RS232 Port on the Professional Development Board

JohnBF

I'd like to set up a second basic stamp in the breadboard area of the Professional Development Board. Is it possible to use the PDB's second RS 232 port to communicate with a computer to program the second stamp? Will it hurt to go through the MAX232E? The documentation calls for connecting the Stamp pin 3 to the DB-9 pin 4, but the PDB leaves the DB-9 pin 4 unconnected. Any way around this?

Thanks.

/John

allanlane5

Yes, this will not work. You'll need a DB-9 with some jumpers to connect to the second BS2.

The problem is, the BS2 has on-module transistors that do the level shifting for the programming. Thus you don't want the MAX232 in there, and it probably won't work with the MAX-232 in there. Also, those 'level shifters' provide for an echo from the BS2 back to the programming device, which the MAX232 won't supply.

JohnBF

I suspected as much - thanks very much for the explanation. They have a nice DB9 breadboard adaptor at winfordeng.com, so that should be nearly as neat and convenient.

/John