This PIC microcontroller based wind gauge interfaces with USB. It is still a work in progress but looks to be almost complete.
“There are various methods of measuring the speed of a wind. With this equipment, a hemispherical window cup is rotated and the method of measuring wind velocity at that number of rotations is used. The measured number of rotations is sent to a personal computer with a USB interface, and wind velocity is displayed on a screen.
Serial interface is used for the interface of USBN9604 and PIC of the USB driver.
USBN9604 is equipped also with the parallel interface in addition to serial interface. Since high-speed transmission is unnecessary in the case of this circuit, the serial interface with few signal wires is used.
This is the interface called MICROWIRE/PLUS. With this interface, four lines, CS, SK, SI, and SO, are used. This mode is set up, when MODE1 is made into H level and it makes MODE0 L level.
An INTR line is a signal wire for the interruption control.
Since the signal wires for parallel interfaces (D1-D7) are not used in this circuit, they are grounded in order to avoid the bad influence to the circuit.”