forum.pistar.uk

How are you powering you Nextion 3.5 screen on a Raspberry Pi3+ with a MMDVM board over the GPIO pins? Using the MMDVM board to power it up? or other ways?

There are two ways I know of to connect a Nextion display:

• Via a USB to TTL UART CH340G Serial Converter, plugged into the RPI's USB.
• By connecting to the Serial through-holes on the radio/modem board.

In both cases, the connection should provide the power you need, with the exception that some people have experienced that they don't get enough power when using the Serial connection (I've personally had no problem with 3.5" displays using the Serial connection). In that case, you can solder the power and ground wires from the Nextion to the 4 (5V) and 6 (GND) GPIO pins on the RPi.

As an alternative to soldering, I've hacked the Pimoroni FanSHIM to provide power by snipping off the arms that hold the fan as well as the wires that connect to that fan, and then using the FanSHIM as to connect to whatever needs power. You can see more about this in my hotspots article by looking at the note "Using the Pimoroni Fan SHIM as just a shim" in the cooling fan section (https://amateurradionotes.com/hotspots.htm#coolingfan).