pxt-calliope/docs/projects/mini-chat.md

Mini Chat

Introduction @unplugged

Use the radio to send and receive messages with other @boardname@.

Sending a message @fullscreen

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

input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
    radio.sendString("Yo");
});

Receiving a message @fullscreen

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

radio.onReceivedString(function (receivedString) {
})

Displaying text @fullscreen

Add a ||basic:show string|| to display the string on the screen. Pull the ||variables:receivedString|| out of ||radio:on received string|| and put it into ||basic:show string||.

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

Testing in the simulator @fullscreen

Press button A on the simulator, you will notice that a second @boardname@ 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 @boardname@.

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

Try it for real @fullscreen

If you two @boardname@s, download the program to each one. Press button A on one and see if the other gets a message.

Groups @fullscreen

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

radio.setGroup(123)

radio