serial port headscratching

Hi.

OK, this is a little odd. I want to interface to an external device running at 9600 baud, which I can't change, while in the car. So, I set car_rate to 9600. Simple.

Except that it doesn't work.

After some testing, these are the symptoms:

Normal config.ini, no car rate modifiers, AC power. Serial port runs at 115200, all the serial commands to the player work correctly.

As above, with hijack forcing DC mode. No serial player control commands work, although they are echoed back to the terminal. Ctrl-c drops to a shell which works fine, at 115200. Attempting to connect at 4800, the car default, doesn't work or echo but simply gives garbage.

As above, with car_rate=9600. Same effect, doesn't work at either 4800 or 9600.

Powering the unit from the docking connector without hijack forcing DC mode produces the same result as case 2 and 3 above.

The unit has hijack v320 and Beta13 on it.

Any ideas?

pca

In your test, what kind of terminal emulator are you using? Could the program not be resetting the port speed properly between tests?

I've been using secureCRT, with three different profiles for 4800, 9600, and 115200 baud. It definitely works.

pca

Try it again with notify=0 in config.ini

(weak theory that maybe the port isn't keeping up)

hmm perhaps car rate changes only the serial port on the docking sled and you are connecting to the rear serial port? Another possibility, don't you need to add the "-s" option to the player so it doesn't steal the serial port. Not sure if that's really needed anymore but GPSApp's hacked preinit script did that I believe.

Mmm.. very odd. Same here.

Try a stock kernel.. ?

Doesn't the EXEC_ONCE option now force the player to run in -s mode so input/output is handled correctly?

Ahhh. BINGO, courtesy of Sibera37

Hijack forces -s- to the player when booting on DC power, telling it to not listen to the serial port. This is to help third party apps like GPSapp which want to use the serial for a different purpose.

Mmm... do we need a savearea bit to to toggle this behaviour?

-ml

Try a stock kernel.. ?

Yeah, that crazy Mark guy does all sorts of goofy things to the serial I/O...

Mmm... do we need a savearea bit to to toggle this behaviour?

Is there a reason this can't be a config.ini option (no sense in wasting a savearea bit if we don't have to)?

By the way, if you *do* make this change, I think it should (IMHO) default to the current "trick the player" behavior (makes thirdparty app installation easier).

Well, actually if I do anything I suppose I'll get rid of the "-s-" logic and just have an option to free up (or not free) the serial port internal to Hijack. Then we can have our "notify" data on the road again for things like Emphatic and whatnot..

But that's weeks away at this point.

-ml

Is this why writing SERIAL=xxxx to /proc/empeg_notify doesn't work in the car?

If so, I would greatly appreciate this config.ini switch, because my Palm application inserts songs into the playlist this way, and I would like to be able to use it in the car.

yeah, that would be it!

Two Marks.... both rock climbers... my head is spinning. :P