LoRa Mobile Messenger Project

This week has been productive! We started and finished this project. and it came out great!

If you have never heard of Meshtastic, check out their website at https://meshtastic.org/. It is a off grid mesh networking software/hardware that uses the LoRa low powered radios. They are great for family’s and friends who might live in areas where cell service might not be the greatest.

For this project we are going to need a few things for the client build ( I will be posting a build of a NODE soon, you will need one unless you happen to live in an area with some, OR you live close enough to other clients). Make sure to choose the correct frequency for your location. Here in the US 915mhz is open for anyone to use without any license. There are several devices that you can use ( see the meshtastic website) . The one we will be using is this project is the LillyGo T-Deck with the 915mhz LoRA board. https://www.lilygo.cc/products/t-deck?variant=43087936520373 ( Currently OUT OF STOCK as of 2/20/2024 hopefully they will be in stock soon. )

This unit DOSE NOT have a GPS unit ( Optional) on board, But we will be adding one to our project. The suggested unit is the Ublox NEO-6M or compatible units. We choose to go with this one from amazon and it works great!. https://www.amazon.com/dp/B0B31NRSD2

You will also need some 90degree right angle male header pins. like these https://www.amazon.com/dp/B01461DQ6S/

You will need some wire to connect the GPS unit to the T-Deck. any wire can do but we found these male to male jumpers make the job simple and fast. https://www.amazon.com/dp/B07GD312VG/?th=1

For the External Antenna (Optional but will greatly enhance the range) We went with this kit https://www.amazon.com/dp/B095JTW6XM

The Last thing you will need is a battery for the T-Deck, It has a charging circuit built in so it will charge the battery for you. https://www.amazon.com/dp/B0CG178SHB
The Battery comes with the wrong connector installed. The T-Deck comes with the correct pigtail you need, so you will need to modify the wires ( Caution: Make sure to insulate any bare wires. Preferred method is the solder and heat shrink. )

The T-Deck does not come with a case. But a snap together case was 3d designed by KO4WHD. The case is amazing!! It is easy to 3d Print and snap together. the Battery door does require some M2 screws (or glue) to stay in position. https://www.thingiverse.com/thing:6326198

Putting it together!

First thing we need to do is 3d print the case. I printed mine on an Ender 3 printer. IF you don’t have one KO4WHD sales the cases on his website https://www.ko4whd.us/store/lilygo

Step 2: Solder the header pins on the back of the GPS unit like this pic ( Sorry i didn’t think of getting a picture when i did this)

We are using the accessory plug on the T-Deck on the top right of the back of the T-Deck

Solder the wires to the T-Deck

The Wiring is as follows. ( Reminder the RX and TX are swapped.)

GPS T-DECK

VCC VCC

GND GND

RX TX

TX RX

PPS NOT USED

After soldering the correct connector on the battery is time to put it all together. The GPS antenna fits perfectly on the of the SD card slot with a bit of double sided 3M tape.

The GPS unit will fit upside down inside the back of the case beside the SMA connector ( allowing the LED to shine through the case. ( if u used a light color like i did) ( I missed this picture also, Man i tell ya I’m not a good blogger LOL)

Next is to attach the SMA antenna connector to the case. the star washer goes on the bottom and the lock washer goes on top with the nut.

Next is to attach the battery ( Yes before you Snap everything together because getting to the battery connector is limited) The case has a spot for the speaker i attached it with a bit of super glue.

The Battery Door does need some super glue ( if ur not planning on removing the battery) or some M1.7 or M2 screws. I went with M2 hex head screws.

The last thing to do is Snap the case together! and you will have a fully self contained LoRA enabled Meshtastic messenger! I am also writing code for other projects with the T-Deck besides Meshtastic the t-Deck can be used for tons other projects.