Odp: Serial data hardware solution

[Marek Skrzypiec]

Hi Ross
There are many solutions for doing  that interface , but there is only one
question :
What do you require  the amplitude on diagnostic connector - 5 V(TTL) or 12V
?
If 5V - link together Rx and TX - but it isn't the good solution , because
when you send something , automatically  you receive your message which you
send .Yuo can solve a difficulty by adding transitor (working as KEY ) and
pull up resistor to RX .The TRANSISTOR BASE is controlled by microcontroller
.
if 12V - there is only one difference : contverter TTL<->12V . to convert
TTL-> 12V use CD 40109, to convert 12V->TTL CD4050 and the rest is as above
.
Marek

-----WiadomoϾ oryginalna-----
Od: Ross Myers <ponty at axis.jeack.com.au>
Do: GM ECM List <gmecm at efi332.eng.ohio-state.edu>
Data: 29 paŸdziernika 1999 09:44
Temat: Serial data hardware solution


>Hi all,
>
>On all the Microcontrollers  I've seen the UART has separate Tx/Rx pins,
how
>can this be interfaced to the GM bi-directional data without the use of the
>Delco 64606 I.C.
>I'm hoping there is a 'simple' solution.
>
>Thanks
>
>Ross Myers
>
>