r/meshtastic

I’ve been working on a project for the last little while that I figured this group might appreciate.

I picked up an old Motorola T900 two-way pager with the goal of completely replacing the original electronics, but keeping the original case, QWERTY keyboard and Lcd. I had one in 2000 and loved it.

The biggest hurdle was figuring out the original Motorola hardware. There’s basically no useful documentation out there for the display, so I ended up reverse engineering both the keyboard and LCD myself. After a lot of probing and experimenting, I now have both working with a modern microcontroller.

Right now the prototype is running on a Heltec V4 with an ESP32-S3, so the hardware is already there for Meshtastic, Wi-Fi and Bluetooth.

The obvious next step is Meshtastic.

I’m working on a prototype interface now that keeps the general feel of the original T900, but the idea is to take it quite a bit further than just making it a Meshtastic terminal.

A few things I’m playing with:

- Meshtastic messaging using the original keyboard and Lcd (Sending messages just fine so far)

- Bluetooth connection to an Android phone for receiving and replying to SMS through your normal phone number

- Wi-Fi messaging between devices through a separate pager-style messaging service

- Wi-Fi/Bluetooth configuration and updates

- Classic little 90s/early-2000s games like Snake

- A Tamagotchi-style virtual pet app, because it seems like exactly the kind of ridiculous thing that belongs on one of these

- Original EL backlighting

- Vibration and old-school pager/phone alert tones

- Rechargeable lithium battery instead of the original AA setup

Basically I want it to still feel like a T900, just with everything you’d want one to do in 2026.

I’m also thinking about building a simple pager-style messaging service where each unit has its own pager ID/number, with direct messages, channels, pages/acknowledgements, etc. It could use Wi-Fi when available and Meshtastic/LoRa when it isn’t.

The prototype is still very much a work in progress, but getting the original screen and keyboard under my control was the part I wasn’t sure would even be possible. That’s working now.

If there’s enough interest, my eventual goal would be to design a drop-in replacement PCB shaped specifically for the T900. Ideally you’d take a donor T900 apart, remove the original Motorola electronics, install the new board and reuse the original screen, keyboard, case and conductive connectors without having to hack everything together like my prototype.

I’m curious how much interest there would actually be in something like that. Would you guys want a T900 conversion board/kit if I get this to the point where it’s reliable?

I’ll post more as I make progress. The photos are from the current prototype/software work, so definitely not a finished product yet.

Really excited to finally get this fully built.

This is a CicadaTAK MANET. It's a Raspberry Pi-based HaLow device with 2.4GHz and either Mesh LoRa protocol. It integrates with ATAK, though the base iOS/Android app is killer on its own. You connect your phone to it via its 2.4GHz AP, and if you add the third antenna (middle, here) you can use 2.4GHz for super close, high-data. HaLow handles the mid-ranges and Meshtastic handles the long range. Heltec V3 or V4 integrated inside. It uses OpenWrt, Morse Micro, and Batman-adv. Green TPU seals, printed top/sled/spine and bottom caps, and an aluminum body, all purchasable if you don't have a printer.

The app gives access to the public Meshtastic channel too, as well as a private team-comms channel; alongside that, all the stuff you'd expect with ATAK:
- a live map with your squads's nodes and pathing
- push to talk
- photos
- if one node gets Ethernet or an internet uplink, every other node does too
- the mesh auto-negotiates which protocol provides the strongest meshing (2.4GHz, HaLow, LoRa)

Other cool things:
- you can onboard standalone Meshtastic devices, keep their names (though it overwrites the default chat channels), and give them access to the IOS/Android CicadaTAK app to use chat and mapping, without having the full MANET build
- M12 Ethernet, dual-USB-C bulkheads
- 10,000mAh battery
- you can print any combination of top caps to fit any array of antennas and ports (BNC, SMA, etc)
- you can download map tiles while uplinked for offline usage

Loving it so far. The guy dev'ing them (cicadaxbuilds) on Instagram is super responsive since his build guides aren't out yet. Only quirk thus far is that the internal Heltec device doesn't like to be used by the Meshtastic app, only the CicadaTAK app, as it's powered and plugged into the Raspberry Pi.

CicadaTAK.com

Very excited to be able to contribute and GROW THE MESH!

I'll be tinkering with these on the weekend, any advice or ideas are more than welcome!

Thanks for inspiring!

ps: I live close to Barcelona, hope to see the fellow nodes around!

I found a 7 foot tall 915 MHz colinear vertical probably 5 to 8 dbi gain in my 30 year old antenna graveyard. Plus masts and roof tripod. I've been holding off money in case I still couldn't reach anyone but I found I already have an antenna that's about as good as it gets. This is an example of what getting old and losing your memory is like but sometimes it creates a nice surprise. I'll clean it up and test it.