Instrument-control Toolkit - spi_write
- Loadable Function: 
n =spi_write(spi, data) -  
Write data to a spi slave device.
Inputs
spi - instance of octave_spi class.
data - data, of type uint8, to be written to the slave device.Outputs
Upon successful completion, spi_write() shall return the number of bytes written as the result n.