ANDROID 1: Introduction to Algorithms

Teaching Tips:

1. Before the lesson starts, demo this code:

ActivityMain

forwards = (Button) findViewById(R.id.bt_forwards);
forwards.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
sendBuf_byte[4] = 1;
sendBuf_byte[5] = 2;
sendBuf_byte[6] = 0;
sendBuf_byte[7] = (byte) (300 / 256);
sendBuf_byte[8] = (byte) (300 % 256);
sendBuf_byte[9] = 0;
sendBuf_byte[10] = (byte) (300 / 256);
sendBuf_byte[11] = (byte) (300 % 256);
sendBuf_byte[23] = (byte) (0x03);

sendByte(sendBuf_byte);
}
});

left = (Button) findViewById(R.id.bt_left);
left.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
sendBuf_byte[4] = 1;
sendBuf_byte[5] = 1;
sendBuf_byte[6] = 0;
sendBuf_byte[7] = (byte) (300 / 256);
sendBuf_byte[8] = (byte) (300 % 256);
sendBuf_byte[9] = 0;
sendBuf_byte[10] = (byte) (300 / 256);
sendBuf_byte[11] = (byte) (300 % 256);
sendBuf_byte[23] = (byte) (0x03);

sendByte(sendBuf_byte);
}
});

right = (Button) findViewById(R.id.bt_right);
right.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
sendBuf_byte[4] = 1;
sendBuf_byte[5] = 3;
sendBuf_byte[6] = 0;
sendBuf_byte[7] = (byte) (300 / 256);
sendBuf_byte[8] = (byte) (300 % 256);
sendBuf_byte[9] = 0;
sendBuf_byte[10] = (byte) (300 / 256);
sendBuf_byte[11] = (byte) (300 % 256);
sendBuf_byte[23] = (byte) (0x03);

sendByte(sendBuf_byte);
}
});

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="forward"
android:id="@+id/bt_forwards"
android:layout_centerVertical="true"
android:layout_alignLeft="@+id/txtStatus"
android:layout_alignStart="@+id/txtStatus" />

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="left"
android:id="@+id/bt_left"
android:layout_centerVertical="true"
android:layout_alignLeft="@+id/txtStatus"
android:layout_alignStart="@+id/txtStatus" />

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="right"
android:id="@+id/bt_right"
android:layout_centerVertical="true"
android:layout_alignLeft="@+id/txtStatus"
android:layout_alignStart="@+id/txtStatus" />

private Button forwards;
public static byte[] sendBuf_byte = new byte[28];

private Button left;
public static byte[] sendBuf_byte = new byte[28];

private Button right;
public static byte[] sendBuf_byte = new byte[28];​

This code makes the car controllable using your phone. It can go forward, left, right.

2. Next, talk about the Autonomous cars currently on the market. Have any of the sudents seen these cars before?

3. Here are some possible answers to Question 1: 

a. What to do at a green light.

b. What to do when it senses another car in front of it.

c. When to turn on the headlights.

Teaching Tips:

At this point the teacher should do the PB&J experiment as outlined here:

1. Bring a loaf of bread, a jar of peanut butter, a jar of jelly and a butter knife to class on the day of the lesson.  (Components for other sandwiches and food could work too, but PB&J is simple and cheap)
2. Put the students into small groups and tell them to write step-by-step instructions for making a PB&J sandwich.  
3. Have one group read their instructions aloud, and act them out exactly.  EX: if step one is “take a piece of bread and put some peanut butter on it” take a piece of bread and set the whole jar of peanut butter on it.  
4. After you act out the first set of instructions, have the students revise their lists to be more specific.
5. A successful list will look something like this:

   1. Take two pieces of bread out of the packaging, and set them on the desk.  

   2. Open the jar of peanut butter using a twisting motion with your right hand

   3. Set down the peanut butter jar, pick up the knife

   4. Put the knife in the jar, and take it out again

   5. Swipe the knife across one piece of bread

And so on.

Teaching Tips:

What does this code mean?

forwards = (Button) findViewById(R.id.bt_forwards);
forwards.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
sendBuf_byte[4] = 1;
sendBuf_byte[5] = 2;
sendBuf_byte[6] = 0;
sendBuf_byte[7] = (byte) (300 / 256);
sendBuf_byte[8] = (byte) (300 % 256);
sendBuf_byte[9] = 0;
sendBuf_byte[10] = (byte) (300 / 256);
sendBuf_byte[11] = (byte) (300 % 256);
sendBuf_byte[23] = (byte) (0x03);

sendByte(sendBuf_byte);
}
});

Lines No.4 to 12 are for contents of setting variable values to control the ALTINO motor. The function sendByte on the line No.14 is for sending the value saved in the buffer to ALTINO through Bluetooth communication.

Emphasize that most of their answers make logical sense, but the robot is like a toddler.  It only knows a few words and phrases, and it’s easy to put things in an order it cannot understand.

Teaching Tips:

Share the students' answers with the class. If time is allowed, have a quick discussion about what went well and what could have been done differently better. 

Question 1: Check the concepts you understand.  
This is the students' self-assessment of their understanding of the material.  You will see a bar graph once all the poll answers are submitted.  

Question 2: What is an algorithm?
An algorithm is a set of (specific) rules a computer follows to complete a task.  (Anything similar to this answer is correct.)

Question 3: What was the coolest thing you learned today?
Any answer will do here.  If time permits have a short discussion with students about their answers.


AFTER CLASS
Store Student Files
Put the student files on a thumb drive or store them in some way so that the students can continue working on their project in the next lesson. 

Pack Up Hardware
Turn off the robots and computers and pack the robots in the transport case accordingly.