Hello all,
I built a Meshtastic node with the Heltec Vision Master E290 and added a buzzer, vibrator and power switch. The biggest thing is to add the mosfet to turn on and off the GPS with 3 clicks of the user button.
Everything is working with Meshtastic 2.5.7. The case is the biggest issue, to fit all these things in and a large battery, you need to expand the back cover or add a bulge. More on that soon.
Th epower switch is a simple 2 position slider that you connect inline with the positive side of the Lipo 3.7v battery. A better way would be to add a smart circuit that can charge the batter even when the device is switched off. I will cover this in another post, it can be used on almost all the Arduino / Meshtastic devices and replaces on board charging that can be flakey.
Similar to this diagram you get the point on where to add the button. Using a simple solar / usbc charge controller and relocating the charging usb port you could replace and move the charge port somewhere else. Draw back is USB serial will still need to be done with the onboard USB connection. In this diagram I am only sending power to the charge board.
Option C – Future Pogo Pin charging
This has a Lipo battery charger built-in, similar to below. There is a connector for the power button, Li 3.7v Battery, and the mini JST connector to the Heltec Board. I am testing this prototype and will get a case printed up with the pogo pins integrated soon. Pogo pin charging does not replace the need for USB-C to program the device. It just supplies power to the board to charge and run the device and keeps the power switch from being soldered to the battery, sorry my OCD does not like soldering to the battery.
Here is one I did for a cheap yellow display. Little more advanced. You could use a solar charger that allows for USB-C power, Solar Power, simultaneously charging the battery, and keeping the device powered off. Ultimately that is why I created this design is to be able to power the charger without the Arduino being powered up saving power when your in the field.
