how to send a signal to usb
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I have a output (i.e)traini8ng and testing the finger print images,if finger print matches i want to send that output to usb where i will connect ad device hardware,ai have completed till matching of fingerprint,and got an output,"fingerprint matching",now i want to send this to usb port,caan anyone guide me please
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Image Analyst
2011-10-15
I use USB devices from Measurement Computing www.mccdaq.com They have code that integrates in with the MATLAB Data Acquisition Toolbox http://www.mathworks.com/help/toolbox/daq/ref/f3-33917.html#f3-35744 . You can send or read to this device from the USB port. The device has pins that can set or read voltages to do various things with other specialized custom devices that you hook up to them, such as red or green LEDs that might indicate fingerprint "match" or "no match." You can also read toggle or pushbutton switches, turn on or off motors, digitize analog signals, or whatever you want.
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Walter Roberson
2011-10-15
You could send it to a USB controller (if you worked hard enough at it), but the USB controller would just discard it as being an invalid command.
USB is not a COM port with a different connector. USB is a packetized serial multidrop interface with a strict protocol. Each item send to the USB controller must contain a device address specifying the destination, which can be that of the USB controller or that of a device attached to the controller, such as a webcam or hard disc. A webcam would not know what to do with an output of "fingerprint matching".
One of the type of devices that can be connected to a USB controller is a virtual serial communication (COM) port. To connect to one of those, you use
instrhwinfo ('serial')
to list the current serial object names; once you have found the right name, you proceed the same way as for any other serial object; see http://www.mathworks.com/help/techdoc/ref/serial.html
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