Electric Imp imp API usb.configure() example

basic.usb.device.nut

function processUSB(type, details) {
    // Function called in response to a USB bus event
    switch (type) {
        case USB_DEVICE_CONNECTED:
            local descriptors = details.descriptors;
            server.log("USB device " + descriptors.product + " connected at speed " + details.speed + "Mbps");
            server.log(format("USB = 0x%04x", descriptors.usb));
            server.log(format("class = 0x%02x", descriptors["class"]));
            server.log(format("subclass = 0x%02x", descriptors.subclass));
            server.log(format("protocol = 0x%02x", descriptors.protocol));
        
            server.log("Searching for driver...");
            if (getDriver(descriptors.vendorid, descriptors.productid) == null) {
                // USB device not recognized
                server.log("Incompatible USB device connected — please remove");
            } else {
                // USB device is supported by your device
                server.log("USB device driver loaded");
            }
            
            break;
            
        case USB_DEVICE_DISCONNECTED:
            server.log("Device at " + details.device + " has disconnected");
            break;
            
        case USB_TRANSFER_COMPLETED:
            server.log("Interaction with USB device at " + details.device + " has completed");
            server.log(details.length + " bytes transferred");
            break;
            
        default:
            server.log("Unknown bus event");
    }
}

function getDriver(vendorID, prodID) {
    // This is a stub for a full driver locator. A fuller implementation 
    // would check the connected device’s Vendor ID and Product ID 
    // against known values and on a match load the correct driver class.
    // For now it returns a fail condition: null
    return null;
}

// START
hardware.usb.configure(processUSB);
server.log("Please connect a compatible USB device to this unit");

FYI - I think there are a few bugs here... See the minor updates I made at https://gist.github.com/deldrid1/282cc63e8a8ae9cadb3b56416e3df5b2