40 lines
1.1 KiB
Markdown
40 lines
1.1 KiB
Markdown
# read Buffer
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Read available serial data into a buffer.
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```sig
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serial.readBuffer(64);
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```
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## Parameters
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* **length**: the [number](/types/number) of characters of serial data to read.
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## Returns
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* a [buffer](/types/buffer) containing input from the serial port. The length of the buffer may be smaller than the requested length.
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## ~hint
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**Pause for more data**
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If the desired number of characters are available, **readBuffer** returns a buffer with the expected size. If not, the calling fiber (the part of your program calling the **readBuffer** function) sleeps until the desired number of characters are finally read into the buffer.
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The need to pause for more data is set by the @boardname@ **[serial mode](https://lancaster-university.github.io/microbit-docs/ubit/serial/#serial-modes)**.
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## ~
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## Example
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Read character data from the serial port one row at a time. Write the rows to an LED display connected to the I2C pins.
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```typescript
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let rowData: Buffer = null;
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for (let i = 0; i < 24; i++) {
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rowData = serial.readBuffer(80);
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pins.i2cWriteBuffer(65, rowData, false);
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}
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```
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## See Also
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[write buffer](/reference/serial/write-buffer)
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