Single Remote

Remote controllers for audio-video equipment have been one of the biggest failures of the industry. The failure comes from the fact they are designed by engineers (and UX is not involved) and in a purely engineering fashion they aim to expose every piece of (often not used or even not understood) functionality. On top of that, to do some very basic tasks, like playing a video, you need to operate two or three remotes - one for the display, one for the audio equipment and one of the video source device.

It has been like that forever and even the introduction of the bi-directional digital AV interconnection standard (HDMI) has not solved this problem. HDMI has a great but little known feature called CEC, which is designed to solve the multiple remotes issue. And as I wrote before, it is little known and even less used / implemented. Even Apple, a company which is proud of its user experience - first designs, failed to recognize CEC until generation 4 of their Apple TV product (4 is the one with the AppStore).

Luckily, with the arrival of Apple TV 4, the CEC protocol is very well implemented on Apple's side. It automatically discovers other connected HDMI CEC devices, including audio systems (to allow controlling volume with the Apple TV remote) and displays (to turn them on or off and switch to a proper input when playing content).

There is some challenge though, if a device like Apple TV is used with older video / audio subsystems, which do not support CEC. And there are plenty like that. Unfortunately, there is no universal way of upgrading non-CEC equipment to understand CEC - you need to hack. Inspired by the excellent work by Thomas Sowell, I set off to upgrade my AV setup. I tried variety of CEC approaches in the past and Thomas'es is the simplest you can imagine requiring an ATTINY microcontroller and almost no external components.

My setup is an (old) Panasonic PT-AE2000 projector and an (even older) Bose Lifestyle audio system (none understanding the CEC protocol). For the Bose I have applied a dirty hack to emulate the Bose remote key presses for volume up/down and power/standby control. For the Panasonic projector I only needed on/standby, which can be done via the projector's serial port, so I made a simple device which interprets CEC commands and converts them to RS-232, which the projector understands.

Now, I wanted a HDMI switch, to enable multiple inputs. The projector has 3 HDMI ports, but that would require running three cables across the room and the ceiling. A switch, especially one with an audio extraction capability (to feed the Bose unit with analog audio) is a nice solution, allowing in my case up to 4 HDMI sources. It looked simple until I realized HDMI switches do not implement CEC. After trying several units I found one claiming CEC support and mentioning Apple TV as the use case.

It turned out the CEC "support" has been a mere wired connection of Pin 13 (the CEC pin) from Input-1 to Output-1 on the switch. That would still serve my use case (passing CEC from the Apple TV to the projector), but while Apple TV had no issue controlling the projector over CEC, it ended up with a blank screen after the switch was inserted in the signal path. I contacted the vendor who explained "CEC of course works, you just need to power up the projector BEFORE powering up Apple TV". That of course invalidated the whole idea of CEC, as it is the Apple TV that must be powered first to send CEC power on sequence to the projector. The vendor declined acknowledging this was a problem (and therefore I do NOT recommend that product), while I found a (very) dirty workaround - you need to manually (using a pushbutton on the HDMI switch) cycle through the inputs and the image reappears. CEC hacking to the rescue - I programmed yet another ATTINY microcontroller to do the pushbutton presses automatically if it detects the "one touch play" message sent by the Apple TV.

As you see, a long story involving multiple hacks to solve the world-old problem of having multiple remotes. I can now, just using the Apple TV remote, press a button and play a video, and be able to control volume, and the whole thing shuts down when the show ends.

I'm not sure what to  think about it in the end. It is just simple and obvious, I would say the most basic functional requirement. All protocols to do that exist. Yet it requires soldering and programming skills and three microcontrollers to patch the functional gaps in products. Clearly a failure, from the industry perspective.