[Android Head-Units] kaween:
Hi there.

If your unit has an external mic connector (may I ask where ? is it "part of your unit as a connector fixed at the rear of your unit, or comes it out as a cable with a 3.5mm female connector" ), normally you shoudl not have to make further modifications inside your unit. There are basically 2 approaches to the external mic issue with the AN21 that I know of :

A) disconnect the internal mic, run a shielded wire from the back of the unit and connect that to the pads of the internal mic.

B) modify the pcb (involves changing 4 smd positions with 0 Ohm connections) and create a specific cable to create the mic break-out. Als in that case, the internal mic has to be sepperated from the internal mic pads to prevent interference and inpendance issues.

Now, here I've got a problem. So far, the AN21's I've personally had in my hands that had an external mic were NOT able give the user the free choice of "either Internal or external mic", as all the ones I've seen so far with external mic connector had a disabled internal mic. There was no switch-mechanism to prevent interference of the two mic's (internal and external) to mutally exclude eachother when you plug an external mic or disconnect it. That's why I ask how your external mic port looks like : if it is an external 3.5 mm female cable, how many wires does it have ?

If your unit has an "internal connector' instead of a cable coming out of the unit, that would mean there's at least one other type of design of AN21 that I'm not aware of, and it will PROBABLY have the "exclude mic conflict" switch a system does need to work correctly.

Just curious, mind you.

As for your problem of "not having sound when connecting the mic that was factory mounted" :

MOST cars with internal mics "from the factory" do not use 2, but 3 wires. The first two are ground and mic output, the third is actually MIC POWER. If your car is like that, "just connecting 2 wires and running them to the unit" will not result in any usable signal, as the MIC itself needs power. How much power that is depends on the Mic electronic design your car brand used. Can't help you there, but a helpful garage owner should be able to get you that info.

As Mike states, incorperating a gyro/magnetic field sensor on the AN21 is well out our reach. Not going to happen.

As for the VGA-cooler, I can tell you from what VGA card it came but it won't do you any good. It was from a Medion-Branded nV7600-passive cooled VGA board : you will not find such a board unless on the scrapyard or in some geeks' cellar (yep, guilty as charged).

That's why I gave you the height specs (13mm) I needed to make the cooling block fit between the ARM and the bottom plate of my unit. I do NOT know if ALL units have the same mechanical specs, so you should check that quoted dimensions yourself on your unit just to be sure. The cooling block must sit tight between the ARM and the bottom plate to work as I intended, but it may NOT be so high that it actually would flex your mcu when you fasten the screws that hold the mcu in place.

[MENTION=6190756]choppyduck[/MENTION] : I'm sorry but I can't help your with that. My cars are all mostly "Canbus-free". :D (read : I own cheap-ass, "what's not there can not break" type of cars with very primitive electronics. Only motor-management runs over Canbus, stuff like A/C and radio are totally independant of it) :)

[MENTION=1915855]KID52[/MENTION] : hello ! Nice to see you pop-up again. It must feel odd to see this thing you started a year ago still being quite active. :)