This is one I built for a computer with an RS232 port I left out the USB to Serial chip and replaced it with a max3232 buffer it works with USB to RS232 cables so my two old laptops one with RS232 port the other 2 USB ports can use it, with power coming from the target it always has the correct voltage for the device with no drain on the laptop and very quick with program loading.
http://www.tuxgraphics.org/electronics/200510/article05101.shtml
Regards Paul
↧