68 lines
1.7 KiB
Markdown
68 lines
1.7 KiB
Markdown
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# Receive String
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Reads the next radio packet if any and returns the first string.
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## Important Security Consideration
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The functions in the ``radio`` namespace allow the BBC micro:bit to communicate with other micro:bits.
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This API does not contain any form of encryption, authentication or authorization. It's purpose is solely for use as a teaching aid to demonstrate how simple communications operates, and to provide a sandpit through which learning can take place.
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For serious applications, BLE should be considered a substantially more secure alternative.
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```sig
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radio.receiveString()
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```
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### Return value
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* the first [string](/reference/types/string) of the packet if any. ```""``` otherwise.
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### Examples
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Read the string broadcasted by other micro:bits and display it.
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```blocks
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radio.onDataReceived(() => {
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basic.showString(radio.receiveString());
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});
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```
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A simple program to send whether you are happy, or sad over ```radio```, using the A or B button to select an emotion.
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```blocks
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let data: string = "";
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input.onButtonPressed(Button.A, () => {
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radio.sendString("H");
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});
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input.onButtonPressed(Button.B, () => {
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radio.sendString("S");
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});
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radio.onDataReceived(() => {
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data = radio.receiveString();
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if ("H" == data) {
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basic.showLeds(`
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. . . . .
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. # . # .
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. . . . .
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# . . . #
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. # # # .
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`);
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} else if ("S" == data) {
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basic.showLeds(`
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. . . . .
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. # . # .
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. . . . .
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. # # # .
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# . . . #
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`);
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} else {
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basic.showString("?");
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}
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});
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```
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### See also
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[send string](/reference/input/send-string), [on data received](/reference/radio/on-data-received)
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