I am sure I followed all steps exactly to get hooked up to the modem pins on the Zumspot. However, results were the same The Nextion starts on the MMDVM screen during initialization and connection and then goes to a NextionDriver starting screen where it waits until I apply changes on the MMDVMHost config section. The Zumspot works we know because it was fine on the RPi 4. Plus it is fully functional after apply changes. I even tried a brand new Nextion screen as I mention below. So unless there is something wrong with my Pi Zero I am lost. I have detailed my work below.
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Etcher install Pi-Star_RPi_V3.4.17_20-Jan-2019
Booted and logged into pi-star setup
Restored Archive holding only my basic configuration options and wifi info
Changed remote password
Changed Nextion port in MMDVMHost Config to Modem and left ON7LDS L3
Shut down Zumspot
Restarted Zumspot and double checked settings
Installed NextionDriver from Putty using Installation Program and only
git clone https://github.com/on7lds/NextionDriverInstaller.git
This resulted in NextionDriver being installed with port of “modem”
Opened pi-star interface on my laptop and checked that Nextion Port in MMDVMHost config was now /dev/ttyNextionDriver which it was.
Opened Expert and checked MMDVMHost Page. In Transparent Data ‘Enable=1’ had been set and ‘SendFrameType=1’ had been added to the page.
TFT Serial section port was ‘modem’. Changed it to /dev/ttyNextionDriver
In Nextion section port was /dev/ttyNextionDriver
In NextionDriver section port was ‘modem’.
Rebooted and Nextion screen went to NextionDriver started screen after wifi connection was established.
Apply Changes had to be used from the MMDVMHost configuration section to proceed. Zumspot hotspot is functional and two way contact between DMR parrot is fine. NextionDriver controlled buttons such as reboot and shut down work correctly. This is the same result as when I was using the USB/TTL adapter from the Pi Zero USB port.
Changed TFT Serial section port back to ‘modem’. No change in action.
Nextion connected to directly to Zumspot modem pins. A brand new connection cable was used.
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Etcher install Pi-Star_RPi_V4.1.0-RC2_08-Jul-2019
Manually loaded all configuration information. No previous configuration archive was used.
All else as above with same results. Everything stops at NextionDriver starting screen after connection is established. Apply Changes has to be run from the MMDVMHost Config section. (Really about anywhere as long as changes are applied.)
In final desperation, I pulled out a brand new basic 3.5 Nextion screen being saved for another project and flashed it with the Model 8-3.5inch_GLOBE-SIMPLEX_v1.2 by PD0DIB. Same result. Loads MMDVM screen during initialization and connection and then goes to NextionDriver starting screen where it patiently waits for me to apply changes.
As I reported in an earlier post V4.1.0 RC2 is far slower to initialize, connect or respond to changes than V3.1.17 on my Pi Zero. Additionally, the CPU temp is about 5 degrees Celsius higher.