Thread: Serial communication problem upon soldering

You need a level converter like a MAX232.

it has nothing to do with the soldering, unless its not right like the solder isnt making contact well or there is too much flux or you crossed traces or may a wire is melted somewhere and touching something eles

I am trying to make a circuitboard for my circuit which is prototyped 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.

So it works on the solderless bread board with out a max 232 right?
If it did then it was the capacitance of the board would be the only thing that could of changed if you made the circuit the same. But you need a level converter a max232 would be the easy way to go.

If he has a newer computer the voltage level may be lower some newer ones use the same
power that the usb uses. But I was thinking the same thing He may have cooked it.

The output from the PICs UART is postive logic, i.e. 1==high, 0==low.

RS232 uses negative logic where a 1 is low and a 0 is high so even if the voltage levels were being detected as high and low, the data itself would be inverted including the stop and start bits.

We are of course making the assumption it's connected to an RS232 serial port. The O/P hasn't explicitly stated that is the case, only that it's connected to a PC.