Working with USB devices in .NET

Question

Using .Net (C#), how can you work with USB devices?

How can you detect USB events (connections/disconnections) and how do you communicate with devices (read/write).

Answer 1

If you have National Instruments software on you PC you can create a USB Driver using their "NI-VISA Driver Wizard".

Steps to create the USB Driver: http://www.ni.com/tutorial/4478/en/

Once you created the driver you will be able to Write and Read bytes to any USB Device.

Make sure the driver is seen by windows under Device Manager:

C# Code:

    using NationalInstruments.VisaNS;

    #region UsbRaw
    /// 

    /// Class to communicate with USB Devices using the UsbRaw Class of National Instruments
    /// 
    public class UsbRaw
    {
        private NationalInstruments.VisaNS.UsbRaw usbRaw;
        private List DataReceived = new List();

        /// 

        /// Initialize the USB Device to interact with
        /// 
        /// In this format: "USB0::0x1448::0x8CA0::NI-VISA-30004::RAW".  Use the NI-VISA Driver Wizard from Start»All Programs»National Instruments»VISA»Driver Wizard to create the USB Driver for the device you need to talk to.
        public UsbRaw(string ResourseName)
        {
            usbRaw = new NationalInstruments.VisaNS.UsbRaw(ResourseName, AccessModes.NoLock, 10000, false);
            usbRaw.UsbInterrupt += new UsbRawInterruptEventHandler(OnUSBInterrupt);
            usbRaw.EnableEvent(UsbRawEventType.UsbInterrupt, EventMechanism.Handler);
        }

        /// 

        /// Clears a USB Device from any previous commands
        /// 
        public void Clear()
        {
            usbRaw.Clear();
        }

        /// 

        /// Writes Bytes to the USB Device
        /// 
        /// USB Bulk Out Pipe attribute to send the data to.  For example: If you see on the Bus Hound sniffer tool that data is coming out from something like 28.4 (Device column), this means that the USB is using Endpoint 4 (Number after the dot)
        /// Data to send to the USB device
        public void Write(short EndPoint, byte[] BytesToSend)
        {
            usbRaw.BulkOutPipe = EndPoint;
            usbRaw.Write(BytesToSend);       // Write to USB
        }

        /// 

        /// Reads bytes from a USB Device
        /// 
        /// Bytes Read
        public byte[] Read()
        {
            usbRaw.ReadByteArray();     // This fires the UsbRawInterruptEventHandler                

            byte[] rxBytes = DataReceived.ToArray();      // Collects the data received

            return rxBytes;
        }

        /// 

        /// This is used to get the data received by the USB device
        /// 
        /// 
        /// 
        private void OnUSBInterrupt(object sender, UsbRawInterruptEventArgs e)
        {
            try
            {
                DataReceived.Clear();     // Clear previous data received
                DataReceived.AddRange(e.DataBuffer);                    
            }
            catch (Exception exp)
            {
                string errorMsg = "Error: " + exp.Message;
                DataReceived.AddRange(ASCIIEncoding.ASCII.GetBytes(errorMsg));
            }
        }

        /// 

        /// Use this function to clean up the UsbRaw class
        /// 
        public void Dispose()
        {
            usbRaw.DisableEvent(UsbRawEventType.UsbInterrupt, EventMechanism.Handler);

            if (usbRaw != null)
            {
                usbRaw.Dispose();
            }              
        }

    }
    #endregion UsbRaw

Usage:

UsbRaw usbRaw = new UsbRaw("USB0::0x1448::0x8CA0::NI-VISA-30004::RAW");

byte[] sendData = new byte[] { 0x53, 0x4c, 0x56 };
usbRaw.Write(4, sendData);      // Write bytes to the USB Device
byte[] readData = usbRaw.Read();   // Read bytes from the USB Device

usbRaw.Dispose();

Hope this helps someone.