Dear jong kung
I forgot to mention, although a true RS232 works at + and - 12 volts, if both sides agree, you can also use the protocol at +5 and 0 volts....which is where it is before it gets boosted in most computers anyway!!
The PICAXE cable shuts a standard RS232 signal down to 0-5 volts for the chip via the two input resistors near to the chip.....
Which is why the finished cable only costs 2.50 UK Pounds, the USB to RS232 cable costs only 10 UK Pounds......that is really, really cheap!!!!
The chips have always got a pin for RS232 In and one for Out, but you can also use the Out pin for other jobs as well if not needed, via your program......
Greetings from
Andy Mathison
