About DB9 Female connecte to HCS12

Started by cwl_hf121 July 24, 2011
Hello,This is my first time to do one carte based on Hcs12 using SCI
module. I have one RS232 cable M/F, one DB9 Female connecte to HCS12.But
I'm not sur which one of connection is right in the picture.
Picture
Thanks for all your help.


If you want it to be a DCE device (which I guess you do since it is a female
connector) then pin 2 should be TX (out from controller) and pin 3 should be RX
(in to controller). This way you can connect it with a straight cable (or no
cable at all) to a PC, which is a DTE device that has RX (in to PC) on pin 2
and TX (out from PC) on pin 3.

/Ruben

> Hello,This is my first time to do one carte based on Hcs12 using SCI
> module. I have one RS232 cable M/F, one DB9 Female connecte to HCS12.But
> I'm not sur which one of connection is right in the picture.
> Picture
> Thanks for all your help.
>
>
>
STOP!

You cannot hook your DB9 directly to the processor pins. RS232 usually uses +12/-12V signals. Your processor is 3V or 5V. Connecting it directly to RS232 will destroy the processor.

You need something called an RS232 transceiver chip like the Maxim MAX232.

Look at an example of how to use the MAX232 chip here:

http://www.coolcircuit.com/circuit/rs232_driver/

Andrei
On 2011-July-24, at 9:05 AM, cwl_hf121 wrote:

> Hello,This is my first time to do one carte based on Hcs12 using SCI
> module. I have one RS232 cable M/F, one DB9 Female connecte to HCS12.But
> I'm not sur which one of connection is right in the picture.
> Picture
> Thanks for all your help.
>
>



hello,
Thanks very much, I have done the test, it works.

--- In 6..., "Ruben Jsson" wrote:
>
> If you want it to be a DCE device (which I guess you do since it is a female
> connector) then pin 2 should be TX (out from controller) and pin 3 should be RX
> (in to controller). This way you can connect it with a straight cable (or no
> cable at all) to a PC, which is a DTE device that has RX (in to PC) on pin 2
> and TX (out from PC) on pin 3.
>
> /Ruben
>
> > Hello,This is my first time to do one carte based on Hcs12 using SCI
> > module. I have one RS232 cable M/F, one DB9 Female connecte to HCS12.But
> > I'm not sur which one of connection is right in the picture.
> > Picture
> > Thanks for all your help.
> >
> >
> >
> >
> >
> >
> >
> >
> >
Hello,
In fact, chips12 is a hybride module who is integreted with one transceiver chip.
Thank you all the same.

--- In 6..., Andrei Chichak wrote:
>
> STOP!
>
> You cannot hook your DB9 directly to the processor pins. RS232 usually uses +12/-12V signals. Your processor is 3V or 5V. Connecting it directly to RS232 will destroy the processor.
>
> You need something called an RS232 transceiver chip like the Maxim MAX232.
>
> Look at an example of how to use the MAX232 chip here:
>
> http://www.coolcircuit.com/circuit/rs232_driver/
>
> Andrei
> On 2011-July-24, at 9:05 AM, cwl_hf121 wrote:
>
> > Hello,This is my first time to do one carte based on Hcs12 using SCI
> > module. I have one RS232 cable M/F, one DB9 Female connecte to HCS12.But
> > I'm not sur which one of connection is right in the picture.
> > Picture
> > Thanks for all your help.
> >
> >
> >
> >
>
>