Soldering issue for RS232 Serial connection

I am trying to make a cicuitboard for my circuit which is prototypes on the breadboard.

There are serial port Tx and Rx pins from a PIC16f688 which i use to interface to the PC. On the breadboard these work fine, when i soldered these onto my board the trasmission has a lot of errors. I have checked the connections and I am using wires to solder these onto the board.

Is there a recommended way of soldering when a serial transmission is concernced. What can be done to prevent these errors.

Best Regards and TIA.
Sumit

You have to use a MAX232 to get the correct voltage levels, if you want to connect your PIC to a RS232 port.

Hayato said:

You have to use a MAX232 to get the correct voltage levels, if you want to connect your PIC to a RS232 port.

Click to expand...

Depends on the serial port. I have a Dell Laptop with a serial port and it reads CMOS 0-5V levels just fine.

Besides, if I'm interpreting the OP's post correctly, this used to work while his circuit was on a bread board, but it began not working properly when he built a permanent circuit.

My guess is that there is a missing ground between the computer's serial port and the circuit. The PIC Vss pin has to be wired the computer's ground (pin 5 on the serial port?).

If it is connected the same on both the breadboard and the soldered board then it could be your solder joints. It may be worth reading https://www.electro-tech-online.com/threads/basic-soldering-desoldering-guide.55/

Mike.