. =(
KE7FNS
Pi-Star Team
Posts: 2147
Joined: Wed Apr 17, 2019 11:11 pm

Re: Newbie Question...

Post by KE7FNS »

ae4ja wrote: Mon Oct 04, 2021 11:54 pm It's hooked to the header with the gnd, txd, rxd, and 5v+ labels, which is the serial header IIRC.
Yeah, make sure TX on the header goes to RX on the Nextion and vice versa.

Also another common mistake for that configuration is people mistakenly put "/dev/modem" instead of just "modem". Also don't select "/dev/ttyAMA0" as that is the main serial port that is already in use by the RPi and modem.
ae4ja wrote: Mon Oct 04, 2021 11:54 pm This may take several days for me to work thru everything as I'm swamped at work and will be pretty much brain-fried by the time I get home each evening.
No problem, the forum is always here.
ae4ja wrote: Tue Oct 05, 2021 12:32 am OK, I downloaded the NX3224K024_Model 10-2.4inch_DPLX_Enhanced_v1.05 file and installed the Nextion editor. I can't for the life of me find where to change the baud rate. If I had known I was diving into the deep end here I would have gotten the one with the small OLED screen that comes installed. I set one of those up for a buddy on Sat. and it went easy peasy. =(
You can change the baudrate manually using a USB/TTL adapter and the Nextion Editor.

A long time ago I created a file that someone could load externally that would allow you to select the baudrate but I'm not sure if you have the same model.

Try download/file.php?id=395

If that doesn't work I'll have to make another one. Is yours basic, enhanced or intelligent?

Download the file to a FAT32 formated SD card, extract the .tft to it. Then with the power off on the Nextion, insert the SD card, and power on the Nextion. It should come up with a white screen. If the model matches it will begin writing. Then power the nextion off, remove the SD card and power it back on again and then you should be able to select the 9600 baud box. Then power it off and load whatever screen you downloaded.
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
ae4ja
Posts: 5
Joined: Sat Oct 02, 2021 12:20 am

Re: Newbie Question...

Post by ae4ja »

Success!!!

Finally figured out where to stick the "bauds=9600" command into the Nextion editor, exported it as a .tft file onto my SD card, stuck it in the slot on the screen, and we were off to the races. I still need to put the better Nextion driver in yet, but I'm making progress. :D
KE7FNS
Pi-Star Team
Posts: 2147
Joined: Wed Apr 17, 2019 11:11 pm

Re: Newbie Question...

Post by KE7FNS »

ae4ja wrote: Tue Oct 05, 2021 1:53 am Success!!!
Congrats. :D
ae4ja wrote: Tue Oct 05, 2021 1:53 am Finally figured out where to stick the "bauds=9600" command into the Nextion editor.
I'm not sure if you manually ran the command once or if you stuck the command into the PD0DIB files you mentioned earlier.

If you did the latter, you really don't need to have that "bauds=9600" remaining in the .hmi/.tft. Running the command once wrote to the memory on the Nextion so it should always power on at 9600 from now on.

I would remove it just in case you ever try to use a USB/TTL adapter as you will probably forget you added that command and you'll never figure out why it isn't working (cause in the future if you manually run the command and then as soon as the script runs during initialization it resets back to 9600 without you realizing it), and anyone helping you isn't going to realize you added that command to the file.
If someones previous actions are any indication of their future actions, then I predict the deletion and removal of access will happen at any moment. 7-11-2020.

"07/13/20 This Website Has Been Taken Down" ... again :lol: and again
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