I have decided to design my own robot based off of David Cook's "Sandwich." The main differance is that it uses a Quad Comparator (LM339) instead of a Dual- Comparator (LM393N). I could have followed the design of his and leave those pins open. Instead I used those to control ouput LEDs and the other to control the motors. I did this to take a few milliamps off the 2907A PNP transistor. (After building sandwhich, I noticed that the transistor got seriously hot and shorted out.) This will also stop the LEDs from dimming when the motors engage, although I could have just added some caps.
This robot is very rudimentary and simple and fun to make. Are you ready to get your hands dirty and create this awesome bot. Just follow the step by step instructions,
Step 1 (Getting the parts)
These are the parts you will need to create this robot. You can obtain them from your company of choice. You may choose the geared motor of your choice. I used Neng Seng motors I had laying around, but I would suggest a solarbotics gm2 or gm3 with wheels.
- 1x power switch
- 1x dpdt center off switch
- 1x LM339N
- 4x Cds photocells
- 4x 150 ohm resistors
- 4x 1K ohm resistors
- 4x PNP PN2907A transistors
- 3x green LEDs
- 3x yellow LEDs
- 2x Geared motors
- 2x 20K ohm trimpots
- 2x white LEDs
- 2x 1N5817 Schottky barrier diode
- 1x 9V battery holder
- 4x 2 pin male molex kk connectors
- 4x 2 pin female molex kk connectors
- 1x 4 pin male molex kk connector
- 1x 4 pin femal molex kk connector
- lots x kk crimp terminals
- 1x 14 pin DIP socket
- 1x blank breadboard
- Mounting hardware (screws, nuts, washers, bolts)
- tires
- body ( example: Ziploc container)
This list may sound very long for a begginer, but for the veterans reading this probably would agree with me this is a small part list.
Lesson 1
It is very important to build robots in modules. If the modules don't turn out the way you planned, they are easier and cheaper to replace than a whole robot
Lesson 2
We will be taking little bites. Try to do a lesson a day at max for those beginners out there. TAKE YOUR TIME! This is sometimes the differance between success and failure.
Lesson 3
Failure is not always bad. Edison once said that he found 1,000 ways how to not make a lightbulb and learned from his mistakes. Take note of your mistakes but do not let them put you down. If you do this you will hopefully not make the same mistake twice.
Lesson 4
Safety in robotics is like all safety, USE COMMEN SENSE. Use the tool it was meant to be used and where safety glasses when appropriate. It only takes a little peice of shrapnel to blind you.
Follows Light and Dark Lines
- Actuators / output devices: 2 geared motors
- Control method: autonomous
- CPU: none
- Power source: Consumer 9Volt
- Sensors / input devices: 4x CDS Photocells
- Target environment: indoor flat surfaces
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/hound-dog