Has anyone documented any of the the WinCE commands used on the AVIC? I'm interested specifically in how to switch audio sources from a script. From what I have read, I think av.exe can do that given the proper incantation. I want to be able to (for example) watch for an event, like a COM port line changing state, and switch to a different audio source. One example of a use for this would be to detect the signal from an external source (ham radio, CB, scanner, radar detector) and automatically switch to an aux audio input. Putting some sort of visual indication on the screen and sending an audio cue would be nice also, but switching the source would be the win.

Getting an alert signal into the unit looks to be fairly simple; there are FTDI virtual COM port drivers for WinCE on ARM processors, so a common USB to serial converter will probably work. I say "probably" because I haven't tried it yet, but hope to do so in the next few days.

So - what say ye, AVIC software folk?

Short answer: No documentation yet.

Long answer: That's only because no one's had the time to do so. EEGeek's been working with carver on the WINCE.BIN modifying aspect (update the registry and files to add drivers/programs, like the FTDI driver you referenced or the SpecTec 802.11 SD card as an example). See the Wiki. I started working on porting HaRET to our AVICs for the purpose of watching the COM port that controls the uCOM to do the source switching/volume control/etc, but the J-O-B has my undivided attention (well, OK, the large majority of my attention) until the end of April at the earliest. Shouldn't be too difficult, it's a matter of setting up HaRET to observe the memory region the COM port resides in and capturing the writes and reads to the control registers, then executing the command of interest.

OK, fair enough. Next question: Does anyone know, and have a few minutes to tell me, how switching audio sources is done? Is there a (known) command already on the system to do it, as I suspect, or is it done at a lower level by the programs themselves?

OK, fair enough. Next question: Does anyone know, and have a few minutes to tell me, how switching audio sources is done? Is there a (known) command already on the system to do it, as I suspect, or is it done at a lower level by the programs themselves?

Aside from av.exe being the prime suspect where you'd find the use of the API calls, I would investigate the code inside NDeviceLib.DLL, where you'll see such tasty strings as:

NPuComRcvSelectorChangeEvent

NPuComSelectorChg

NPuComRcvSourceEnableEvent

I'm not sure if those are structure names or API functions, but either way I'd say it's worth going at it with WinHex or IdaPro.

I'm more of a hardware guy. I can write my own C code and scripts, and develop products using embedded processors with code I write myself. However, ripping apart code compiled for Windows is a little beyond me at the moment.

I guess I'll have to wait and watch for some of the software pros to do some further digging - or wait until I've got the time to figure out how to reverse engineer the stuff on the AVIC.