iio_readdev(1) LibIIO Utilities iio_readdev(1)

iio_readdev - read buffers from an IIO device

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

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

Tells iio_readdev to display some help, and then quit.
Prints the version information for this particular copy of iio_readdev and the version of the libiio library it is using. This is useful for knowing if the version of the library and iio_readdev on your system are up to date. This is also useful when reporting bugs.
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 available.
Use the specified trigger, if needed on the specified channel
Size of the capture buffer. Default is 256.
Number of samples (not bytes) to capture, 0 = infinite. Default is 0.
Buffer timeout in milliseconds. 0 = no timeout. Default is 0.
The Uniform Resource Identifier (uri) for connecting to devices, can be one of:
network address, either numeric (192.168.0.1) or network hostname
blank, if compiled with zeroconf support, will find an IIO device on network
normally returned from iio_readdev -S
which are controlled, and need to match the iiod (or tinyiiod) on the other end of the serial port.
[port]
is something like '/dev/ttyUSB0' on Linux, and 'COM4' on Windows.
[baud]
is is normally one of 110, 300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 38400, 57600, 115200 [default], 128000 or 256000, but can vary system to system.
[settings]
would normally be configured as '8n1' this is controlled by:
(5, 6, 7, 8 [default], or 9)
('n' none [default], 'o' odd, 'e' even, 'm' mark, or 's' space)
(1 [default, or 2)
('0' none [default], 'x' Xon Xoff, 'r' RTSCTS, or 'd' DTRDSR)
with no address part.

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

You use iio_readdev in the same way you use many of the other libiio utilities. You should specify a IIO device, and the specific channel to read. Since this is a read, channels must be input. If no channel is provided, iio_readdev will read from all input channels. If no device is provided, iio_readdev will print a few examples:

iio_readdev -a
Using auto-detected IIO context at URI "usb:3.10.5"
Example : iio_readdev -u usb:3.10.5 -b 256 -s 1024 cf-ad9361-lpc voltage0
Example : iio_readdev -u usb:3.10.5 -b 256 -s 1024 cf-ad9361-lpc voltage1
Example : iio_readdev -u usb:3.10.5 -b 256 -s 1024 cf-ad9361-lpc voltage2
Example : iio_readdev -u usb:3.10.5 -b 256 -s 1024 cf-ad9361-lpc voltage3
Example : iio_readdev -u usb:3.10.5 -b 256 -s 1024 cf-ad9361-lpc

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;"

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/

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

24 September 2023 libiio-0.25