A simple analogue attenuator circuit to connect line-level audio to mic-level audio.
The Rode Wireless GO is a nice wireless microphone. We've also been using it, in combination with the audio-level-shifter board to act as a wireless relay for a remote speaker.
Aux out -> audio-level-shifter -> mic input on the Wireless GO transmitter -> Wireless GO receiver -> Aux in on speaker
We've been using this setup to run a second speaker on our group bike rides. The key to getting reliable audio relay across a group of cyclists is to get the radio setup up above everyone's heads. For that we've been repurposing action camera accessories—mostly clamps and selfie sticks. To make it easier to securely mount everything we've designed some 3D-printed sleeves for the Wireless GO with GoPro-compatible fastenings.
- audio-level-shifter/ - Kicad design files for the PCB
- audio-level-shifter-electronics.FCStd - FreeCAD project to wrap the STEP 3D design file generated by Kicad for the electronics
- assembled-audio-level-shifter.FCStd - FreeCAD project (needs v1.0 or later) for the case design
- extras/ - FreeCAD project and output STL file for the Wireless GO sleeve