RTLSDR

A wrapper for the librtlsdr C libraries. Currently, this only works on Linux (I think). You need to download the librtlsdr libraries.

This code is heavily based off the pyrtlsdr libary by github user roger-.

librtlsdr C libraries

Julia needs to find librtlsdr.so somewhere on your system. To see if Julia can find it, you can use find_library:

using Libdl
find_library("librtlsdr")   # returns empty string if library not found

You can also type the following into an Ubuntu shell to help find it:

ldconfig -p | grep librtlsdr

Quick Example

using RTLSDR

r = RtlSdr()

set_rate(r, 2.0e6)
set_freq(r, 88.5e6)		# if we wanted the center freq on NPR

samples = read_samples(r, 1024)

# plot power spectral density
using PyPlot
psd(samples)

Function list

r = RtlSdr()            # creates RtlSdr object with dongle pointer

set_rate(r, rate_Hz)      # rtlsdr_set_sample_rate
get_rate(r)

set_freq(r, freq_Hz)    # rtlsdr_set_center_freq
get_freq(r)

set_agc_mode(r, mode)               # rtlsdr_set_agc_mode
set_tuner_gain_mode(r, manual)      # rtlsdr_set_tuner_gain_mode

close(r)    # rtlsdr_close. cannot read from r once this is called

# rtlsdr_read_sync
# returns vector of length num_bytes with Uint8 (bytes)
# num_bytes must be multiple of 512
read_bytes(r, num_bytes)

# converts vector of Uint8 into a vector (half as long) of complex iq samples
packed_bytes_to_iq(bytes)

# equivalent to read_bytes + packed_bytes_to_iq
# returns a vector of length num_samples with complex samples
# num_samples must be multiple of 256
read_samples(r, num_samples)