This module will show you how to email a program to and from BirdBlox and provide links to articles that describe cloud-based methods of sharing files.

If you are still learning to program your Finch, skip to the Moving & Turning module and come back here when you want to share your program.

To email a file to yourself or someone else, tap the File button in BirdBlox.

Then tap the Share button by the name of the file you wish to share.

Then select the mail icon.

Add the email address and subject. Tap Send.

To open a file from your email inbox, tap the file. In the menu that pops up, select BirdBlox (Android and Kindle) or Copy to BirdBlox (iOS). In iOS, you may need to scroll to the right to see this option. The file will open in BirdBlox!

You can connect up to three Finches in BirdBlox on iOS devices and two Finches on Android or Fire devices. This means that you can write programs that control multiple Finches!

To connect multiple Finches, tap the Connection button and then Connect Multiple.

Tap the + button and select the first Finch.

The first Finch will appear beside the number 1. Then tap + again and select the second Finch.

The second Finch will appear beside the number 2. You will use the numbers 1 and 2 to tell BirdBlox which Finch you want to use for a given block. 

When you have connected two Finches, you will notice that the blocks in the Robots menu are a little different. Each block has a new drop-down where you can select Finch 1 or Finch 2. This drop-down tells BirdBlox which Finch to use for that block.

For example, this program will move Finch 1 forward first and then move Finch 2.

Write a program that first moves Finch 1 in a square and then moves Finch 2 in a circle. Refer back to the Moving & Turning and Controlling Wheels tutorials if you need to remember how to make a square or circle.

Click Here to see example code.

Sometimes you may want your Finches to execute the same movements at the same time. For example, suppose you want the Finches to dance together! You can easily do this by duplicating a script in BirdBlox and using the when green flag tapped block.

Start by writing a program for the first Finch. For example, this program turns the first Finch to the right and then to the left.

Then tap and hold on the when green flag tapped block. You will see a pop-up that gives you the choice to Duplicate or Delete. Tap Duplicate.

This will create a copy of the whole program. Then, select Finch 2 for each block in the second program. Now your Finches will move together when you tap the flag!

Make your Finches dance together! You may notice that your Finches don’t move at exactly the same time. This is because the bluetooth connection between the tablet and the Finch can delay one robot a fraction of a second.

The Robots menu contains two encoder blocks. The Finch Encoder block measures the number of wheel rotations that the wheel has moved since it was last reset. Before the Finch makes a movement that you want to measure, you need to use the Finch Reset Encoders block. This block sets both encoder values to zero. 

As an example, this code measures the number of rotations of the right wheel when the Finch moves forward for one second. 

Try out the code above. What happens when you set the wheel speeds to -75%?

You can also make the Finch move until the right or left encoder reaches a particular value. To do this, you will need the wait until block on the Control menu. 

For example, this program resets the encoders and then moves the Finch forward until the left wheel has moved two rotations. Then the robot stops.

Try out the program above. Then modify this program to make the robot move backward for two wheel rotations.

Click Here to see example code.

The diameter of a Finch wheel is 5 cm. To find the circumference, the distance around the wheel, you multiply this diameter by ????, which is approximately 3.14. This means that for one rotation, a Finch wheel moves about 15.7 cm.

To find how many rotations it will take to move a given distance, you can divide that distance (in centimeters) by 15.7. For example, it will take about 1.9 rotations for the Finch to move 30 cm.

Write a program that uses the encoders to make the Finch move forward 50 cm. You are writing your own version of the code inside the Finch Move block!

Click Here to see example code.

You can also use the encoders to make the Finch measure a distance. For example, this program measures how far the Finch has to travel to find an obstacle. At the beginning of the program, the encoders are reset. Then the Finch moves until an obstacle is less than 20 cm away. Finally, the robot stops and displays the number of rotations that the left wheel has traveled. 

Try out the program above, then modify this program to display the distance in centimeters that the robot has moved. Hint: You will need a math block from the Operators menu. Can you modify this program to measure the distance that the Finch has to travel to find a black line?

Click Here to see example code.

The example code shows the program measuring a distance to a black line.

For this lesson, you will need large sheets of white paper and black electrical tape about 2 cm wide. Use the tape to make a black line on a white background. Avoid sharp turns; it is easier for the Finch to follow gradual curves.

To track a line, the Finch should turn right or left based on whether or not it detects the line. Let’s track the left side of the line with the left line sensor as the Finch moves clockwise around a loop. When the left line sensor is over the black line, the Finch should turn left. When the left line sensor is over the white surface, the Finch should turn right. 

Notice that this sample code uses the Finch Wheels block to turn using only one wheel at a time. This means that both turns move the robot slightly forward. As the Finch repeats the if else block over and over, it will follow the line as it turns back and forth. 

Note: As you run a BirdBlox program, the app relays commands over Bluetooth to the Finch. There is some delay in this process, and that means that you need to turn slowly to track the line.

Try out this code. You may need to adjust the line sensor threshold and the turning speed to track your line. The Display block will show you the line sensor value so that you can choose a good threshold. Remember, the Finch needs to turn slowly.

Your current code works if you want the Finch to keep tracking the line forever. But what if there is an obstacle in the Finch’s path? Then you don’t want to repeat the if-else forever. You only want to repeat it until you find an obstacle. In this case, you’ll want to use the repeat until block on the Control menu.

This loop repeats the blocks inside it until the Boolean block is true. For example, this program makes the Finch blink its beak until the Finch’s beak points up.

CHALLENGE

Use a repeat until block to make the Finch track your line until it finds an obstacle. The Finch should stop when it finds an obstacle.

Click Here to see example code.

As you build more complex programs, you will sometimes want to make decisions based on more than one sensor. For example, you might want to turn on the Finch beak and tail only if both light sensors detect that it is dark. To do this, you can use the logical operators on the Operators menu. These operators are Boolean blocks that contain spaces for other Boolean blocks. 

The and block is true if both blocks inside it are true and false if either block inside it is false. The or block, on the other hand, is true if either block inside it is true. The or block is only false when both blocks inside it are false. The not block is the opposite of the block inside it. It is true when the block inside is false and false when the block inside is true.

As an example, this program starts with the beak and tail lights off and then waits until the values of both light sensors are below the threshold. Then it turns all of the Finch lights on.

CHALLENGE

Modify your line tracking program to track the line until the Finch finds an obstacle or you place it in the Beak Up position.

Click Here to see example code.

By using logical operators and all of the control structures that you have learned, you can create complex behaviors for the Finch. You can also use multiple control structures and nest blocks inside one another to get the behaviors you want. For example, what do you think this code will do? Think carefully and make a prediction, and then try it out!

CHALLENGE

Turning left or right based on a single line sensor is the simplest version of a line tracking algorithm, but there are many variations. Write a program to implement the alternate line tracking algorithm described below. Which works better for your path?

• If the left line sensor is over white and the right is over black, turn right.
• If the right line sensor is over white and the left is over black, turn left.
• If both line sensors are over the same color, move forward in a straight line.
• For an extra challenge, modify your program to make the robot automatically restart tracking the line when you remove the obstacle!

Click Here to see example code.

The pick random block is on the Operators menu in BirdBlox. This block randomly chooses a number between the two limits given. For example, this block generates a number between 1 and 100. Each time you tap the block, it will give you a different number.

You can use the pick random block anywhere that you would use a number in your program. For example, this program sets the speed of each wheel to a random number every two seconds. Notice that each wheel gets a different random number, so the Finch will mostly turn but sometimes move straight. 

CHALLENGE

Use the pick random block to set the Finch’s beak and tail to different random colors.

Click Here to see example code.

You can also use a random number within a control structure. For example, this program will make the Finch beep a random number of times from 1 to 5.

CHALLENGE

Make the Finch play a random number song! The Finch should play a random number of notes, and each note in the sound should be random. For an extra challenge, make each note last a random number of beats from 0.1 to 1 (you will need a math block from the Operators menu).

Click Here to see example code.

To create a variable in BirdBlox, go to the Variables menu and then click Create Variable

Give your variable a name. You should choose a name that describes what your variable is. In this case, let’s name our variable randomSpeed.

Notice that the Variables menu changes once you have created a variable. You will see a block for your variable, a set block, and a change block. 

You can use the set block to assign a value to your variable. If you have multiple variables, use the drop-down menu to select the one you want to set. In this example, the loop sets the variable randomSpeed equal to a random number between -100 and 100. It resets the value of the variable every two seconds. 

To use the variable, drag the block with the variable name into your program. You can use randomSpeed anywhere you would use another number block in BirdBlox. For example, you can use it to set the speeds of both Finch motors. You can also use the Display block to see the value of the variable on the screen. Notice that in this program, only the set block changes the value of randomSpeed. The randomSpeed block just fetches this number and uses it within the Display and Finch Wheels blocks. That means you can be sure that both wheels will have the same speed.

CHALLENGE

Create three variables named red, green, and blue. Use these variables to set the color of the Finch’s beak and tail to the same random color. The color of the beak and tail should change once per second.

Click Here to see example code.

You can use the change block to modify the existing value of a variable. For example, this program sets blue to 0 at the top of the program and then adds 1 to blue each time through the loop. What will the value of blue be at the end?

You can use a loop like this to gradually change the value of a Finch output. For example, you can use blue to gradually increase the brightness of the Finch beak. You can even use a math block from the Operators menu to make the R value for the Finch beak go from 100 to 0 as the B value changes from 0 to 100. What do you think will happen when you run this code?

CHALLENGE

Modify the code above by adding another repeat block below the existing one. Use this repeat block to gradually change the value of blue from 100 back to 0.

Click Here to see example code.

Any time you need to use the same value more than once in a program, you can use a variable. Variables are also helpful if you may need to change a value later. For example, this program has two loops that use a threshold for the light sensor. One controls the Finch beak, and one controls the Finch buzzer. Depending on the amount of light in the room, you may have to adjust the value of the threshold in the future. This is a great opportunity to use a variable! Notice that we only set the value of the threshold variable once, at the very beginning of the program. If we need to change the threshold in the future, we will only need to change it in one place.

CHALLENGE

Write a program that does the following:

• The Finch should move forward until it is 10 cm from the wall.
• Then the Finch should back up until it is 30 cm from the wall.
• Then the Finch should move forward until it is 20 cm from the wall. 
• All of these movements should be made using a variable named distanceThreshold that is equal to 10 cm. Your program cannot contain the numbers 20 or 30. Hint: You need to use a multiplication block!

What will your program do when you change distanceThreshold to 20?

Click Here to see example code.

On the Variables menu, tap the Create List button. Name your list noteList and tap OK.

At first, the list that you create is empty, so start by adding some values. You can use the add block to add a value to the end of the list. For example, this code will add 60 to the list and then display the list on the tablet screen.

Use this script to add 5-10 different values to the list. All the values should be between 32 and 135.

Once you have values in your list, you can use them within your program.  To access a value within the list, use the item block. For example, when you tap this block, it will show the first item in the list.

Declare a variable named count. You will use this variable to access each value in your list.

What block on the Variables menu can you use to find the number of items in your list?

To access the data within a list, you can use a loop and your count variable. Consider this example code. At the beginning of the program, count is set equal to 1. Then the program uses a repeat until block to move through all the items in the list. Each time through the loop, the program displays an item of the loop and then increases the value of count. When count becomes larger than the number of items in the list, the loop ends.

CHALLENGE

Modify the loop above to make the Finch play a note for each item in the list. Now you can use a list to store a song for your Finch!

Click Here to see example code.

You can add measurements from the Finch sensors to a list to store them. For instance, this loop adds ten light measurements, one per second, to a list named lightList. Then it displays the list on the screen.

CHALLENGE

Try out the code above, and then add a loop that moves through the list and uses each of the light measurements to set the brightness of the Finch tail lights. For example, if the list contains the numbers 22, 50, etc., then the brightness of the tail lights should be 22 for one second, then 50 for one second, and so on. Note: If you need to delete all the items from your list, use the delete block and select “all.” 

Click Here to see example code.

You can find the timer block on the Tablet menu. This block measures the amount of time in seconds that has passed since the timer was reset. To use the timer block in BirdBlox, you should always first use the reset timer block.

As an example, this program measures the time that it takes the user to place the Finch in the Beak Up position. First, the program resets the timer and tells the user what to do. Then it waits until the Finch is in the Beak Up position. After the Finch is placed in that position, the program tells the user the value of the timer, which is the amount of time between the beginning of the program and the Finch being placed Beak Up. The join block is  used to combine pieces of information to display them on the screen; you can find it on the Operators menu. 

CHALLENGE

Write a program that makes the Finch move forward until it finds a line. The program should display how long it takes the robot to find the line.

Click Here to see example code.

You can also use the timer to make the robot repeat a set of actions for a certain amount of time. For example, this program will make the Finch blink its beak for 5 seconds. When the value of the timer is more than 5 seconds, the loop stops.

CHALLENGE

Modify this code to make the Finch blink its beak for 15 seconds or until it sees an obstacle, whichever happens first. Then, have the program report to the user whether or not the robot has seen an obstacle.

Click Here to see example code.

You can even combine timers with what you have learned about variables. For example, suppose you want the robot to move randomly for 15 seconds, and you want to change the random wheel speeds every second. You can do this with a variable and a timer using the code shown below. The program starts by setting the variable n equal to 1 and resetting the timer. Then a loop repeats until the value of the timer is more than 15 seconds. The action that is repeated inside the loop is to set the speeds of the wheels to random values every second. If the value of the timer is greater than n = 1, it sets the wheel speeds and increases the value of n to 2. If the value of the timer is greater than n = 2, it sets the wheel speeds and increases the value of n to 3. This process continues until the value of the timer is greater than 15 and the loop ends.

CHALLENGE

Try out the code above and make sure you understand what is happening. Then modify this code so that the Finch moves randomly until either it finds an obstacle or the timer reaches 15 seconds. If the Finch finds an obstacle within the allotted time, it should celebrate by turning its tail green and beeping happily. If it does not find an obstacle within 15 seconds, it should turn its tail red and make a low, mournful beep.

Click Here to see example code.

In BirdBlox, you can make your program more modular using two Control blocks, the broadcast and wait block and the when I receive block. These blocks work together in a program. The broadcast and wait block sends out a message. The when I receive block listens for a message and then does something when it receives that message. 

Start by tapping the when I receive block and then tap new to create a new message. Name your message “Draw Square.”

Below the when I receive block, add a loop to move the Finch in a square. Then select “Draw Square” in the broadcast and wait block. Now, when you tap on the broadcast and wait block, the Finch will move in a square.

You may notice that there is a broadcast block in BirdBlox in addition to broadcast and wait. The broadcast block sends its message and then immediately moves on to the next block. The broadcast and wait block, on the other hand, sends its message and then waits until the corresponding when I receive script ends before it moves on to the next block. This is usually what we want when working with the Finch, because the Finch will need time to finish moving before it is ready for another message.

CHALLENGE

Use the broadcast and wait block to draw multiple squares. Move or turn the Finch a little bit before drawing each new square. What interesting patterns can you create?

Click Here to see example code.

You can create additional modules by using more when I receive blocks and more messages!

CHALLENGE

Use a when I receive block to make the Finch move in a circle when it receives the message “Draw Circle.” Then draw multiple circles with the broadcast and wait block. What interesting patterns can you make with both squares and circles?

Click Here to see example code.

You can use variables to change the behavior of your modules. For example, you can modify the “Draw Square” code to use a variable to determine the side length of the square. You can set this variable before broadcasting “Draw Square” to change the size of the square. For example, the loop on the right will draw five squares with random sizes.

CHALLENGE

Use a when I receive block to make the Finch move in a polygon when it receives the message “Draw Polygon.” Use a variable to set the number of sides of the polygon. To draw a polygon, the Finch has to turn a total of 360°, so you can divide 360° by the number of sides to find the number of degrees for each turn. What interesting patterns can you make with your polygons?

Click Here to see example code.