problem with testing max232 circuit

[mehregan]

I has used max232 for connection between PIC16F877a and PC bu I can't receive data, so I tested my level converter circuit separately. I used echo technique for testing it bt unfortunately I can't see double word i hyper terminal. I checked my circuit and it is as same as conventional MAX circuit
please help me, I can't find the problem.

 

[bigdogguru]

Have you performed a loopback test on the MAX232?

The test can be done by tying the TX and RX lines together on PIC input side of the MAX232, then disable echo feature in hyperterminal, each character you type should appear in the terminal window.

If the loopback fails then the issue is with the MAX232. If the loopback test succeeds then the issue is either the TX and RX connections to the PIC or the code.

I would recommend posting a schematic of your design and the source code as well.

BigDog

 

[mehregan]

Thanks for your reply,
of course I used loop-back test but the favorite result wasn't archived. I used another MAX232 but the problem isn't solved. I attached the max232 circuit which i used.

 

[bigdogguru]

Your schematic is far too small to read.

What value of capacitors are you using with the MAX232? Are you operating the device at 5V?

BigDog

 

[mehregan]

The capacitors which are used in my circuit are 1uF and the schema is attached. the supply voltage is 5V.
do you know what the problem is? do you think the size of capacitors are important?

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the schema is