I wanted to make my zigbee router as small as possible. This is the result. I use this router to extend my zigbee network powered by zigbee2mqtt running as an addon on home assistant.
So most possible this is a thing a very short amount of people will need/use.
Things you need:
You can follow this youtube video to flash your router (not from me)
Also this tutorial will help:
1) desolder the pins from your zigbee router (to make it as flat as possible). Keep in mind that you will have to solder wires to you module if you want to reflash it in future.
2) desolder der pins from your c2102.
3) glue the c2102 at the back of the router. It's important to line it up as I did to fit the case. Maybe its better to print the case before to use it as a template while gluing it.
4) connect the 3.3V pins and the GND pins of the two modules. Use a flat insulated wire. Don't short something out!
5) Take the printed parts, put in your device.
IMPORTANT case_p1.stl: rotate 60° y-axis, use brim and support IMPORTANT
case_p2.stl: rotate 180° y-axis, no brim, no support
Buy ready2use stick:
If you are interested in buying one of those or a cc2531 with an antenna mod, than have a look here: http://zigbee2mqtt.discourse.group/t/ad-buy-ready2use-zigbee2mqtt-stick-flashed-antenna-mod-and-printed-case/22