I was wondering if it's possible (or if it would be possible) for Hijack to send a sequence of buttons instead of just a single command when the telephone mute goes on/off. The intended use is to (a) do the normal SaveAux/RestoreSrc thing, but also (b) send a specific IR code through to my user app that will tell it to mute my XM radio receiver. This is necessary because my phone and the XM receiver are both using the aux input, so muting the XM receiver when my phone audio is playing is desirable.

I guess another approach would be polling /proc/empeg_power in my user app to detect the mute status, but if supporting sequences in extmute is an easy tweak, I think it'd be cleaner to get it from IR. Do the button presses sent by the extmute functionality go through IR translate? If so, could I just define a fake button code that gets translated to the sequence I need?

Yes, I believe they do. Untested, but the code seems to use that path for them.


Yup.

OK, I tried testing it out tonight, and as far as I can tell, it is going through the ir_translate. However, I'm seeing an issue where as soon as the extmute is invoked while a user app is running, the app freezes up, as does the entire player, which stops responding to network activity (pings aren't answered, telnetd is frozen, etc.) The only way to rescue it is to pull it out of the sled.

To rule out anything screwy my app is doing, I tried it with empacman, and I got the same result. As soon as extmute is triggered, the screen freezes and the player stops responding to button input. This happens even with a conventional SaveAux/RestoreSrc definition for the extmute settings (i.e. not sending a sequence via the ir_translate path.)

Any idea what might be happening here?

In addition to the aforementioned lockups when extmute is triggered while a user app is in the foreground, I'm now seeing spurious triggering of extmute on/off where it quickly flashes on and then off (telephone icon appears for less than a second.) I'm guessing the voltage coming into the extmute line is temporarily going above/below whatever threshold is defined, even though it's not supposed to.

I know this behavior varies based on config.ini settings in the [sense] section, but I've never seen any reference to the exact voltage levels. I have mine setup to trigger extmute on 12v, but the actual voltage seems to be closer to 11v, and the specs for the device say "Actually, the 12V B Status output voltage will drop to about 9V at the max. current of 100 mA."

At the times I'm seeing these intermittent flashes of extmute on/off, the extmute line is supposed to be at 0v, but I guess it's going non-zero. Does anyone know what the exact voltage levels are that trigger on/off actions? And, would these be something that the kernel could have some visibility into or react differently to in some way?