[obdgpslogger] ELM327 interface "hanging" with NO DATA condition after a random amount of time (Toyota Corolla)

[Maciej Grela]

2011/9/19 Gary Briggs <chunky at icculus.org>:
> On Mon, Sep 19, 2011 at 12:37:31AM +0200, Maciej Grela wrote:
>> I will disassemble the cable tomorrow but it's from dealextreme so I
>> think it's some kind of clone.
>
> Very likely then, yes.
>
>> Yes, I've seen it happen at least 4 times today. There is no pause,
>> the error messages start immidiately after valid data. Here is an
>> example from one strace'd run:
>>
>> 18:34:54.083039 read(3, "\r>", 4086)    = 2 <0.000039>
>> 18:34:54.083768 write(3, "0111\r", 5)   = 5 <0.000045>
>> 18:34:54.382062 read(3, "NO D", 4095)   = 4 <0.000038>
>> 18:34:54.383060 read(3, "ATA\r", 4091)  = 4 <0.000036>
>> 18:34:54.384060 read(3, "\r>", 4087)    = 2 <0.000037>
>>
>> As you can see there is no pause in data exchange between the PC and ELM.
>
> Looks pretty dodgy to me. That shouldn't really happen in normal usage,
> especially if it's been working up to that point
>
> Could it be as simple as a bad solder joint, or a cable briefly jogging
> loose, something like that?
>

I was thinking about this too but if it were the case the failures
would be more "random" I think, especially as I haven't touched the
cable when the problem happens, I just restarted obdgpslogger. But I
will check the cable just to be sure.

Best regards,
Maciej Grela