4.2: Keyboard Controller

Goals:

By the end of this lesson, I will be able to:

1. Identify the importance of input in programs
2. Create and run programs that include user interaction
3. Store and modify user inputs
4. Utilize user input to make decisions in a program
5. Allow user input to change program flow during flight

Steps to Success:

1. Controller
2. Takeoff
3. While Loop
4. Making Decisions
5. Challenge: Super Program

User input is also great for controlling your drone! In this activity, you will program your keyboard to act as a controller, with “W-A-S-D” and “I-J-K-L” keys as the joysticks.

First, import the “time” library. Next, show a menu of “Command options” and assign a key to each of the eight flight directions: positive and negative roll, pitch, yaw, and throttle. Make sure to include a “quit” option, which will land the drone.

Your menu should look something like this:

from codrone_edu.drone import *
import time

drone = Drone()
drone.pair()


print("Command Options: ")
print("""w: throttle up
s: throttle down
a: yaw left
d: yaw right
i: pitch forward
k: pitch backward
j: roll left
l: roll right
q: quit""")

Have your drone take off, and then set your trim if needed. This is for if your drone is drifting, and you want to fix its pitch or roll.  If you’re not having that issue, you can skip this step. 

Next, create a variable called power and set its value to 40. This way, the default power will be 40%.

Your code should look like this:

drone.takeoff()

power = 40

Set up a while loop so that while true, the program can take user input to make decisions. Next, reset the roll, pitch, yaw, and throttle to 0.

Create a variable called direction to store input(). In the parameters for input(), write “Input a command: ”. This will print the command, and when the user inputs a letter, it will be stored as an option and called later on.

Your code should look like this:

while True:

    drone.set_throttle(0)

    drone.set_roll(0)

    drone.set_yaw(0)

    drone.set_pitch(0)


    direction = input("Input a command: ")

Just like the user input menu, you need to use if, else if, and else statements to have your drone fly in different directions based on the user input. For the “w” key, use an if statement and then include a command for your drone to throttle up. In the parameters, use the power variable, which will have the drone move at 40% power.

    if direction == "w":

        drone.set_throttle(power)

For the other 7 flight commands, use else if statements. If you want the drone to go to the left, down, or backwards, put a negative sign next to the power variable in the parameters.

elif direction == "s":

    drone.set_throttle(-power)

elif direction == "a":

    drone.set_yaw(-power)

elif direction == "d":

    drone.set_yaw(power)

elif direction == "i":

    drone.set_pitch(power)

elif direction == "k":

    drone.set_pitch(-power)

elif direction == "j":

    drone.set_roll(-power)

elif direction == "l":

    drone.set_roll(power)

Write one more else if statement for the quit option. Add a wait, so the landing command isn’t skipped. Next, land the drone and break out of the loop.

    elif direction == "q":
       time.sleep(1)
       drone.land()
       break

Include an option that will let the user know they made a mistake if they input something that isn’t an option in the program. 

    else:
        print("Not a command")

Finally, include a move command for one second. This is what will actually move the drone, along with the code you wrote for each key!

  drone.move(1)

Outside the loop, include a print command so you know when you’ve exited the program.

print("Done")

Your final code should look something like this:

from codrone_edu.drone import *
import time

drone = Drone()
drone.pair()


print("Command Options: ")
print("""w: throttle up
s: throttle down
a: yaw left
d: yaw right
i: pitch forward
k: pitch backward
j: roll left
l: roll right
q: quit""")

drone.takeoff()
power = 40

while True:
    drone.set_throttle(0)
    drone.set_roll(0)
    drone.set_yaw(0)
    drone.set_pitch(0)

    direction = input("Input a command: ")

    if direction == "w":
        drone.set_throttle(power)

    elif direction == "s":
        drone.set_throttle(-power)

    elif direction == "a":
        drone.set_yaw(-power)

    elif direction == "d":
        drone.set_yaw(power)

    elif direction == "i":
        drone.set_pitch(power)

    elif direction == "k":
        drone.set_pitch(-power)

    elif direction == "j":
        drone.set_roll(-power)

    elif direction == "l":
        drone.set_roll(power)

    elif direction == "q":
        time.sleep(1)
        drone.land()
        break

    else:
        print("Not a command")

    drone.move(1)
print("Done")

drone.close()

So you have a program that uses numbers to have your CoDrone EDU do different maneuvers, and you have another program that uses letters to have your CoDrone EDU fly in different directions. What if you combined them both in the same program?

Rules:

• Must include an option to quit
• Must include a print command that lets the user know when they input an option that’s not available

In this lesson, you learned about user input! User input can be used to allow the user to decide the outcome of a program, and in this case you wrote a program to allow the user to control the CoDrone EDU using their keyboard.