a few weeks ago i took the whole system out (except left the monitor and keyboard mounted), and began slowly troubleshooting all my intermittent issues by adding only a single cable and or accessory at a time and then using the thing in each configuration for several days to make sure where the problems really were. here's what i found out:
- my longer cable for my CarTFT.com display would work with power, vga, video, but the usb touch panel portion would randomly stop working and show up as an unkown device in device manager (win7). whenever i removed this longer cable and put in the shorter cable that came with the display, everything was fine. i verified this several times. i thought i had a bad cable, or it was just too long to work due to noise or voltage drop. turns out that the longer cable was not meant to work with my 5-wire touch version of the screen, only with the 4-wire versions - doh!
- whenever i had the touch-screen and the receiver for the wireless keyboard plugged into the same hub, the mouse action from either would work super slow and somewhat erratically. i finally realized that the carnetix hub is actually 2 individuals hubs electronically (as per device manager), and as long as i plug the touchscreen into one of those (say ports 1 or 2) and the RF mini keyboard into a different one (ports 3 or 4) then the mouse and touch action both work just fine. i read recently about usb 1 and 2 and "multiple transaction translators" in hubs -that probably has something to do with the issue.
- the biggest issue, the car power adapter i had gotten for the laptop from ebay. apparently it was "browning out" when the jeep wasn't running, even though i had 12.74 volts. i just happened to notice that the power light on it was pulsing when the jeep wasn't running sometimes. the laptop had it's own battery power, so it wasn't really affected, but since the adapter was powering the dock, which had all the usb breakout on it, the browning out was randomly resetting all the usb devices. this is the second time a cheap power supply has kicked my a$$ with electronics projects lately - resolution: only buy quality power supplies from now on!
for a couple weeks i had everything sitting just in the back seat with just the shorter CarTFT breakout cable and wired up using a new iGo power adapter that worked fine with the jeep off. with this setup, everything began to stabilize! i was able to then isolate only 2 remaining issues. 1) the iGo doesn't survive engine cranking, so i ordered a carnetix power supply. 2) i went back to the globalsat gps now that other issues are fixed, but it will loose it's 3d fix once in a while. this happens in plain view of the sky and the fix establishes again within a couple minutes at most. it's only happened twice, and on longer trips, so not sure what the resolution to this issue is.
so i'm eagerly awaiting the carnetix supply and i'll test for a while with it before i try to mount everything out of site again.
Attachment 66355
