Meshtastic Heltec T096 – Best Solar Build
I’ve recently gotten back into Meshtastic and built a couple of solar nodes. For my second node I used the Heltec T096 Mesh Node.
In my opinion this is the EASIEST solar node build that is out there. There is no shortage of solar node projects out there on the interwebs. Most of them are based around the Harbor Breeze solar lights ($9.98).
My key considerations for choosing the Heltec T096 is simple. The board includes a Battery Management System (BMS) and the only hookups are to the battery and to the solar panel. In the Heltec T096 packaging there are 2 power cables with the correct sized JST connectors for the board. Solder one across the battery terminals and solder the other to the solar panel. That’s it.
Here is what Heltec says about their BMS – “Integrated lithium battery management system (charge/discharge management, overcharge protection, battery power detection, automatic switching between USB and battery power).”
The board also incorporates Bluetooth, LoRa, and GNSS. It is based on the nRF52840 and the SX1262 LoRa transceiver. The GNSS chipset is a Unicore UC6580.
The best part of this board is that the nRF52840 sips power making it perfect for a battery powered installation. The antenna I used is this one.
Setup For Battery Usage
For operating under battery power you shouldn’t use the GNSS (GPS) and probably should turn off Bluetooth. I’m going to leave Bluetooth on for this node because I intend to mount it in a difficult to reach location. If I experience any battery longevity issues then I’ll look at turning it off. I’m also currently using the stock battery that came with the light, a 1500 mAh battery. I have other larger capacity batteries but they are somewhat expensive and I use them in my shortwave radios. If I can make this smaller battery work then that will be great.
Gotcha
When I built this solar node I connected it via Bluetooth to a Mac Mini in my man cave. The Heltec T096 uses a random six digit code for Bluetooth pairing. After I had buttoned it all up I then tried to connect it to my phone. I’ll have to open the case again so I can view the rolling code. Anyway, make sure you don’t make the same mistake as me.
3D Printed Parts
A user by the name of PrintnCrap posted some files on Printables for this project. I printed the Heltec T096 Mount.
The Heltec fits perfectly in the part and you can use double sided tape to secure it to the battery holder. Make sure you bring it down as close to the bottom as possible as you won’t be able to close up the enclosure. In fact in the photo I posted at the beginning of the blog it is installed too high. I didn’t realize it until I tried to button it up. He also has all manner of mounts to 3D print depending on your installation requirements. I used one from another designer.
Finished Product
Currently I have 96 discovered nodes which means it is working pretty good. I kind of live out in the boonies as well. I do need to mount it up high but I want it on the ground for a week or so to continue testing the node. Once confident it is rock solid I will mount it somewhere.
A couple of years ago I set up some Meshtastic nodes and there were no other nodes near me. Suddenly there are 96. That pretty clearly means that this manner of communication is catching on.
Additionally, there are much less expensive devices than the Heltec T096 which can be used in the Harbor Breeze solar light. One such kit is from SeeedStudio ($13.49) and you also need a CN3065 Solar Charging Board and some cables.
NOTE: The cables linked above have the wrong polarity. You can simply pull the red and black connections out of the JST connector and swap the polarity.
For my money the Heltec T096 board is just a much easier and much cleaner installation.