Hello, Simon.
Unfortunately, we do not have any C code using the Maestro’s native USB. However, we do have some C++ examples in the Pololu USB Software Development Kit (SDK) for the Maestro that you might find helpful. Also, you might find it helpful to look at this thread on implementing the Get Position command in C++ using the SDK.
By the way, if you are using libusb, you can store the libusb_device_handle pointer in a global variable that gets set at the start of your program. You can find more information about the device handling and enumeration of libusb here.
- Amanda