A very easy and cheap option is to get the ready made ftdi USB to TTL level serial converters (from their online shop) and a simple AVR ATtiny2313. This part has 4 PWM's for driving the gauges, a UART to receive values for the gauges and some spare IO to flash a backlight LED. The FTDI USB adapters come with a virtual COM driver for Windows so you can control your gauges from Python, VB, Java, C++ or whatever you feel comfortable with!
Antoon
Seems a waste when you can do what you want in a single SAM7S321. There is easy to use USB CDC S/W which will give you that virtual COM port.
-- Best Regards, Ulf Samuelsson This is intended to be my personal opinion which may, or may not be shared by my employer Atmel Nordic AB
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