Sensors and Actuators provide super powers to kids wearing e-NABLE assistive devices such as artificial hands.
Just to keep you up to date, I will be working on fingertip force and temperature sensors as part of this effort. I will be using force sensitive resistors in voltage dividers and thermistors in voltage dividers on the ADC pins of an ATtiny84 and displaying the output on a set of transducers such as thermal outputt resistors and LEDs for the force output.
Last night I worked into the wee hours (hence sleeping until lunch) to create this circuit:
bottom center is a microphone, a high output power rail-to-rail opamp above it, some electrolytic capacitors, missing and added later is anATtiny85 processor and Adafruit neopixel, the RED power indicator LED is removed, upper left is the USB power input, not shown is the battery power input (diode ORed), and audio jack output.
The circuit is somewhat noise and very sensitive. I want to add diodes in the opamp feedback loop for commanding, increase the number ofopamp stages to three, and use a low noise dual opamp for the first two. But I am working with what I have right now.
I plan to tinker around a bit with the component values, much of which I already have done, do the processor programming, and transfer the circuit to an Adafruit PermaProtoBoard (1/2 sized as shown above) for installation with a parabolic dish on a hand.