spi-config - Man Page

set or query SPI configuration.

Synopsis

spi-config options...

Description

Set or query the configuration of a SPI port.

-d,  --device=DEVICE

use the given Linux spidev character device.

-q,  --query

print the current configuration.

-m,  --mode=[0-3]

set the spi mode (see Spi Modes below).

-l,  --lsb={0,1}

set LSB first (1) or MSB first (0).

-b,  --bits=[7...]

set the number of bits per word.

-s,  --speed=FREQUENCY

set clock frequency (in Hz).

-r,  --spirdy={0,1}

set the SPI READY mode flag.

-s, --wait

block, keeping the file descriptor open. See Wait Option below.

-h,  --help

display the help screen and exit.

-v,  --version

display the version number and exit.

Spi Modes

mode 0

low iddle level, sample on leading edge.

mode 1

low iddle level, sample on trailing edge.

mode 2

high iddle level, sample on leading edge.

mode 3

high iddle level, sample on trailing edge.

Wait Option

On some platforms, the speed is reset to a default value when the file descriptor is closed. To avoid this, one can use the -w option that keeps the file descriptor open. See also last example below.

Examples

Get help:

$ spi-config -h

Query current configuration:

$ spi-config --device=/dev/spidev0.0 -q

Change clock frequency to 1 MHz:

$ spi-config --device=/dev/spidev0.0 --speed=1000000

Set a configuration and keep the device open:

$ spi-config --wait --speed=1000000 & PID=$!

Close device previously open:

$ kill $PID

Author

Written by Christophe BLAESS <http://www.blaess.fr/christophe>.

Reporting Bugs

Github home page: <https://github.com/cpb-/spi-tools.git>

Info

August 2014 SPI-tools