71 lines
1.8 KiB
Markdown
71 lines
1.8 KiB
Markdown
# Digital Read Pin
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Read a **digital** (`0` or `1`) signal from a [pin](/device/pins) on
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the @boardname@ board.
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```sig
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pins.digitalReadPin(DigitalPin.P3)
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```
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## ~avatar
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Some pins are also used by the [LED screen](/device/screen).
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Please read the [page about pins](/device/pins) carefully.
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## ~
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## Parameters
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* ``name`` is a [string](/types/string) that stores the name of the pin (``P0``, ``P1``, or ``P2``, up through ``P20``)
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## Returns
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* a [number](/types/number) that can be `0` or `1`
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## Example: football score keeper
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This program reads pin `P0` to find when a goal is scored. When `P0`
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is `1`, the program makes the score bigger and plays a buzzer sound
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through `P2` with ``digital write pin``.
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```blocks
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let score = 0
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basic.showNumber(score)
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basic.forever(() => {
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if (pins.digitalReadPin(DigitalPin.P0) == 1) {
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score++;
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pins.digitalWritePin(DigitalPin.P2, 1)
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basic.showNumber(score)
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basic.pause(1000)
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pins.digitalWritePin(DigitalPin.P2, 0)
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}
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})
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```
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This program is a remote control for the score keeper program. If you
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connect `P1` on the remote control @boardname@ to `P0` on the score
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keeper @boardname@, you can press button `B` on the remote to buzz and
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make the score bigger on the other @boardname@.
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```blocks
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input.onButtonPressed(Button.B, () => {
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pins.digitalWritePin(DigitalPin.P1, 1);
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basic.pause(500);
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pins.digitalWritePin(DigitalPin.P1, 0);
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});
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```
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### ~hint
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Remember to connect `GND` on both @boardname@s together!
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### ~
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## See also
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[@boardname@ pins](/device/pins),
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[digital write pin](/reference/pins/digital-write-pin),
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[analog read pin](/reference/pins/analog-read-pin),
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[analog write pin](/reference/pins/analog-write-pin),
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[on pin pressed](/reference/input/on-pin-pressed),
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[pin is pressed](/reference/input/pin-is-pressed)
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