|Release Date:||August 2018|
|Materials Used:||film faced plywood|
|Tools Used:||Raspberry Pi|
Since existing bluetooth speakers do not provide enough power, Martin decided to build custom speakers for usage on the camping ground of different festivals.
The system is based on a regular Rasbian Lite installation, which gets adjusted by the installation script in the following way:
- Installation and configuration of mopidy and useful extensions
- Installation and configuration of bt_speaker
From an electronics perspective, the system uses a Raspberry Pi in combination with a X400 HAT. It gets powered by a couple of lead batteries.
The wiring is as follows: GPIO 22 & GND are connected to the shutdown button. GPIO 14 & GND are connected to the status LED.
The case is built with film faced plywood:
Check possibility to use a ESP32
On the last Festival, I was mainly using the bluetooth functionality. Playback using Mopidy as well as the Wifi Hotspot was not really used. For bluetooth playback, a ESP32 should be enough. This should lower the needed power significantly.
Shutdown board in case of power losses
Since the system is powered by batteries, there is a possibility of sudden power outages due to a lack of remaining battery power. Therefore, there should be a circuit which either switches from one battery to another and then possibly sends a shutdown signal to the system.
Note: This is only needed for Raspberry Pi based systems.
So far the system is based on Visaton PX-10 speakers. Since they don't provide Thiele/Small parameters, I didn´t calculate the needed box volume and just made a 12 liter box for each speaker, which is most likely way too much.
The next version should use different speakers where the ideal box volume is known.
Make a workshop out of it
Once the new design is complete and tested, there could be a seminar in which we teach others to build their own bluetooth speaker.