Project:Music Station
| ProjectInfoBox Music Station | |
|---|---|
| |
| Status: | done |
| Release Date: | August 2018 |
| Initiator: | Martin |
| Team: | Martin |
| Materials Used: | film faced plywood |
| Tools Used: | Raspberry Pi |
| Software Used: | Musicbox |
Since existing bluetooth speakers do not provide enough power, Martin decided to build custom speakers for usage on the camping ground of different festivals.
Software
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
Hardware
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:
First draft in SketchUp
First draft in SketchUp
The electronics arrived and had to be tested
Materials for building the box
First part done
The door got attached
Inside of the door
Box built
First test of the assembled box
Added some handles
And finally control buttons
Further Improvements
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.
Different speaker
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.
