iio_readdev(1)

NAME
iio_readdev - read buffers from an IIO device

SYNOPSIS
iio_readdev [ options ] [-n <hostname>] [-t <trigger>] [-T <timeout-ms>] [-b <buffer-size>] [-s <samples>] <iio_device> [<channel> ...]

DESCRIPTION
iio_reg is a utility for reading buffers from connected IIO devices, and sending resutls to standard out.

OPTIONS

-h, --help
    Tells iio_readdev to display some help, and then quit. -n, --network Use the network backend with the provided hostname

-u, --uri
    The Uniform Resource Identifier (uri) for connecting to devices, can be one of:

    ip:[address]
        network address, either numeric (192.168.0.1) or network hostname

    ip: blank, if compiled with zeroconf support, will find an IIO device on network

    usb:[device:port:instance]
        normally returned from iio_info -s

    serial:[port]

    local
        with no address part

-t --trigger
    Use the specified trigger, if needed on the specified channel

-b --buffer-size
    Size of the capture buffer. Default is 256.

-s --samples
    Number of samples (not bytes) to capture, 0 = infinite. Default is 0.

-T --timeout
    Buffer timeout in milliseconds. 0 = no timeout. Default is 0.

-a, --auto
    Scan for available contexts and if only one is available use it.

-S, --scan
    Scan for available IIO contexts, optional arg of specific backend(s) 'ip', 'usb' or 'ip,usb'. Specific options for USB include Vendor ID, Product ID to limit scanning to specific devices 'usb=0456:b673'. vid,pid are hexadecimal numbers (no prefix needed), "*" (match any for pid only) If no argument is given, it checks all that are availble.

RETURN VALUE
If the specified device is not found, a non-zero exit code is returned.

USAGE

You use iio_readdev in the same way you use many of the other libiio utilities. You must specify a IIO device, and the specific channel to read. Since this is a read, channels must be input. It is easy to use iio_attr to find out what the channels are called.

This identifies the device, and channel that can be used.
    iio_attr -a -i -c .
    Using auto-detected IIO context at URI "usb:3.10.5"
    dev 'cf-ad9361-lpc', channel 'voltage0' (input, index: 0, format: le:S12/16>>0)
    dev 'cf-ad9361-lpc', channel 'voltage1' (input, index: 1, format: le:S12/16>>0)

This captures 1024 samples of I and Q data from the USB attached AD9361, and stores it (as raw binary) into the file samples.dat
    iio_readdev -a -s 1024 cf-ad9361-lpc voltage0 voltage1 > samples.dat

And plots the data with gnuplot.
    gnuplot -e "set term png; set output 'sample.png'; plot 'sample.dat' binary format='%short%short' using 1 with lines, 'sample.dat' binary format='%short%short' using 2 with lines;"

SEE ALSO
iio_attr(1), iio_info(1), iio_readdev(1), iio_reg(1), iio_writedev(1), libiio(3)

libiio home page: https://wiki.analog.com/resources/tools-software/linux-software/libiio

libiio code: https://github.com/analogdevicesinc/libiio

Doxygen for libiio https://analogdevicesinc.github.io/libiio/

BUGS
All bugs are tracked at: https://github.com/analogdevicesinc/libiio/issues