Final Product - Fire Fighting Robot

Here are a few pic of the final product of Pat and I fire fighting robot complete with sensors, chassis, and mechanism ti extinguish flame.

Programming VEX (sneak peak)

Here is a sneak peak at Pat's and I's code for our fire fighting robot :)

!!!!!!!!!!TOY HACKING!!!!!!!

Electronic 10 Project 1: Toy Hacking

Originally I wanted to take my Oral B pulsar tooth brush and convert it into a scaled down torpedo. I choose to make a model torpedo so i can later use the same base for another project; I essentially wanted to kill two birds with one stone and same myself time and effort. Unfortunately my old toothbrush did not have a motor i could have used to make my torpedo :(

So instead i decided to build my torpedo from scratch! I believe by building my circuit from the ground up i will better understand how and why the components are used. I have separated my torpedo toy hacking project into 3 parts.

Part 1: Circuit

Parts list:
(1) PICAXE micro controller
(1) momentary button
(x) necessary resistors
(1) LED
(2) transistors
(1) back EMF suppression diode
(1) D/C motor
Let me give a brief explanation for a few items. the micro controller is necessary because i wish to have an LED allowing me to be able to check the completion of the circuit. The momentary button will be mounted in the tip of the torpedo so when it hit something it will stop the program and motor.

Part 2: Code

symbol motor = 1

main:
readadc 4,b0 sertxd("msg",#b0,cr,lf)
pause 1000
if b0 >100 then motoron
if b0 <100 then killswitch
goto main

motoron:
high motor
goto main

killswitch:
sertxd("kill",#b0,cr,lf)
low motor
end

Above is the code i wrote for my micro controller PICAXE. The logic of the program is to continually have power fed to the circuit until the momentary button is activated. Once the momentary button is activated the micro controller will execute 'killswitch' which kills all circuit protocol and power to the entire system.

Part 3: Mechanics

I havent settled on a tube to mount all my components in yet. Originally i wanted to mount all the components into a cigar tube, however discovering that i will need to have two separate power sources(one for the micro controller and one for the motor) and an added safety measure compartment to keep water away from all the electronics, i had to re-think the final product. Currently I'm leaning towards a fortified piece of plastic pipe, but i'm also investigating other options like different types of metal tubes. I have pictured right now is how i will be attaching the drive shaft to the motor as well as the propeller. My "universal" joint is plastic tubing that fits snugly around the drive shaft and the D/C motor shaft. I also use the same plastic tubing to ensure a tight around my drive shaft propeller. For the portion of the drive shaft that will pass through the hull to water i have obtained a hollow shaft that fits snug around the drive shaft. The fit is almost bearing like so i think with a little grease in side the tube PLUS the safety compartment that will separate the water from the electronic compartment.

******UPDATE******

I have ran into a problem with my circuit which requires my to have two power sources. I have investigated using capacitors in my circuit but considering i'm looking to running my D/C motor with a volt load of at least 5 volts, it's best if i just install a separate power source.

Flame Sensor - hot, Hot, HOT!

For the Fire fighting competition that will be held at the end of this class, I will need to make a infrared sensor. I will an i.rLED and an 180k resistor and since i will be integrating all of this into my VEX square robot that was designed by my partner Pat, I will be also be using a VEX extension cable to plus into the digital port. My i.rLED looks something like this. i choose a high resistance because i wanted to make sure that when i integrated the sensor with the VEX, i wanted to makes sure a value will be read. After I assembled all my parts I shrouded the LED with some heat shrink to make a funnel like contraptions, so pesky extra light from other areas doesnt confuse the light. Here is what the final product looked like.

LiLo and Sensors (aka Micro controller and Analog sensors)

Thus far LiLo is very useful. I can use her to do automated things like run a program. She can power relatively large output devices. She can even accept analog sensors! Now it's time to see if she can accept a digital sensor. The difference between a digital sensor and an analog sensor is analog supply values of Zero or One. On or Off. Yes or No. Digital sensors supply values in between giving the option of maybe. Here is a picture of a circuit i made with LiLo that has a light sensor connected. As long as the sensor supplies LiLo with a High value of my choice, the Red LED will remain on. When the sensor is covered up, which causes the sensor to supply LiLo with a small or little value, the Red LED will turn off and the Green LED will turn on. Here is a before and after pic of the circuit in the works.

LiLo and Transistors

Today I learned how to drive a relatively large output device via LiLo. LiLo can drive an LED off one of her pins because she doesnt allow some power to pass through her legs to the device. However, If i wanted to drive a slightly larger output device that require more power I would need to integrate a transistor into the circuit. How I understand to do this is, LiLo gives a very small amount of power off her leg to power a transistor. The transistor then has a gain on it that amplifies the power beyond that point. The power then is enough to supply a D/C motor, or say an incandescent Christmas tree bulb, with the necessary voltage to work. Here is LiLo and a TIP41 transistor working to power said tree blub.

Disect My Toy - Problems Arises :(

For the midterm project for Mechatronics I will have to alter a toy and make it do something else other than what it was intended to do. I searched around on the internet and found a forum where hobbies turned electric toothbrushes into torpedoes. One of my friends had an old CVS Pulsar electric toothbrush he didnt want, so I blessed enough to not have to spend money on that component. Everything else i need to make a torpedo was already given to me from my class, or i had in possession. Here is a snap shot of what I found inside the toothbrush.

There was some pretty neat things that i didn't know about when i opened it up. It cam with a 2.5 volt capacitor, and inductor which allowed charging to happen, and the prize i was really after - motor.

Unfortunately the motor was not what i hoped it to be. The motor was occilating style and did not do full rotation. Right now, my midterm project is a bust and i need to come up with a new plan if i plan to do well in this class, as well as complete my side project for my torpedo.