18. Introduction to Bluetooth
Bluetooth uses radio frequencies to communicate between devices
The EV3 uses Bluetooth to download programs wirelessly
The EV3 also uses Bluetooth to connect to another EV3:
– Have them perform similar actions
– Synchronize their actions
Tips for Success
Give each brick an unique name (Sender and Receiver for this lesson)
Use an USB cable for downloading code to the bricks (rather than Bluetooth). You cannot connect between EV3s and a PC at the same time
Turn on the receiver robot first then the sender in the challenges in this lesson. This is because the challenge solution only sends the message once in Challenge 1.
18.1. Activating Bluetooth on the EV3
– On the EV3 menu, go to the symbol that looks like a wrench
– Go down to the word “Bluetooth” and activate it
To connect to another brick go back into the Bluetooth menu
– Go to “Connections”
– Select “Search” and find the other brick’s name
You can also manage your connections with the Bluetooth Connection Block.
18.2. Messaging Block
– The messaging block can be found in the Blue Pallet.
– You will also use the Wait For block in Messaging Mode
Challenge 1:
– Send a “Hello World” message from one brick to another
– The second brick should receive and display the message on its screen for 5 seconds
Hint: You will need to pair the two robots ahead of time. Name the robots by your team name (eg Hungary1) to ensure the uniqueness of the names. For this challenge, you will use the Messaging block -> Send -> Text. You will use the Wait For block in the Messaging Mode -> Change -> Text
Challenge 2: Synchronized Swimmers
– Move the first robot by hand and send the motors’ power to the other robot
– Have the second brick receive the data and copy the movement