Serial Port problem transmitting a Decimal 43 character.

[pdablue]

Hi,

I have encountered a problem when trying to transmit the Decimal
character 43 across a serial port connection.

I have written the following two programs:

ASCII128.sbp

This program should transmit a specific ASCII character (0-127),
one time, each time a button is pressed.

BINARY256.sbp

This program should transmit a specific BINARY character (0-255),
one time, each time a button is pressed.

I encounter a problem when I try to transmit a Decimal character 43.

I want to be able to press the Decimal character 43 key one time and
transmit the character one time across a serial port connection. Instead,
I have to press the button 4 times before the program will transmit
anything. When the program does transmit, it transmits 4 characters
at a time.

This process repeats over and over again when I try to transmit a
Decimal character 43.

I have tried the following serial DLLs and I get the same results
no matter which serial DLL that I use.

SerialDevice.dll
Serial2.dll
SerialEx.dll

I am using Net Compact Framework version 2.0 on the PDA device.

The PDA that I am using is an HP IPAQ H2210.

Has anyone else encountered a problem when trying to transmit a
Decimal 43 character across a serial port connection from the PDA
to an external serial port device?

Here is the basic4ppc source code for the two programs that I
have written.

Below are the installation files for the PDA device:

The zipped up (.CAB) installation file for the ASCII 128 program is:

asc128.zip

The zipped up (.CAB) installation file for the BINARY 256 program is:

bin256.zip

[pdablue]

Hi,

I found out what was going on with Decimal character 43 which is the
+ sign.

Issuing three +++ sign characters puts my BlueSMiRF Bluetooth module
into command mode.

So, the Decimal character 43 is being transmitted properly by the
Basic4ppc program.

[Zenerdiode]

A lot of modems reserve this character sequence as the 'Escape Sequence' and you may place the remote modem in its command mode. Ironically, you may send a stream of characters including the +++, but the escape sequence (for the Hayes Command Set) is invoked if you have a pause of at least one second, the '+++' then another pause for one second. That's probably why your device is waiting for more + characters.

Send "Test +++ this message" in one go any you'll see it transmits through OK.

[agraham]

Originally Posted by Zenerdiode

the Hayes Command Set

Ahh! That takes me back to when a 300 baud Hayes modem was a thing of envy!

[pdablue]

Hi,

I recompiled the ASCII128 and BINARY256 programs to run on
640 x 480 PDAs in QVGA mode.

Here are the zipped up (.CAB) installation files for each of the
Basic4ppc programs:

asc128qvga.zip
bin256qvga.zip