Red Spot

Inspiration

Red Spot was created in as a complement to Feeling Blue. This robot uses an Atmel as its brain. I did not write the source code as I don't really know much about Atmels. A fellow that I was attending college with at the time wrote the line following code.

Chassis and Propulsion

Just as feeling bloe, the red spot uses the same round robot chassis from Pololu. The motors are a Tamiya Dual Motor Gearbox with Tamiya Truck Tires. The Pololu round chassis is fairly inexpensive and can make creating a robot pretty easy.

Line Sensors

The robot uses three OPB742 IR emitter/IR Photo transistors to detect the line. Three is just barely enough to successfully track a line. The sensors have a fairly limited range so they have to be placed very close to the ground. The output of the sensors is combined to get the position of the line.

Robot Brain

The robot is driven by an Atmel Atmega8-16PC @ 16MHZ. The micro monitors all the sensors and takes the appropriate action when a sensor is triggered. The algorithm is pretty basic as I never really finished the code. The is no PID loop or anything fancy like that. The speed of the motors is set from a table based on where the line is that is it.

Feeling Blue Data Sheet
Robot class	Line Follower
Size	5.1 in(W) x 6.9 in(L) x 2.75 in(H)
Weight	325 grams
Frame	Pololu round chassis and protoboard
CPU	Atmel Atmega8-16PC
Programming Language	Assembly written in the AVR Studio
Power	7.2V from a six cell Nicd battery pack. The voltage is regulated to 5V for the CPU.
Motors	Tamiya Dual Motor Gearbox.
Motor driver	L293 driven by microprocessor
Speed Control	Software generated Pulse Width Modulation.
Drive System	2WD using two motors
Tires	1.5" Tamiya Truck Tires
Sensors	Three OPB742 IR line sensors.