I think that the NXP LPC11U2x based boards with on-board USB don't require the second interface chip. I haven't implemented it yet, but they allow direct USB pr

I think that the NXP LPC11U2x based boards with on-board USB don't require the second interface chip. I haven't implemented it yet, but they allow direct USB programming via the same kind of system. http://mbed.org/platforms/mbed-LPC11U24/ http://mbed.org/platforms/mbed-LPC11U24/ The chip itself is under $5, so if you're implementing it yourself I think it comes in pretty cheap. You still need two USB ports though, which for me seems pretty irritating to explain to a customer I'd end up integrating it for. The best I can think of is to have a USB port for the interface, and then have a hidden internal USB port that you have to take off the case to access for reprogramming the firmware. That's ugly though, compared to the Arduino style where you can use the same port for both.