forum.pistar.uk

I am using Nextion displays in combination with 3 of my my hotspots (DVMega with RaspberryPi model 2 and 3).
I have 2 x 3.5 inch and 1 x 3.2 inch enhanced models with the model 8 Globe screen images from Rob PD0DIB (without the ON7LDS drivers which I do not need).
It works fine in the modes DMR and D-Star, but is causes audio drops (every 4 to 5 seconds) in the transmitting stream in C4FM mode (no problems during reception).
This is what I have tried, all without succes:
1. I have changed the configuration between connection via USB (using a TTL-USB adapter) and the GPIO port of the RPI -> no change
2. I have interchanged the screens (3.5 inch and 3.2 inch) -> no change
3. I have interchanged the different Raspberries and DVMega's (also using the DVMega- Bluestack with the USB connection)-> no change
4. I have added ferrite cores to the wiring between the Raspberry and the Nextion screen -> no change
I wonder how I can resolve this problem.
Any thoughts??

73's, Tom
PA2TSL

At first, thanks for your response.
I have tried both of your suggestions, but it does not help:

I have set the MMDVM display type to 'None' in the configuration (so everything is still connected).
The Nextion display returns to the 'static' standby display as a result.
At the same moment the dashboard is present on one of my PC's.
The result is that the problem is GONE! No interrupts any more!
It can be reproduced very consistently in this way.

So the Nextion screen should be active in order to get the problem back.
I have also submitted this issue in the Facebook Pi-Star Support Group, so I hope to get some more tips.

Anyway, thanks for your input!

73's, Tom
PA2TSL

I am still struggling with this 'audio-drop' problem that I have submitted in this forum about a year ago.
The Pi-Star version has been updated / upgraded to 4.1.2 (dashboard version 20200528) in the mean time, and I did not notice any improvement.
In addition I have connected a second 5 V power supply to the Nextion display separately to be sure that the Raspberry Pi /DVMega has sufficient power from it's own power supply, not affected by the display. The only connection is the data in- and output between the Nextion display (via the USB-serial adapter) and the Raspberry USB port.
This action also did not fix the problem.
I did not use the Pi-Star dashboard, so this could not affect the operation as well.
So still no solution, and the problem has been reproduced by another ham using the same configuration, so I am not unique with this...
This problem does not happen in DMR and D-Star mode, so I will not use the screen in C4FM mode to avoid the audio drops/hick-ups..
Of course, I am very interested in a solution, and I hope that anyone can help me with a solution.

I have set it to 9600 Bd (ON7LDS L3) and I have changed it to 115200 Bd (ON7LDS L3 HS). The problem exists in both cases....
Btw, I do not use the ON7LDS Nextion driver which you can add to Pi-Star, so I have limited functionality (for me that's ok).