Incar-Serial

How can I test my incar-serial?
Is the short serial-cable connected to the sled as a crossover?
I was just wondering that my gps works @home using the player's serial and in my car it doesn't.

I think it needs a straight male-male adapter instead of a nullmodem adapter.

So this means the short serial cable of the sled is not a nullmodem (crossover)?
Does the player always output to both serial connections no matter if it is booting 'home-mode' or 'car-mode'?

It is the same device in both cases /dev/ttyS1.

Ok, I did the following:

1. I took the sled out of my car.
2. I connected my computer's serial to the sled's serial using a 1on1 cable. I tried to watch the boot-output using hyperterminal. Nothing happened.
3. Same with a crossover cable.
4. In both cases, the player's LED changed from pulsing to flashing.

I used Hijack to force the player in Car/DC mode.

Warp10, all your questions should be answered by this FAQ entry.

alright i've been gone a while, and i DIDN'T sell my empeg.. so now i have to know..

WHAT GPS is hooking up to the empeg??

I'm afraid not!
I've got the lines

[serial]
car_rate=115200

in my config.ini.
I used Hijack to force the player into car-mode.
I connected the player to the pc using a straight-through serial cable.
I see no output in hyperterminal while booting .

I've connected a "Garmin eTrex venture" to the player's serial port. I wanted to test software discussed in this thread.

Make sure to set your Garmin to NMEA output at 4800 baud (main-menu/setup/interface/nmea in nmea out).
The etrex venture is the same model as I was using when writing it.
I have no car_serial_rate= or notify= options at all, because those are player options and the last thing we want is the player to mess with the serial port.
Did you run hack_init so that the player is started with the -s- flag?
If you use hijack to force the empeg to DC mode you can also connect the gps directly to the serial port on the back of the player.

GPS works if connected to the player's serial, but it doesn't if I connect it to the sled's serial.
What I'm asking was: How can I test the sled's serial?

How can I test the sled's serial?

With a computer and the proper cable, like you said.

Another thing... Some sleds did not have a ground wire on the serial docking connector. Can anyone detail what the work-around was in that situation, so I can add it to the FAQ entry?

That means if I use Hijack to force the player into car mode, AND use the proper cable AND use the sled's serial port AND a normal power supply connected to the 2.1mm plug AND have the car_rate setting THEN I should see the bootup sequence in Hyperterminal like I did with the player's serial port?

Um, Yeah. I think so. Not sure, as my brain stopped functioning earlier today and I don't think it has enough stack space to go that deeply into multiple nested IF statements.

;-(
I don't see the output. Is there a less fault-prone way to test the serial? (Less AND's ;-))

PS: Sometimes the stand-by LED turns from pulsing into flashing while trying to connect with hyperterminal.

You shouldn't need the car_rate setting for the kernel bootup messages. Those as as far as I can see always output at a rate of 115200, but I can check later when I get in my car.

Maybe there's a way to check the serial using a multimeter?
Is it correct that pin 4 has about 14V?

I've found out that if I connect the player's serial to PC Com2 and the sled's serial to PC Com1 and using Hyperterminal to connect to Com1 (the sled), I get output.
I veryfied if the output really comes frome the sled's port by disconnecting the cable. The output stopped at that moment.

I don't understand anything now...

Could very well be the missing ground wire issue, then.

Pin number 5 of the sled port is connected to ground/chassis (Tested using a multimeter) and I hooked up the connector casing to the empeg ground, too.
So which ground could be missing? And, as far as I remember, only some empegs with serial numbers less than a value I don't remember had that problem. But I remember that value was low, at least lower than mine...

Then I've got no idea what's going on, sorry.

Thank you very much, Tony.

What can I do? I need the incar serial for gps testing...

The problem with the flashing LED is not the missing ground problem.

The sled is wired up as half DTE and half DCE:
There are 6 wires on the sled:

TXD on the sled is connected to RXD on the DB9
RXD on the sled is connected to TXD on the DB9

i.e. the sled is wired up as DCE so you can use a straight trhough cable.

BUT

The reset of the connections appear like a DTE
DTR on the DB9 is connected to the amp remote output
CTS on the DB9 is connected to the hedlght sense line
DCD on the DB9 is connected to the mute line.

and theres' ground.

So for some reason the sled port is half and half. If you connect a 9 wire straight through cable to the empeg you will connect your PCs DTR to the empegs DTR (a bad thing) and the empeg will go into this flashing rather than pulsing LED mode.

Don't ask me why they did this. Especially since the sled in the car is more likely to be connected to a device like a GPS/GSM modem which has a DCE connection. The built in connector on the empeg should have been the DCE connection IMO so you could connect with a straight through cable.

The sled issue is fairly easy to correct since you can pop the pins out and swap the TX and RX lines which is what I have done.

INTERESTING!!!!!!

All becomes clear.

I worked around this on my docking station by using only three of the pins (ground, RX and TX). I couldn't get it to work if I used more than those three. Now I know why.

Damn, now I have to rewrite that FAQ entry but I don't know where to begin. I don't have a lot of understanding of what all the pins on a given serial port do.

Anyone want to help?

Thanks alot. I will fix this tomorrow and tell you if it helps.
I love this BBS!

Yeah! It works! Great, thank you very much!
I am just wondering why some users don't have any problems. Are only a few sleds connected "half & half"?

@Tony: Thanx too! Maybe you can get information about the serial port here or here .

I am just wondering why some users don't have any problems.
I guess I was lucky that the sled has a female plug instead of a male. I chained 2 null-modem adapters to be able to plug anything in and that combination probably doesn't pass all nine wires.b

You drained the signal ;-)
That's a possibility, too!

I chained 2 null-modem adapters to be able to plug anything in and that combination probably doesn't pass all nine wires.b

The fact you had to do this does imply the sled is/was wired incorrectly - you should be able to use a straight through cable. Some null modems are 3 wire only which could be the case for one of yours.