Serin & serout

Archiver

Hi All,

I wrote a C program to send commands to the stampII.
The stamp should then respond to the commands. For
example C program sends "*SN\r\n" the stamp should
reply with "SN=12345".

Ok now the problem is that the stamp seems te echo
back the command before the reply. It first sends
"*SN\n" and then "SN12345". (I just want the
"SN12345")

I am using pin 16 for both serin and serout. Why
does this happen? Will it always happen?
How can I prevent this.

=============================================
Code:

---

Serial Data "SN12345",0
Start Var Byte

---

Init :
SerIn 16,16468,[noparse][[/noparse]Str Serstr\10\cr]
if SerStr(0) <> "*" Then INIT
Gosub Choice
Return

Choice :
If SerStr (1) = "S" Then ShowSerial
If Serstr (1) = "V" Then ShowVersion

Return


Both ShowSerial and ShowVersion just routines that
sends a string out with Serout.

But before the program can get to choice the "*S\r\n"
is echoed back.

Thanks for You Help
Danie






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Archiver

I think the problem is not in the code but in the connections. It sounds like
you have the data in and data out lines from your PC both going to the stamp's
I/O 16. If so, your PC is probably talking to itself. Test this theory by
removing power to the stamp. I bet you get the same "echo" behavior. My
suggestion on a fix is to use any of the I/O pins 0-15 as the input (with an
in-line limiting resistor as recommended in the manual). Then use 16 as your
output, as it comes closer to the 232 levels. Good luck.

Clark Hughes

didv wrote:
>
> Hi All,
>
> I wrote a C program to send commands to the stampII.
> The stamp should then respond to the commands. For
> example C program sends "*SN\r\n" the stamp should
> reply with "SN=12345".
>
> Ok now the problem is that the stamp seems te echo
> back the command before the reply. It first sends
> "*SN\n" and then "SN12345". (I just want the
> "SN12345")
>
> I am using pin 16 for both serin and serout. Why
> does this happen? Will it always happen?
> How can I prevent this.
>
> =============================================
> Code:
>

---

> Serial Data "SN12345",0
> Start Var Byte
>

---

> Init :
> SerIn 16,16468,[noparse][[/noparse]Str Serstr\10\cr]
> if SerStr(0) <> "*" Then INIT
> Gosub Choice
> Return
>
> Choice :
> If SerStr (1) = "S" Then ShowSerial
> If Serstr (1) = "V" Then ShowVersion
>
> Return
>
> Both ShowSerial and ShowVersion just routines that
> sends a string out with Serout.
>
> But before the program can get to choice the "*S\r\n"
> is echoed back.
>
> Thanks for You Help
> Danie