One can easily buy USB Bluetooth dongles which claim 60m or even 100m of range. But after only 2m and one thin drywall they loose connectivity all of a sudden. That needs to be rectified! Weapon of choice is a propper antenna and a custom stand.
Disclaimer: The new antenna will increase the EIRP. That’s the point of getting a more useable range. If you rebuild this project, make sure that you don’t violate local regulations, especially in regards of maximum allowable RF radiation. Also, don’t break your USB ports. 😉
- 1x bt-antenna-top1.stl (transpatent blue material)
- 1x bt-antenna-top2.stl (transpatent blue material)
- 1x bt-antenna-bot.stl (TPU)
- 1x Slide switch SS12D00G3 (8x4mm)
- 1x 2.4 GHz antenna with pigtail and u.fl connector
- 1x USB bluetooth module
- 1x USB cable
- 1x 5x5mm (neodymium) magnet
Files and more detailed instructions are available at: https://www.thingiverse.com/thing:4626654
The most critical part is connecting the new rod antenna to the module. My BT module uses a combined microstrip & coplanar waveguide approach to connect the chipset to the printed antenna. With the standard material sizes it just so happens that this geometry matches the geometry of an u.fl connector perfectly, resulting in minimal reflections. I cut the trace to the antenna with a scalpel and peeled of the printed antenna. After scraping the solder resist of, the u.fl connector can be soldered on.
The bottom part is printed in TPU and houses a small 5x5mm magnet in small indentation. That way it has a nice solid grip even on vertical (megnetic) surfaces. The top part uses PETG in transparent blue, so that the blue status LED of the module illuminated the whole top part nicely. I also added a sliding switch in the +5V line so i can enable and disable the module without having to unplug it.
The build was a great sucess, I now have full coverage of my whole appartment from my main PC. Music everywhere! Yay! Makes every chore just so much better. 😀