75 lines
1.9 KiB
Markdown
75 lines
1.9 KiB
Markdown
# on Received Number
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Run part of a program when the @boardname@ receives a
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[number](/types/number) over ``radio``.
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```sig
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radio.onReceivedNumber(function (receivedNumber) {})
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```
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## Parameters
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* **receivedNumber**: The [number](/types/number) that was sent in this packet or `0` if this packet did not contain a number. See [send number](/reference/radio/send-number) and [send value](/reference/radio/send-value)
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## ~ hint
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Watch this video to see how the radio hardware works on the @boardname@:
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https://www.youtube.com/watch?v=Re3H2ISfQE8
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## ~
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## Examples
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### Tell me how fast
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This program keeps sending numbers that say how fast the @boardname@ is
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slowing down or speeding up. It also receives numbers for the same
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thing from nearby @boardname@s. It shows these numbers as a
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[bar graph](/reference/led/plot-bar-graph).
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```blocks
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basic.forever(() => {
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radio.sendNumber(input.acceleration(Dimension.X));
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})
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radio.onReceivedNumber(function (receivedNumber) {
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led.plotBarGraph(receivedNumber, 1023);
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})
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```
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### What's the distance?
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This program uses the signal strength from received packets to graph the
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approximate distance between two @boardname@s.
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```blocks
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basic.forever(() => {
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radio.sendNumber(0)
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})
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radio.onReceivedNumber(function (receivedNumber) {
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led.plotBarGraph(
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Math.abs(radio.receivedPacket(RadioPacketProperty.SignalStrength) + 42),
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128 - 42
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)
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})
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```
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## Troubleshooting
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The ``||radio:onReceivedNumber||`` event can only be created once, due to the hardware restrictions.
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The radio set group might need to be set, synchronized, before the radio events will function.
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## See also
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[on received string](/reference/radio/on-received-string),
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[received packet](/reference/radio/received-packet),
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[send number](/reference/radio/send-number),
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[send string](/reference/radio/send-string),
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[send value](/reference/radio/send-value),
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[set group](/reference/radio/set-group)
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```package
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radio
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```
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