Motorized potentiometer for FLOSS remote control

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As part of my Open source audio remote control initiative, I’ve just published Volume-AlpsRK16814MG, an open source hardware design that integrates a high-quality Alps motorized quad potentiometer  with an H bridge. The design lets you control the motor’s direction using two logic-level signals: VOL_UP and VOL_DOWN. The fact that it’s a quad pot means you can use it to control regular stereo volume by ignoring one of the dual gangs or a differential stereo signal.

Here’s the schematic* to give you an idea what it’s doing. Gerbers and PCBs are available at OSH Park.

I’ve also modified the remote control receiver to better support motorized pots. There is now a compile-time option that lets you latch and unlatch the VOL_UP and VOL_DOWN signals rather than produce repeated VOL_UP and VOL_DOWN pulses—which makes control of motorized pots more fluid.

*Subject to change!

Open source audio remote control

audio-remote

I’ve started a FLOSS remote control receiver project for DIY audio preamplifiers. I think it’s just about good enough to make public.

Remote control is one of the more challenging things for an audio DIY person to implement, so I thought having an open source hardware and software platform for doing this would be useful. It uses our good friend Arduino for brains and works with the Philips RC-5 protocol. I like RC-5 because its the closest thing I know of to a universal, well-documented, brand- and model-agnostic protocol.

The IR command decoding is done using Guy Carpenter’s excellent RC5 library. I also considered using Ken Shirriff’s multi-protocol IR library. Ken’s library works with a large number of protocols, but I thought its larger memory footprint might preclude porting this thing to tiny AVRs.

Details on the project are available in my RC5-Preamp GitHub or GitLab repository.