Tip #1 for Troop 77 Robotics Merit Badge

I am going to assume building the Five Minute Bot and adding the ultrasonic sensor was a no brainer.  The hardest part was finding 6 good batteries.

So.  Where to begin.  Well, you can actually use some math just to see that there is a reason you learn this stuff.  We call recall that Circumference = Pi * Diameter.  LEGO is kinda twisted and they actually put the diameter on the rubber tire.  In this case, the subject tire is a 56mm diameter.  So, some simple math tells you it is approx 176mm circumfrence.  So, how many of those fit into a meter?  Basic quick math.  You have to do that.  But, fractions of rotations gets messy when you have a much better tool at your disposal.

DEGREES!  Yup, you can control your robot by telling it how many degrees to go and get VERY accurate results vs. just random guessing.  So, we all know there are 360 degrees in a circle (rotation) so how many mm are there in a degree?

So, now you have this silly number but, you only have to use it ONCE.  Although the true number is smaller, let's just pretend it is .5mm.  If 1 degree turn of the tire is .5mm, how many degrees do we need to travel to complete 1 meter?  1 meter is 100 cm.  Or, 1,000 mm.  My math tells me 2,000 degrees.

In short, having demensions, math formulas you can figure a lot out before you even program.  This is helpful when an engineer needs to design something to explore the surface of Mars.  Too far out?  Did you know that Trinity College in CT is the center for developing robots to fight fires and reduce the risk to Firemen?

To demonstrate.  You should do the math.  But, if you want to travel 1 meter with 56mm diameter tires, you need to program the motor to go 2,045 degrees.....you just might find it traveled 1 meter.

Yup, all that math you learn can be used in the real world.  Let's hope I did it right!

Next:  Simple blocks.  You want your bot to move straight.  You want to use MOVE blocks when you want to make your bot go straight.  That is because the MOVE block makes sure both wheels turn the same amount.  Motor blocks are for single motor driven items. If you want to learn more see this YOU TUBE video.  Go to 6:55 if you want to get to the key point.

With this and other tips, you should be able to easily get to the soda can with your first program.

Good Luck!