Step 2: Build the RS232 interface
Figure out how small you can make it.
Put all the components on a perfbaord. Place them with the circuit in mind. We don't want to add any wires to the bottom of the circuit! Se image.
Cut out the right size perfboard.
Just drag a sharp knife a few times over the row of holes where you want to cut.
Do this on both sides, then just break it in two. It usually breaks at the fault line you created.
Solder the components in place. and connect the solder points to complete the circuit.