Hijack v299 and dimmer inconsistency problems

After upgrading to hijack v271 to v299 I started to have problems with the dimmer function. At 100% sometimes the dimmer appears to be at about 90%. When I go to adjust the dimmer it appears to already be at 100% but if I rotate one click beyond that it will go to what looks like 100%, one more click the same direction and it will go back to what looks like 90% again, all while still displaying 100% on the indicator. Going the other direction there seems to be similar inconsistencies at other levels. Sometimes the display will be unreadable by only 80%. When in normal operation, the dimmer doesn’t seem to work properly in conjunction with the “lights on” input either. If put it in my car and boot up sometimes it will start at a level lower than 100% and if I turn my lights on it will become even darker, then if I turn the lights off the display might return to a “real” 100% level sometimes, sometimes not. There have even been times when the display will become brighter when I turn the lights on. The unit was working better but not perfectly on v271 and v291 exhibits the same sort of behavior.

Got the same thing. Was wondering whether I should report it first, or try the default 2.0b13 kernel, or dive into the source and figure out how the display is dimmed, so I ended up doing none of the above

In any case, when the player powers up it is often quite dim, flipping the dimmer settings down to 90 and back up to 100 'cures' it, and sometimes simply toggling the headlights fixes it.

Try removing Hijack. If that doesnt work, see this thread:
http://empeg.comms.net/php/showflat.php?Cat=&Board=empeg_general&Number=68872

It is unlikely that your dimmer problems are related to the hijack software. Please see this faq entry about the dimmer.

Note that the flicker problem described there is most prevalent when the player is physically cold.

I think people are misleading you here in telling you it's the dimmer fix... I had the exact same problem on my player. - it went back to cambridge and said it was the dimmer problem, and claimed it was fixed... As soon as I got back, there it was again. I bet there are lines of lighter and darker parts of the display when it's having issues?

Anyways, to fix it, try reflashing a whole rio image... That fixed it for me, at least.

Matthew

I had noticed something while browsing through the hijack diffs.

In empeg_display sendcontrol, the kernel makes sure that at least 1/10th of a second has elapsed before setting a control line from high to low. The comment that goes along with this is something like "make sure that the PIC is listening". However, it never adds this delay when going the other way around. So I'm assuming that it is possible that the display PIC never sees the line transition when dealing with back-to-back commands.

So I've added the same delay for the low->high transitions, built the kernel and reflashed my player. On my first test it seemed to work, but repeating the test showed that in some cases it was still getting confused. Now it gets the dimmer setting wrong about every 4 times I switch my headlights on/off instead of almost reliably every time. It also seemed like knob turns were detected more reliably, sometimes turning the knob in one direction would actually be registered as if it was turned in the other direction.

In any case, I also included a one-liner that should fix the source switching bug when returning to a userland application, and put the image and patch up for download at the bottom of the gpsapp page.

Perhaps others can test to see whether my observations are completely subjective, or whether I'm on the right track here.

You talk about "rotating one click", which suggests to me that you're using the knob. There are known problems using the knob to adjust the dimmer, as they are controlled by the same PIC. If the problem goes away when you use the remote control, this is what you're seeing.