985ad3d8e3
* Add and update I2C topics * Throw in some edits for the serial buffer apis * Add an example to serial read buffer
43 lines
1.8 KiB
Markdown
43 lines
1.8 KiB
Markdown
# i2c Read Buffer
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Read data into a buffer from a device at an I2C address.
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```sig
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pins.i2cReadBuffer(0, 0, false);
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```
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A device connected to the I2C pins on the @boardname@ at the address is selected to read data from. If it has data available to transfer, the data is received and copied into a buffer for your program to use. Your program says how big (how many bytes to receive) the buffer should be. You won't get back that many bytes of data if the connected device has less to send than what you asked for.
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### ~hint
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**Simulator**
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This function needs real hardware to work with. It's not supported in the simulator.
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### ~
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## Parameters
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* **address**: the 7-bit I2C address to read the data from.
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* **size**: the [number](/types/number) of bytes to read into the buffer from the device.
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* **repeated**: if `true`, a [repeated start condition](http://www.i2c-bus.org/repeated-start-condition/) is set to help make sure the data is read from the device with out an interruption. If set to `false` (the default), the data is read without setting a start condition more than once.
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## Returns
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* a [buffer](/types/buffer) that contains the data read from the device at the I2C address. The number of bytes returned to you is less than or equal to amount you asked for in the **size** parameter.
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## Example
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Tell a device connected to the I2C pins with the address of `141` to respond to a _read status_ command. The device sends the status data on the I2C wires if receives a command byte equal to `0`. `32` bytes of status data are read into a buffer.
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```blocks
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const i2cDevice = 141;
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pins.i2cWriteNumber(i2cDevice, NumberFormat.UInt8LE, 0)
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let i2cBuffer = pins.i2cReadBuffer(i2cDevice, 32, false);
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```
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## See also
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[i2c write buffer](/reference/pins/i2c-write-buffer), [buffer](/types/buffer)
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[What's I2C?](http://www.i2c-bus.org/)
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