Sensthethesia

It has been a couple of weeks and here is what I have done for our final project.

For the past couple of weeks I have been getting parts together.

I got:

5 amp,9-12V power supply.

some 5amp+ relays

lots of transistors and mosfets

found some LM34 temperature probes

3-5 Pelteir junctions

still have John Carper’s logo chip and bread board

Ryan got a windshield wiper motor from an 80′ Fairmont

Lots or wires and heat sinks, etc.

It’s a lot of junk really but it’s only cost me 13$ plus the motor ran Ryan 25$ so far.

The idea is to get all these pieces to work in concert. In order to really explain what I have done so far I need to discuss the goal of the piece.

We want to create a hanging sculpture that will be placed in the corner. This bio-mechanical sculpture is supposed to breathe. As viewers get closer to the piece, the breath rate is to change.

Stop

This problem has been the main problem that I have been addressing this week. Ideas of temperature, lights, or sound will be a later process.

Nick and Ryan have been working on a metal frame that will be used to support the structure and a system of crankshafts/hinges to make it breathe. The windshield wiper motor is to drive this action. I have been working on this part of the project: Motor control and Sensory perception (A.K.A. project Cerebellum)

I will try to explain what I have built but I have few pictures and the piece is broken up as Nick has the motor currently to measure it to build the housing inside the piece.

1. Power:The windshield wiper motor is a DC motor and it hasn’t pull more than 5 amps so it has worked fine with the power supply I had laying in my garage. To run the logo chips I will use another “wall wart” that the dog chewed up and happened to be around 6v.

2. Motor Control: With Relays I am able to cut the main power line from the motor to shut it off. A second 2-pull relay allows me to select the high and the low setting built into the windshield wiper motor. With some 2n2222 transistors, I am able to activate the relays with 5v logic inputs (logo chips).

For variable speed I have a Pulse Width Modulation circuit in line with the motor’s power circuit. Currently I have built my PWM module exactly like Keith’s example except with a 2n2222 transistor and a IRFZ44n Power MOSFETs. I am considering trying a totem pole driver. That is where I basically replace the 10K resistor in Keith’s example and use a properly current limited PNP transistor instead. This should give me a better response curve on the MOSFET as it builds it’s channel possibly giving me better thermal stability. But as is, everything is work out as it should.

3.Sensory:Here is where I left off this weekend. I had gotten 2 SRF10’s ultrasonic sensors. Unfortunately I didn’t have the time or resources to figure them out this weekend. What we want to have a 90 degree field (because the piece is in a corner) where the viewer can approach the piece and the sensors detect presence and range and change it’s breathe rate. We are thinking of projecting 2 sensor fields from each wall face of the corner. Since I didn’t have a working sensor array I just used a logo chip and a potentiometer to change the motor speed. So…depending on what input I can get from the sensors I will have either a basic PWM loop something like this with various motor tricks, conditions and cutoffs inside:

_____________________For an analog input A0 ____________________________

include ad.lib

to Powerup
config-analog-lines 1
clearbit 1 porta-ddr
clearbit 1 porta
end

to startup
loop[
setn read-ad 0
setm n / 32
setbit 1 porta mwait m
clearbit 1 porta mwait (32 - m)
]
end
_________________________________________________

OR….

_______________For a digital binary input (write/read port) from another logochip__________

to powerup

write portb-ddr 0

write portb 0

end

to startup

loop[

setn read-ad 0

setm n / 32

setbit 7 portb mwait m

clearbit 7 portb mwait (32 - m)

]

end

_________________________________________________

So….That where I am at. Here are some pictures and a very bad drawing Of what I have done. I couldn’t get a picture of it all together so the pictures don’t make sense.