# ROBOTC.net Blog

ROBOTC News

## Student POV: Robo 500 Challenge

Hi, we’re Alexis and Noah, two eighth grade students at Hopewell Memorial Junior High School. Earlier this week, we did the Robo 500 challenge. To write the programs, we used the recently released ROBOTC Graphical software for the VEX IQ. The goal of the challenge was to complete two laps around a Vex IQ storage bin.

We completed the challenge by using timing and degree measurements. The first step was to get the robot to move forward. For this, we would use a basic motor command.

In ROBOTC Graphical, it gives you the option to choose the values in which you want your motor to run by, such as time and rotations. In this challenge, we chose time.

From there, we experimented with different time values until we found the timing that was needed to finish the side of the challenge before the turn. Through testing, I found that 3.7 seconds covered the distance needed.

Now, what was left was the largest challenge of the program, the turn. Timing a turn can be challenging on seconds alone. So, I used degree turns. I started with a 180 degree, which brought me around about 45°. Due to the drift of the robot when it moves forward, I had to make the turn slightly less than double the 180° turn. I settled on a value of 300°.

Once the values were established, the rest was just repeating the commands so the robot would go around the whole box. Here is an example of my final program.

We were then thinking about how the turns were a hassle with trial and error, and contemplated a better way to turn. So, we decided to use a gyro sensor to have the most accurate turns possible.

To start out the program we had to reset the gyro sensor so the sensor could record the degrees from zero.

From here we moved forward to the end of the course for time, and we moved forward for about four seconds. Then we used a while loop. A while loop is set to check a condition and while the condition is true, it performs what is inside of the curly braces of the while loop. In this case the condition is while the gyro sensor value is less than 90 degrees.

We would then repeat these actions until the robot has made two full laps around the course. Here is the program for one lap. To do two laps I would just repeat this program again.

We were able to finish our programs efficiently in a short amount of time due to the design of the new graphical programming. This new design enables you to drag over commands from the function library; such as, moving forwards and backwards, turning, and sensor commands while avoiding the hassle of painstakingly typing each command. This reduces the time spent on each program and allows us to speed up the pace at which we program, and we are able to complete challenges in a shorter amount of time.

To the left, we have an image of the function library and a depiction of what would happen if you dragged a command into your program. The command would line up with the next available open line and would give you options as to what values you wanted to program your robot with.

————————————————————

If you’re a student who would like to contribute to the blog, let us know at socialmedia@robotc.net.

Written by Cara Friez-LeWinter

March 26th, 2014 at 7:30 am