StuartProjects LoRa/SEEED XIAO SAMD21 + FRAM PCB (v2) + 18650 battery holder

The enclosure supports the 020123 (v2) of the SEEED XIAO SAMD21 LoRa + FRAM PCB, as designed by StuartProjects. I have no money interest, but you can buy the PCB here: https://www.tindie.com/products/29426/

The documentation, software etc for that project can be found here: https://github.com/StuartsProjects/Devices/tree/master/Board_for_XIAO_LoRa_V2

and extra info : https://stuartsprojects.github.io/2023/02/17/Improved-Tracker-and-Sensor-Node-for-XIAO-and-LoRa.html

For more general TTN information, please use the Things Network forum. And most importantly, use the learning resources on the TTN pages, as the whole setup/configuration of a TTN application/sensor/device is outside the scope (and support) of this PCB and enclosure design.

Only for very specific hardware/software related information on the PCB/ example software/hardware, see the StuartProjects webpage and GitHub. 

This 3d design supports 3 different 18650 battery holders, so it should be compatible with most of the single 18650 holders one can have laying around:

• Full size PinThroughHole
• Full size SMD
• slimline pre-wired

The open-back SMD 18650 holder is not supported because it has no mounting hole(s), its only mechanical connections to the outside world are the to-be SMD soldered tabs.

The PCB itself has no mounting holes, as the original design idea seemed to be to use as little space as possible and potentially hang it under a weather balloon. 

So, to still have a proper fixture, I made the PCB rather hard friction fit longitudinal and designed 2 side wedges to lock up the PCB further. One can use a dab of superglue to ensure the wedges stay in place. If it's too hard to get the PCB in place, a whiff with a file can be enough to make it fit.  

The mounting of the battery holder and the lid happens with self-tapping M2x5 screws.

The lid has 4 corners with easily cut-away, designed-in supports and a 0.2 mm sacrificial layer covering the 4 mounting holes, for ease of printing. With a sharp object you can punch through and clean up with a sharp knife or just use a screw through it.

The USB port is covered using a plug which stays in place with friction fit.

The case has 2 ‘ears’, they can be used to screw it onto something or hang it somewhere. If not needed, they can be cut away.

Make sure you wire-up, program and test everything before mounting, it makes life easier.

Printing can be done with any material. For outdoor -sun exposed- use, I recommend ASA.

Non-direct sun exposed or inside use: can be ABS or PLA, depending on temperatures. When using with temperature sensors inside, preferably printed in white, as that will absorb the least heat and will distort the readings the least.

Reprogramming using the USB is always possible, but at least make sure you don't have to take it out any more for simple hardware adjustments. 

As there are endless ways of connecting/setting up, I can't give too much advice on how to do things. I only made a -minimal- case to allow mounting it in a slightly more professional way.

I'll be using it with Dupont connectors on the 3.3V, GND, SPI, I2C and RX/TX lines, so I can plug in what I want on top without soldering. A dab of hot glue or foam on the lid will ensure the sensor module says well-connected with the MCU/Lora module.

Of course, I'm always open for suggestions/corrections/improvements on the 3d design.

Feel free to remix or use this idea in any way, shape or form in your own designs.