Magic Finger input device is a camera on your finger tip

What if we could do away with mice and just wear a thimble as a control interface? That’s the concept behind Magic Finger. It adds as movement tracking sensor and RGB camera to your fingertip.

Touch screens are great, but what if you want to use any surface as an input? Then you grab the simplest of today’s standard inputs: a computer mouse. But take that one step further and think of the possibilities of using the mouse as a graphic input device in addition to a positional sensor. This concept allows Magic Finger to distinguish between many different materials. It knows the difference between your desk and a piece of paper. Furthermore, it opens the door to data transfer through a code scheme they call a micro matrix. It’s like a super small QR code which is read by the camera in the device.

The concept video found after the break shows off a lot of cool tricks used by the device. Our favorite is the tablet PC controlled by moving your finger on the back side of the device, instead of interrupting your line of sight and leaving fingerprints by touching the screen.

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Fingertip heart rate monitor

[Embedded lab] has a nice tutorial on building your own heart rate monitor. The monitor works by shining infrared light into the fingertip and looking at the changes in the reflected infrared signal caused by a heartbeat.  The IR detector produces a very small AC signal so a couple of op-amps are used to filter and amplify the signal. The output of the filter circuit is then read in by a PIC16F628A, which counts the beats and displays it on a seven segment display.  This might be a good project to try if you’ve got your microcontrollers down and you are looking to learn some analog electronics. Its noted at the end that the two main problems with building a circuit like this are going to be cross talk and adjusting the filters. The infrared diode and receiver should be close to each other to allow maximum reflection but you also need to make sure that you don’t allow the emitter to shine directly into the detector because the reflected light will be drowned out by the bright emitter.

[via make]