tekromancR is a student living in Wisconsin in the United States. He is a programmer, artist, hacker, transhumanist, and general techno-fiend. He is currently going to school for neuroscience.
Tick-Tock Ton Coeur
December 26th, 2009 by tekromancr received 2 Comments »
My next project:
A gear powered mechanical heart!
. . . sort of.
Actually, it will be a wearable mechanical heart shaped heart rate display. The project is comprised of three parts.
1) The Heart rate monitoring unit.
I plan on accomplishing this with a home made pulse-oximetry unit. This works by shining high intensity IR-light through the skin and measuring the amount of returned light. Conveniently, the amount of light returned coincides with the rising and falling of ones heart rate.
2)The filtering/processing/amplification circuitry
This part I am a little bit less clear on. Obviously, I need to process the signal in such a way that the motor in step three spins ever so slightly every time a pulse-beat is detected.
3)The motor/heart/gear assembly
This is the part that is visible to the world. A motor, passed through the back of the heart shaped case, spins a gear inside, hopefully in time to the wearer’s heartbeat.
The heart shaped case (according to the seller) is 27mm, so I need to find a slightly smaller gear (preferably brass) to fit inside of it. I am guessing 18mm just to be in the safe side. Any one know where I can make/purchase such a gizmo?
I have a pretty good idea how I am going to pull steps 1 & 3 off, but my lack of electrical engineering knowledge leaves me at a loss as far as number two is concerned. If all else fails, I could just dump the input onto a lillypad arduino, do signal processing that way, and then control the motor from the arduino.
Tags: arduino, projects, steampunk
Posted under: projects
If you’re not going to use the microcontroller (and I agree, it’s overkill for this project unless you’re also planning to control a lot of other functions) then you may find this useful:
http://www.electronics-lab.com/projects/motor_light/038
Just replace the pot they show there with your photoresister that’s looking at the returned light.
Good luck! Sounds like a fun project
That is brilliant! I like that a lot, except, I want the gear to move only on one of the edges of the signal, to closely emulate the ticking of a clock. Perhaps there would be some way to only run the motor when the signal rises above a certain point. What additional circuitry would I need to add to that? By the way, how did you learn about this project?