Uber-easy DIY USB ALDL Cable

[phonedawgz]

The diagrams for making a DSM cable start with a Rs232 serial port board and then they add the diode and resistors. Actual RS232 ports operate at a + or - 15v. The cable you show is for a TTL level RS232 port. That operates at only +5v and 0 or +3.3 and 0. I don't think it will work for you. Look for a board that terminates in a DB9 connector. A board terminating in a DB9 shouldl have the actual RS232 voltages on it. Perhaps something like this on - http://www.ebay.com/itm/USB-2-0-TO-R...item5d4e74f15a

For your reference - RS232 voltages - https://en.wikipedia.org/wiki/RS-232
TTL - https://en.wikipedia.org/wiki/Transi...ansistor_logic