EV3 program first aid robot

MIT App Inventor Help
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i have first aid robot and i wanna program it when it see the player in the ground go to them directly so how can i program it in mindstorm ev3

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All about what we know about eve3

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https://appinventor.mit.edu/explore/ai2/lego--ev3-pet-robot

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Building an EV3 first aid robot with App Inventor involves programming both the robot's brick and a custom Android app to serve as the remote control

. The app would allow a user to command the robot to move, and the robot would execute the commands to deliver first aid supplies.

Step 1: Design and build the EV3 robot

First, you will need to build the physical robot using the LEGO Mindstorms EV3 kit.

Materials needed

  • LEGO Mindstorms EV3 set
  • A container or platform on the robot to hold small first aid supplies like bandages, antiseptic wipes, or gauze.
  • Two motors for movement.
  • An ultrasonic sensor to detect obstacles.

Robot build considerations

  • A basic dual-wheel platform is sufficient.
  • Mount the ultrasonic sensor on the front of the robot so it can detect and avoid obstacles in its path.
  • Add a platform or a small basket to carry the first aid items.

Step 2: Create the App Inventor app

This app will serve as the remote control, sending commands via Bluetooth to the EV3 brick.

Set up the App Inventor project

  1. Go to the MIT App Inventor website and start a new project.
  2. Add a BluetoothClient component from the "Connectivity" palette.
  3. Add the Ev3Motors and Ev3UltrasonicSensor components from the "LEGO MINDSTORMS" palette.

Design the user interface (Designer view)

  1. Connection controls:
  • Add a ListPicker component. When clicked, it will display a list of paired Bluetooth devices, including your EV3.
  • Add a Button to disconnect the Bluetooth connection.
  1. Movement controls:
  • Add buttons for Forward, Backward, Left, and Right movement.
  • Alternatively, you can implement a more advanced control system where dragging a finger on the screen controls movement.
  1. Sensor feedback:
  • Add a Label to display the distance measured by the ultrasonic sensor. This helps the user avoid obstacles.
  1. Action button:
  • Add a "Deliver" button. Pressing this would trigger the robot to carry out its delivery sequence.

Program the app (Blocks view)

  1. Connect to the EV3:
  • For the ListPicker, set its BeforePicking event to get the addresses of all paired Bluetooth devices.
  • In the AfterPicking event, connect the BluetoothClient to the selected device.
  1. Control movement:
  • Use the Button.Click events to call the Ev3Motors blocks. For example, the "Forward" button would call Ev3Motors.MoveForward. You can specify motor speed and duration.
  • For the drag control, use a Canvas component and get the coordinates of the user's touch to calculate motor speeds, as demonstrated in the "One Touch Control" project.
  1. Read sensor data:
  • Use a Clock component with a Timer event to periodically call Ev3UltrasonicSensor.GetDistance and display the result in the Label.
  1. Deliver command:
  • Program the "Deliver" button to send a specific command (e.g., a number or text) to the EV3 brick using the BluetoothClient.

Step 3: Program the EV3 brick

Use the EV3 Classroom app to create a program that will run on the EV3 brick. This program will listen for Bluetooth commands from your App Inventor app.

  1. Start with the "When Program Starts" block.
  2. Set up Bluetooth: Ensure Bluetooth is enabled on the EV3 brick and it is paired with the Android device running the App Inventor app.
  3. Create a main loop: Use a Loop block set to "always" so the program continuously checks for commands.
  4. Use "Wait For Bluetooth Message": Inside the loop, use a Wait For Bluetooth Message block to receive the commands sent from your App Inventor app.
  5. Use a conditional structure:
  • Use an If/Else If block to check the incoming command.
  • If the command is "Forward," use the Move Tank block to move the motors forward.
  • If the command is "Deliver," use a sequence of movement blocks to drive to a designated drop-off location and stop.
  • For a more complex first aid task, you could program the robot to play a specific sound or display an image on the EV3 brick's screen when it receives the "Deliver" command.

Step 4: Test and refine

  1. Pair the devices: Turn on your EV3 brick, enable Bluetooth, and pair it with your Android phone.
  2. Connect via the app: Open your App Inventor app, click the ListPicker, and select your EV3 from the list.
  3. Test functionality: Try the movement controls and check that the ultrasonic sensor data is being displayed correctly.
  4. Test the delivery: Press the "Deliver" button and watch the robot execute its task. Make adjustments to the EV3 program if needed to refine the movements