Introduction
What if our robot gets in trouble half way across the planet? Let's make a program so it can transmit S.O.S in Morse Code to let us know if its in trouble!
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Having red/green LEDs is a great start to communicating with our robot
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What if we want to communicate more than just red or green?
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Morse Code allows us to send any letter or number we like, just using a single light or buzzer!
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Watch the video to find out more.
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Make sure your robot is setup in the same way as the previous section.
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The red LED should be connected to P1, and the green LED should be connector to P0.
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Let's write a program that will send the letter S - this is 3 dots.
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In the picture is a program to send 1 dot with the red LED. For your pause blocks, we suggest:
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100 milliseconds for a dot
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1 second for a dash
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Extend the program in the picture to send 3 dots, which is an S.
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Can you work out how to make the S program shorter?
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We can use a do _ times loop like we used for moving the robot in a square!
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Change your program so it sends Morse Code for an S using a loop.
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You might have noticed when you were listening to the code, that between the letters we need longer gaps so you can tell when they start and finish.
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A time of 2 seconds works well.
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Put your loop that flashes an S inside the forever loop so it flashes S forever, and add a pause block so there is a gap of 2 seconds between each S.
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Let's make a program to get our robot to flash SOS using an LED, in case it has a problem.
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Your program should flash the sequence of dots and dashes required for the letters SOS - for bonus points put it in a loop to make it flash SOS forever!
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Try to shorten your program using do _ times loops.
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If you're a bit stuck, have a look in the picture to see which blocks you will need to use.
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Using lights for Morse Code is great for long distances, such as between two ships, but what if you are looking the other way when your robot is in trouble?
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Replace your LED module with the buzzer module like in the picture, so your robot buzzes SOS instead.
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If you're feeling really clever, put the LED module back into another output and add some more digital write blocks, so it flashes and buzzes the sequence for S.O.S!
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Team
