Re: [opendiag] Help me please !!!!!!!!!!! ISO9141 and KWP2000 !!!!!!!

Hi

i believe you realise the ISO-UART fonction with software
first be sure ( disable the interrupts of pic while transmitting the ISO char or init pattern ) . stay in 10300 to 10500 baud ( 1%)
trig on 50% of incoming ISO signal and use a timer to measure the baudrate.
sometimes ECU runs at lower baudrate than 10400 ) you have 96 uS of time tosample it. If you use C for PICs you can have problem while sampling the input ( delayed )
perhaps collect first the signal in Ram and work out after ;o)

B/R
Bülent
  

----- Original Message -----
From: nakapuff2001
To: opendiag@yahoogroups.com
Sent: Monday, January 12, 2004 2:04 PM
Subject: [opendiag] Help me please !!!!!!!!!!! ISO9141 and KWP2000 !!!!!!!

Hi everyone !

I made an interface which is 'hardware correct'. I made also a small
software for PIC16F876 which can communicate with a PC at 9600Bds and
which is able to deal with ISO and KWP2000 at 10400Bds.

Ok, I've got a serious problem ! The vehicules I have (A year 2000
Peugeot 206 diesel and a Year 2000 Subaru GT turbo)
I guess that the peugeot was KWP and the subaru was ISO9141.
Anyway, I tried to generate the Slow Init Sequence and then the fast
init sequence....

But poor I am !!! I 've got no response from the vehicule, either the
206 or the subaru...

So I verify the signals at the K and L lines and I have exactly what
is described in the ISO normalizations...

For the Slow INIT, I have : 0X33 (LSB first) à 5Bds, then I 'm
waiting for the 0x55 for baudrate detecting (10400Bds it should be !)
and for the KW1 and KW2, then I send the invert of KW2, and the ECU
should answer 0xCC....
But the only thing I have on the line is the generating of my 0x33 at
5Bauds and nothing during the next 300ms.... So my program goes out
and tell me no response.... There is no response from the vehicule...

For the Fast Init, I'm doing this :Wait 300ms at the high state, then
generate low level for 25ms then high level for 25ms then I send 0xC1
0x33 0xF1 0x81 0x66 and I'm waiting for a reply... But nothing
happen..... :(((

I send the same things on K and L line synchronously... perhaps it's
this ?

I use the K line, the L line, the signal Ground and the positive
supply voltage on the obd plug... Is this correct... I guess yes !!

I'm desesperate, because my signals are perfect... 25ms+-1µs... The
10400Bauds is exactly generated.... I don't understand....

If someone is able to help me or to tell me what's wrong ??!! What
can I do better than perfect signals ???????????????!!!!

I see everyone working on it without difficulties, humm I miss
something but what and where ??!

Thank you in advance !

Bye

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Received on Mon Jan 12 05:22:47 2004