SNS-FINGERPRINT is optical fingerprint sensor which will make adding fingerprint detection and verification very simple. Inside there is DSP chip that does the image rendering, calculation, feature-finding and searching. You can teach the sensor for fingerprint images and up to 1000 images can be stored in the internal Flash memory. There’s a red LED in the lens that lights up during a photo so you know its working. In image search mode the sensor compare the current scanned image with the stored database and if images match it sens index number of the stored image which match the current scanned fingerprint.All communication is done by UART.