[mythtv-users] LIRC not detecting certain keypresses with MCE remotes (modifiers?) - evdev timings SOLVED

[Tim Draper]

---- On Thu, 23 Jul 2015 20:23:58 +0100 Tim Draper  wrote ---- 
>evdev IR commands are working now, using both 'MCE Keyboard' and 'MCE SE' devices in myharmony for the mythtv activity. The first giving me full keyboard options, the latter SE device allowing me ALT+# use.
>
>evdev worked pretty much out of the box and uses both the event4 and event5 streams as previously mentioned, depending on exactly which command the remote is sending - the 'MCE Keyboard' device will be detected in event4, others in event5.
>
>I've opted to configure as much as possible on the myharmony side so future mythtv installs will be as painless as possible.

I figured I'd just update this thread incase i dont get around to creating/updating the mythtv wiki pages with this info.

reading though http://lists.x.org/archives/xorg-devel/2011-May/022109.html shows that evdev has an emulated KEYUP event for IR signals. since this is emulated, it waits for a pre-defined delay of no input (250ms by default) before sending the KEYUP event. It seems that either the Logitech Harmony 650 or NUC hardware is not quite perfect timing so when buttons are held down for a certain time, randomly, things get confused where mythtv acts like the button is still held down even though ir-keytables shows no input from the remote.

The solution is mentioned in that archive thread, increase the Delay and Period values to more IR-friendly settings. For my NUC with 2 events for the IR receiver, I adjusted as follows. they are just the first values I'm testing, but so far it's made a noticeable improvement in key reliability. The first lines with 250/33, 500/125 are the kernel default values on mythbuntu14.04. Second line is obviously what i've changed them to:
$ sudo ir-keytable -d /dev/input/event4 -D 500 -P 200
Repeat delay = 250 ms, repeat period = 33 ms
Changed Repeat delay to 500 ms and repeat period to 200 ms

$ sudo ir-keytable -d /dev/input/event3 -D 500 -P 200
Repeat delay = 500 ms, repeat period = 125 ms
Changed Repeat delay to 500 ms and repeat period to 200 ms

hopefully that helps someone out - it's just taken me many hours to find this info and also how to actually define new values.