MMDVM Nextion

Nextion Display

Nextion MMDVM startscreen
Nextion startscreen for MMDVMHost

As you can imagine, all titles will be replaced with actual data when connected to a running MMDVMHost (used by pi-star).

What’s Nextion

Nextion is a Human Machine Interface (HMI)solution combining an onboard processor and memory touch display with Nextion Editor software for HMI GUI project development

What’s MMDVM

MMDVM logo

The Multi-Mode Digital Voice Modem is a combined hardware and software development of a modem to handle all amateur digital voice modes.
It now supports D-Star, DMR, System Fusion  (C4FM), P.25 and NXDN.

MMDVMHost is the centeral part of the MMDVM-software.

What’s Pi-Star

Pi-Star is a software image built initially for the Raspberry Pi (produced by the Raspberry Pi Foundation).
The design concept is simple, provide the complex services and configuration for Digial Voice on Amateur radio in a way that makes it easily accessable to anyone just starting out, but make it configurable enough to be interesting for those of us who cant help but tinker.

What' MMDVM Nextion

A combination of all above hardware/software.

  • Connect the Nextion display to your Raspberry Pi or MMDVM modem board
  • Put (upload) a MMDVM-Nextion project (.tft file) to the Nextion display

Uploading a complete Nextion HMI project can be accomplished by either microSD card or over TTL Serial. As there are dozens of manufactures for each of these, it is the user’s domain to know their device installation, configuration and operation.

MMDVM Nextion setup PAØROB
Raspberry Pi + Duplex (Pi-Star) Hotspot and Nextion screen connecet via USB to TTL

MMDVM Nextion HMI project by PAØROB

Below you can download the (ready for display upload) version of my MMDVM Nextion display project.

Nextion DMR screen example
Example of DMR screen

For best results you need to install the NextionDriver on the MMDVMHost machine (mostly a Raspberry Pi with Pi-Star):

Screens and functions

My version of the MMDVM Nextion display contains:

  1. Start screen
    • Hotspot info
    • Button to select interface speed
      • 9600 baud for ON7LDS L3 layout
      • 115200 baud for ON7LDS L3 HS (High Speed) layout
    • Restart button, reboots Raspberry Pi
    • Stop button, halts Rapsberry Pi
  2. D-Star QSO screen
    • including Last Heard
    • Country flag and country name *)
  3. DMR QSO screen
    • Two Time Slots - TS1 and TS2
    • including Last Heard for TS1 and TS1
    • Country flag and contry name on each Time Slot *)
  4. YSF QSO screen
    • Country flag and country name *)
    • including Last Heard
  5. P25 QSO screen
    • Country flag and country name *)
    • including Last Heard
  6. NXDN QSO screen
    • including Last Heard
    • Country flag and country name *)
  7. PACSAG message screen
  8. Mode Screen Tour
    • Tap on right-up corner
  9. Help Screens on
    • Normal Operation and NextionDriver
    • Tour and Navigation
    • Screen Dimming

*) Country flag and country name display developed by Rob - PDØDIB

Mode Tour / Help

 Help button  Tap on the Help button(s) to get some help and to make a tour through the Mode screens.

In Tour/Help mode MMDVMHost no langer send data/info to the Nextion screen.

Help screen

The Left-Up and Richt-Up corner Tap function works similar on all screens.

Returning from Tour mode reactivates the normal information flow from MMDVMHost. 
But ... status which Mode is active is not (re)sent by MMDVMHost. So it may take some time to get the information on the right screen. Or information is (more or less) presented on the wrong Mode screen.

During the Tour and on a Mode scheen, Tap Left-Up corner to Resume normal operation.

How to Resume and get (re)synchronized:

  1. Returning to 'Home' screen and click Left_UP corner.
    Wait until "MMDMV Idle" (under Date Time) is displayed.
    This may take some time (until Mode changes or no Mode is active anymore).
  2. In case information is presented in the 'wrong' fields, an other Mode is active.
    Sometimes it's clear which mode is active (look at the leds of the radio board).
    Go to that Mode display and click Left_Up corner to Resume.
  3. Reboot
Nextion Layout/speed button
High Speed button

Display selection

Select Nextion display and ON7LDS L3 layout
(or ON7LDS L3 HS [High Speed]).
Be sure to select the same layout on the Nextion display.

In Pi-Star go to: 

  • Configuration
Pi-Star Configuration of Nextion display
Pi-Star Configuration of Nextion display


The Nextion part of /etc/MMDVMHost should look like this (as shown in Pi-Star):

In Pi-Star go to: 

  • Configuration
    • Expert
      • MMDVMHost (and scroll to these sections)
Nextion settings (in Pi-Star)


When the NextionDriver is correctly installed, during Raspberry Pi / MMDMVHost start (or reboot) jou should see (for a short moment) a screen like this:

NextionDriver is installed

If the NextionDriver part is missing, check the driver install.

Screen dimming

Screen dimmingOn the start and Help screens there is a slider to dim the backlight. The dim-value is store in the Nextion display and maintained over power-of.

In Pi-Star, leaving RemoveDim to 0 resets dimming on each screen to values specified in Brightness and IdleBrightness.
In this setting (RemoveDim = 0) the dim-slider is of no use.

Set RemoveDim to 1 to let the dimming slider do its work.


For het Nextion display to function correctly you to consider two things:

  1. This project only works on a 3.5inch Enhanced Nextion display !!!
  2. For use of all functions (especially use of the buttons) you need to install the NextionDriver on the (MMDVMHost) Raspberry Pi.
    Here is a description on how to achieve this:

Download section


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