Serial Communication

Community PCB Design
1

Can anyone explain how to connect RS232 DB9 male connector to a PIC via max232 level converter??

I have d circuit diagram for a female converter… Is it same as the female converter?

2

The pin outs are the same for male and female connectors.

-Bill

3

The pin no’s of male connector is counted left to right.

The pin no’s of female connector is counted right to left.

So that is not same i feel. Can u pls post a circuit diagram???

4

While the contacts are arranged in a different order between male and female dsub connectors, you will see that when they are mated together, pin 1 goes to pin 1, pin 2 goes to pin 2, and so on. This means the pin out is the same for a male connector as it is for a female connector.

Since you have a diagram for the female dsub, wire the male one the same way.

-Bill

5

You still need to watch out for the old DTE/DCE issue (the pin is called RXD, but from who’s point of view :slight_smile: ). Make sure one device is transmitting on 2 and listening on 3 while the mate transmits on 3 and listens on 2. The minimal connections needed are pins 2, 3, and 5 (ground).

/mike

6

N1IST is correct, pins 2, 3 and 5 are your minimal connections needed:

Look at it this way…

FEMALE     MALE
TX 2 >>>> RX 2
RX 3 <<<< TX 3
GND <<>> GND
7

The [sparkfun tutorial may help. It is for the atmega, but the max232 circuit will be the same-- just consult your datasheet to connect the appropriate RX/TX pins of the micro-controller.](Beginning Embedded Electronics - 4 - SparkFun Electronics)

8

The mnemonic I always used is a DTE Transmits on pin Two of a Twenty five pin connector.

Hey, it worked for me :slight_smile: Just remember that pins 2&3 are reversed on 9 pin vs 25 pin.

rpcelectronics:
N1IST is correct, pins 2, 3 and 5 are your minimal connections needed:

Look at it this way…

FEMALE     MALE

TX 2 >>>> RX 2
RX 3 <<<< TX 3
GND <<>> GND