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docs/reference/radio/on-data-received.md

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+# On Data Received
+
+Registers code to run when a packet is received over ``radio``.
+
+## Important Security Consideration
+
+The functions in the ``radio`` namespace allow the BBC micro:bit to communicate with other micro:bits.
+
+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.
+
+For serious applications, BLE should be considered a substantially more secure alternative.
+
+```sig
+radio.onDataReceived(() => {})
+```
+
+### Parameters
+
+* body - is an action
+
+### Example
+
+```blocks
+basic.forever(() => {
+    radio.sendNumber(input.acceleration(Dimension.X));
+})
+radio.onDataReceived(() => {
+    led.plotBarGraph(radio.receiveNumber(), 1023);
+})
+```
+
+### See also
+
+[receive number](/microbit/radio/receive-number), [send number](/microbit/radio/send-number), [set group](/microbit/reference/radio/set-group)
+