Bluetooth: Com1 or Com3

Started by lili...@... May 12, 2005
hey, i'm new to this discussion group so we'll see if this works. Here's a question, is there any advantage to using Com3 over Com1 on a BX24? I'm having some troubles using a bluetooth serial adaptor to make my connection to Com 1 wireless and I wonder if Com3 would be less of a problem. I'm sending and recieving info at 19200 baud, no parity, 8 bit, 1 stop bit and it works with a serial cable but not the bluetooth. Anyway, perhaps I'll try dealing with one problem at a time. Thanks

Marcy



> ... having some troubles using a bluetooth serial adaptor to make my
connection to Com1...

Are the Bluetooth modules in cable-replacement mode? Can you connect
the modules successfully to two real RS232 ports? If you need to, did
you pair the two modules?

Try interconnecting two PCs - or two RS232 ports on the same machine if
you have them. BX-24 does not use any handshaking lines for comm
(except for DTR which is used as the ATN signal to download code) but
the Bluetooth radio might need to have at least RTS active to connect.
Try strapping CTS to RTS on the BX-24 end of the radio link. If that
still doesn't work, you can use an RS232 breakout box or an RS232 signal
dongle to look at the handshaking signals and determine what's
happening.

And, since Bluetooth and WiFi share spectrum, if you are also operating
an active WiFi link to the machine and the Bluetooth and WiFi antennas
are close, they can interfere with each other, preventing connection or
seriously reducing throughput. If that's the case, disable WiFi
temporarily to test Bluetooth. They can coexist with care. Tom
Tom Becker
--... ...--
GTBecker@GTBe... www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700


> > ... having some troubles using a bluetooth serial adaptor to make my
>connection to Com1...
>
>Are the Bluetooth modules in cable-replacement mode? Can you connect
>the modules successfully to two real RS232 ports? If you need to, did
>you pair the two modules?
>
>Try interconnecting two PCs - or two RS232 ports on the same machine if
>you have them. BX-24 does not use any handshaking lines for comm
>(except for DTR which is used as the ATN signal to download code) but
>the Bluetooth radio might need to have at least RTS active to connect.
>Try strapping CTS to RTS on the BX-24 end of the radio link. If that
>still doesn't work, you can use an RS232 breakout box or an RS232 signal
>dongle to look at the handshaking signals and determine what's
>happening.
>
>And, since Bluetooth and WiFi share spectrum, if you are also operating
>an active WiFi link to the machine and the Bluetooth and WiFi antennas
>are close, they can interfere with each other, preventing connection or
>seriously reducing throughput. If that's the case, disable WiFi
>temporarily to test Bluetooth. They can coexist with care. >Tom >
>Tom Becker
>--... ...--
>GTBecker@GTBe... www.RighTime.com
>The RighTime Clock Company, Inc., Cape Coral, Florida USA
>+1239 540 5700 >
>
thank you for your suggestions. the two devices are paired and i have established communication between two PC's with them. They worked for a connection that i had with a Basic2 stamp as well. it just seems to be the BX24. i have connected CTS to RTS. i dont think that i have an active WiFi link . i don't have an RS232 breakout box, how would i set up an RS232 signal dongle?

Marcy



> ... They worked for a connection that i had with a Basic2...

Maybe it's just ATN signaling, then.

With hard cabling, try writing and running a simple BX-24 program that
simply sends RS232 data at 19200, maybe a loop count. Once that works
with a cable, insert the Bluetooth modules. If you see good data,
modify the program to echo received RS232 data and try that through
Bluetooth.

If that works but you still can't control the BX-24 from the IDE through
Bluetooth, my guess is that the modules do not control DTR/ATN quickly
enough to satisfy the BX-24. Still, that only affects development; ATN
is not normally required to be connected in an application, so you can
probably develop with a cable and operate with Bluetooth. Tom
Tom Becker
--... ...--
GTBecker@GTBe... www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700


"..try writing and running a simple BX-24 program.."

thanks, I tried that and i am still having problems. I even tried using the hello,world program....it worked with a cable but not the serial adaptors. i can have a continuous stream of data coming in with a cable but as soon as i insert the bluetooth devices, the connection goes completely silent. i'm wondering if this is just one of those odd incompatibilities. Do you know of any cases of someone using a Promi SD202 bluetooth device with a BX24? thanks

Marcy



> ...it worked with a cable but not the serial adaptors.

Do the adapters connect? Do you see a CONNECT message at the PC or does
DCD go high at the PC?

How is the Bluetooth module powered? Tom
Tom Becker
--... ...--
GTBecker@GTBe... www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700



>How is the Bluetooth module powered?


the modules have connect lights and i've been testing with them both being powered through USB ports. i've also tried one with a battery pack.
when i connected two PCs with them they were both powered through USB ports. Marcy



> ... I've also tried one with a battery pack.

I guess I didn't ask specifically enough.

How did you power the Bluetooth module when it was connected to the
BX-24? And when it worked with the Basic Stamp2?

Did you see a connect light when on the BX-24? If you did, the BX-24
should have seen data sent from the PC end. Was the speed correct? Tom
Tom Becker
--... ...--
GTBecker@GTBe... www.RighTime.com
The RighTime Clock Company, Inc., Cape Coral, Florida USA
+1239 540 5700