Micro Chat

Introduction

Use the radio to send and receive messages with other micro:bit.

Sending a message

Use ||input:on button pressed|| to send a text message over radio with ||radio:send string||. Every micro:bit nearby will receive this message.

input.onButtonPressed(Button.A, () => {
    radio.sendString("Yo");
});

Receiving a message

Add a ||radio:on received string|| block to run when a message is received.

radio.onReceivedString(function (receivedString) {
})

Displaying text

Add a ||basic:show string|| to display the string on the screen. You will find the receivedString variable under Variables in the toolbox.

radio.onReceivedString(function (receivedString) {
    basic.showString(receivedString);
})

Testing in the simulator

Press button A on the simulator, you will notice that a second micro:bit appears (if your screen is too small, the simulator might decide not to show it). Try pressing A again and notice that the “Yo” message gets displayed on the other micro:bit.

input.onButtonPressed(Button.A, () => {
    radio.sendString("Yo");
});
radio.onReceivedString(function (receivedString) {
    basic.showString(receivedString);
})

Try it for real

If you two micro:bits, download the program to each one. Press button A on one and see if the other gets a message.

Groups

Use the ||radio:set group|| block to assign a group number to your program. You will only receive messages from micro:bits within the same group. Use this to avoid receiving messages from every micro:bit that is transmitting.

radio.setGroup(123)

radio