CS 1020 - Lab 1 - The Sciborg

Part 1: Build a Sciborg

Build a Sciborg with worm gear drive and a front bump sensor. Here are step-by-step instructions for our model. This is just an example, so feel free to build a more interesting (and nicer) Sciborg. Test your Sciborg with the program simple.txt, which we have already downloaded to your Handy Board. Make sure the Sciborg can correctly perform "fwd-until-bump", "left-until-bump", and "right-until-bump" as commanded.

Part 2: Connect your computer to your Handy Board

To get ready to download other programs to your Handy Board, open the file CS1020.zip and save the folder CS1020 to your Desktop (either by draggin it there or by selecting "Extract all files". Once saved, open the CS1020 folder and double-click on the file "HandyLogo.jar". This will open the program "LogoChip Logo" which will let you interact with your Handy Board. If you see the message "can't open serial port", close all "LogoChip Logo" windows, check that your Handy Board is connected and turned on, and try again.

Next, open Day1.zip. For now, save the Day1 folder within your CS1020 folder. Note, however, that the files on your Desktop might get erased, so once you start writing your own programs be sure to save them in your tigercat account. To download one of the programs in the Day1 folder to your Handyboard, go to your Logo window, click on the button labeled "...", select the Day1 folder and within it one of the programs. Then click on "download".

Part 3: Experiment with light sensors and follow-line

Start by experimenting with the light sensors. Plug them into ports 0 and 1 of the Handy Board and select the analog display mode by turning the user knob past option (7). See how the values change as you move the light sensors around. Then, download the program sensortest.txt from the "Day1" folder onto the Handy Board, and experiment some more. Try to find a good distance and a good value for the threshold "black" so that the sensors can detect a black line reliably.

Next, attach the light sensors to the front of your Sciborg (you may have to rebuild it first...). Download the program sciborg.txt, and run the program "follow-line". In order to get your Sciborg to correctly follow a line, you'll have to experiment with the blackness threshold and with the height of the light sensors. Change the blackness threshold using the black+10 and black-10 menu options. Experiment to find a suitable value. Work with your Sciborg and the placement of the light sensors until the Sciborg can follow a line.

Some questions for thought and experimentation

Discuss the following questions in your group and check your answers using experimentation. (Nothing to be handed in.)
  1. What do you think would happen if the ports of the two analog sensors were reversed?
  2. What should happen if the motor ports are reversed?
  3. Reorienting the way the motors are plugged in will turn the wheels in the opposite direction. Would the Sciborg follow the line going backwards?
  4. Improving follow-line:
    Sciborg's follow-line program produces an awkward, jerky motion that succeeds in following the line, but does so without much elegance. Discuss theoretical ways of improving the line-following behavior, either by modifying the program or by modifying the robot. We'll come back to this question in a few days!