Lab 1: Robot Charades
Purpose of the lab
The purpose of this lab is to engage in a type of psychology. In particular, you will perform synthetic psychology (the psychology of artificial or synthetic systems). Remember that a major goal of the psychology you study is to "reverse-engineer" the principles of the human mind or brain. Like many areas of science, we do not know the correct answer when we start out and so careful experiments and crafty theories (i.e., the scientific method) are necessary to make progress. However, in synthetic psychology, the operation of the robot is designed by a human. Thus, when you attempt to reverse engineer the robot's program we can check to see if you conclusions about the psychology of the robot are correct.
Think back to your math classes... Often you do many exercise problems to help sharpen your skills so you can tackle real problems on the final test, or in your job. This lab is like a practice exercise in psychology where you can check your answer at the end!
This lab consists of a couple steps:
- Step 1: Wire up the brain
- Step 2: Allow me to brainwash your robot
- Step 3: Figure out what your robot is doing!
- Step 4: Answer some questions
- Step 5: Read
- Step 6: Answer some more questions
Step 1: Wire up the brain
To start with, check out that your servo wheel have been calibrated and are connected properly. We will do this as a preliminary robot-building exercise in class. Next you will wire up the brain of your robot! On the top of the robot on the BOEbot shield there is a patch of white plastic called a bread-board or protoboard/plugboard. Inside it are about 100 tiny holes.
These holes are places where you can stick wires, resistors, sensors, etc... to wire up electrical circuits. The advantage of the breadboard is that you don't have to solder any parts together and everything is temporary (so you can build an reconfigure things easily).
This breadboard has 17 rows of sockets. In each row, there are two five-socket groups separated by a trench in the middle. All the sockets in a 5-socket group are connected together underneath with a conductive metal clip. So, two wires plugged into the same 5-socket group make electrical contact. This is how you will connect components, such as an LED and resistor, to build circuits. Two wires in the same row on opposite sides of the center trench will not be connected.
The prototyping area also has black sockets along the top, bottom, and left
- Top: these sockets have three supply voltages for the breadboard: 3.3 V, Vin (input voltage from either battery pack or programming cable), and 5 V.
- Bottom-left: The first six sockets along the bottom-left are ground terminals, labeled GND; think of them as a supply voltage that's 0 V. Collectively, the 3.3V, Vin, 5V and GND are called the power terminals, and they will be used to supply your circuits with electricity.
- Bottom-right: The ANALOG IN sockets along the bottom-right are for measuring variable voltages; these connect to the Arduino module's ANALOG IN sockets.
- Left: The DIGITAL sockets on the left have labels from 0 to 13. You will use these to connect your circuit to the Arduino module's digital input/output pins.
Don't worry if not all of this makes sense to you yet... It will by the end of the semester!
Here's an example of a wired up circuit on the protoboard. You just plug the right components in to create the circuit. You can ignore the details on this one... it is just for illustration.
Ok, so the brain that you are going to wire up is going to be secret. I'm not going to tell you how it works just yet and try to leave a bit of mystery. If you already know a lot about electronics this may not work, but if you don't know the difference between a resistor and a capacitor (or what they do) that is GOOD! You'll be able to do the psychology without being confused by all the electronics.
Ok, so for your brain you need to identify six components and pull out a couple short wires (you should have a bundle in your robot kit). The six components are created by getting two copies of everything you see in this picture:
From top to bottom:
- (2) small orange things that say "104" on them and look like the above
- (2) white glassy things that look like the middle item
- (2) little things that look the bottom and have a color pattern of brown-black-red
and you want to wire it up to look like this:
(ignore the big round disk, the green wire, and the shortest black wire for now). Also you might move things so that the two copied circuits are further apart on the breadboard.
Don't be afraid to ask questions. When you think you have it set up, continue to part 2.
Step 2: Allow me to brainwash your robot
When you are confident your robot is wired correctly bring it to me. I will give you batteries, check the circuit, and load up a program in the brain of your robot. When you have my approval you can proceed to step 3.
Step 3: Figure out what your robot is doing!
Now is where the real lab begins!
Your job is to perform experiments to figure out what your robot is doing. What rules is it following (if any). This is the game of charades.
Step 4: Answer some questions
In your group, answer the following questions:
Q4.1: Describe at a high level the overall behavior of your robot. Is it random? Is there some particular pattern to the behavior that you notice?
After you've CAREFULLY switched the cable, reconnect the battery pack and power up the servos. What has changed about the overall behavior of the robot (i.e., the description you provided in Q3.1)? How would you describe the robot now?
Step 5: Read
Please read the assigned sections from the "Vehicles" books posted on the course website over the weekend.