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Write binary data to SPI instrument


write(OBJ, A)


write(OBJ, A) writes the data, A, to the SPI instrument connected to interface object, OBJ. OBJ must be a 1-by-1 SPI interface object. By default the 'uint8' precision is used.

The interface object must be connected to the device with the connect function before any data can be read from or written to the device, otherwise an error is returned. A connected interface object has a ConnectionStatus property value of connected.

The SPI protocol operates in full duplex mode, input and output data transfers happen simultaneously. For every byte written to the device, a byte is read back from the device. This function will automatically flush the incoming data.


To get a list of options you can use on a function, press the Tab key after entering a function on the MATLAB® command line. The list expands, and you can scroll to choose a property or value. For information about using this advanced tab completion feature, see Using Tab Completion for Functions.


This example shows how to create a SPI object s, and read and write data.

Construct a spi object called s using Vendor 'aardvark', with BoardIndex of 0, and Port of 0.

s = spi('aardvark', 0, 0);

Connect to the chip.


Write to the chip.

dataToWrite = [2 0 0 255]
write(s, dataToWrite);

Disconnect the SPI device and clean up by clearing the object.


Version History

Introduced in R2013b