View Full Version : COM ports in Professional Deevelopment Board

06-06-2005, 06:34 PM
I am trying to use a COM port to·send data·from BS to PC.

There are apparently three choices in PDB: the USB COM port, the standard upload COM port and the MAX232 port.
Which is the right way to connect the Stamp to send data to a PC ?

By the way, I have realized that I cannot have both USB and upload/COM port connected at the same time.

If I use USB COM port with a SEROUT 15, would I be able to send data to my PC using the USB COM port ?

In case I use the MAX232 port which would be the right·connections to make ?
Note that I want to send data from the Basic Stamp. Is MAX232 port intented only for the SX part ?

06-06-2005, 06:45 PM
Where do you want to send the PC data - to the debug screen or perhaps Hyperterminal?

I communicate with both the debug sccreen and Hyper using the DB9 serial connector on the PDB using serout 16................

Sid Weaver
Need a bezel for your LCD?

Newzed@aol.com (mailto:Newzed@aol.com)

Jon Williams
06-06-2005, 07:06 PM
The BS2 programming ports (USB and COM) are located between the power input and Stamp socket.· You can use either (but not both at the same time!) for communication with the PC by using DEBUG or SEROUT on pin 16.· You cannot do flow control with either of these ports as they are connected to the programming pins on the Stamp.

The RS-232 DCE port on the bottom edge of the board can be used by any of the micros, and it allows you to have full control over the port.· Just use 22-guage solid wire to connect between your BASIC Stamp IO pins and the RS-232 port pins.

Jon Williams
Applications Engineer, Parallax

06-06-2005, 07:51 PM
Thanks, the USB port works well when using PIN16. In case I want to use the serial DCE port, which connections shoudl I use, all of them (RX,TC,RTS,CTS)? If so, where can I find an example of use in PBASIC ?

By the way, if I use the DCE port, the Parallax cable provided for programing/debugging is not valid, is it ?

Jon Williams
06-06-2005, 08:26 PM
It's pretty easy: You connect your SEROUT pin to TX, your SERIN pin to RX.· If you want to use flow control, RTS (request to send) is the FC pin for SEROUT, and CTS (clear to send) is the FC pin for SERIN.·

I whipped up a very quick demo that you can use while staying in the editor.· Download the program, then open a manual Debug Terminal, select the port you want to talk on and enable hardware flow control by checking DTR and RTS (see graphic).


Jon Williams
Applications Engineer, Parallax