Flex Type and Sign

Using flex circuitry, individual accelerometer / gyroscope units mount on each finger and sense motion to interpret signing or air typing.

Description

This project is for the Flex Circuitry Contest. Using flex, an accelerometer / gyroscope can be attached to each finger (just one hand to start). A microprocessor mounted on the back of the hand collects the data and determines the position and rotation of each finger. The goal is to recognize typing or signing (as in ASL, not handwriting).

Although this is first a hardware project, there will be a large software component to do the calculation of position and the recognition and interpretation of the motions.

The two pictures show the feasibility of using flex circuitry. Note the large radius of the bends when the finger flexes. These should insure the life of the sensor connections. See the details below.

Details

The accelerometer / gyroscope unit is the LSM6DS33 from ST Microelectronics. It's in a 3mm square SMT package and only needs a 100nF cap. Communication is by I2C bus. Various ARM microprocessors could be used to process the data, but a Teensy 3.6 will be used initially. The Teensy is still small enough to fit on the back of the hand and not impede motion.

Here is a sketch of the concept. I've slightly simplified it to a narrow strip, but the idea is the same.