Quick RS232 Connection Question

[Speakerguy]

I have an RS232 female connector on my PCB. Do I connect the TX from the PIC (through the RS232 transciever chip) to pin 2 or pin 3? I want to be able to hook a serial cable up to it and have it talk to hyperterminal with no need for a null modem or gender changer or whatever.

 

[saturn1bguy]

I have an RS232 female connector on my PCB. Do I connect the TX from the PIC (through the RS232 transciever chip) to pin 2 or pin 3? I want to be able to hook a serial cable up to it and have it talk to hyperterminal with no need for a null modem or gender changer or whatever.

I know Hyperterminal as a program, not as a hardware device. And, as far as cables go, I can grab through a box of serial cables and pick out any of four or five variations, depending on what it was made to do

If you already have your serial cable handy, see if it swaps pins 2 and 3. Then, depending on what your cable will hook to, say a PC *running* Hyperterminal, check the voltage on pins 2 and 3. Whichever pin is sitting at -5V or -12V (with respect to pin 7 or 5, depending on whether it's a 25pin or 9pin connector, respectively), that's the pin it's transmitting on. Make sure YOUR xmit via YOUR cable doesn't clash with it.

(However, if you're doing it by the book, pin 2 is xmit for a DTE, pin 3 is rcv. And they're swapped [as are many other pins] for a DCE [modem]. A straight-through cable is used between DCE and DTE, and a null-modem cable between DTE and DTE, as there's no modem in the loop. Curiously enough [for the non-initiated], the latter cable also works just fine for two modems, despite the name.)

 

[Gayan Soyza]

Connect PIC TX pin to MAX T1 IN (11) & Connect PIC RX pin to MAX R1 OUT (12).

MAX RS1 out to RXD pin (2) in female connector
MAX RS1 in to TXD pin (3) in female connector