Dear Olivier I’ve seen yesterday your product demo on the Home Assistant event, and I found there’s a gap on the market you could fill in.
There’s the very common use case, which people usually face later:
- when you buy a TV, and you want to hook a pair of good speakers to it, you suddenly realize it only has a digital TOSLINK audio output.
- the TV remote volume control doesn’t act on the digital output so you can’t control volume of the speakers
- you want Home Assustant TTS announcements on the same speakers
- you may want another auxiliary audio source like an FM receiver or something
- a good quality pair of speakers has balanced XLR or TRS input connections
Currently there’s no such product on the market that could solve this issue for the people but with an ESP32 and with some additional compoments this could be done very easily by you and your team, and not too expensive either.
Look at the diagram I’ve made below:
- The ESP32 (could be running ESPHome) would be in charge of receiving network streams and forward them to an I2S stereo DAC. It could also command the peripherals:
- Use a GPIO IN/OUT pair for an infrared receiver and transmitter, to catch the TV remote signals (ESPHome supports decoding them, so you can adjust volumes with TV’s remote). The transmitter could be used to send codes to “relay” translated codes some commands to other devices around (set top box, for example).
- Via I2C it could command some simple analog volume controllers, to help with external soruces gain equalization (for example SPDIF and analog sources levels should be aligned, also “master” output level).
- A last pair of GPIOs could be used to command an analog sources switcher (simple binary control).
- Output should be splitted and offer connectivity with SPDIF/TOSLINK, analog RCA stereo and 3.5 jack headphone, and of course balanced XLR or TRS jacks.
Software-wise you could rely on ESPHome, there the 80% of the work is done now, just need to add some support for volume controllers and the source switcher, which compared to the rest of the work shouldn’t be too difficult.
What do you think?