RTL-SDR IndieGoGo sprint
Work on rtl_fm
Rtl_fm already supports a lot of features,
but there is still lots to do.
No one in my area uses trunking.
I may need interested people to provide recordings.
Multiple dongles (rtl_fm)
Demodulate any number of channels, anywhere in the spectrum.
Basic antenna diversity could come out of this too.
Demodulate any number of channels that are within 2.4MHz.
Demod two channels simultaneously.
One goes to the left stereo channel, the other to the right.
Also known as named pipes.
Rtl_fm uses a fixed 90 degree translation.
Multiple channels will need different amounts of translation.
Lots of room for improvement here, probably the #1 area of complaint.
Only one type of squelch is supported,
other types exist and should be options.
Limit open squelch
A time maximum that a carrier can hold the squelch open.
This might require using a channel configuration file.
Generate null audio on squelch
Normally when squelch kicks in, the output is stopped.
This causes issues with streaming programs.
The present squelch option is dependent on every other option.
Make the squelch math unit-less and more consistent.
Allow rtl_fm to support all rtl_tcp features.
Clean up and merge rtl_udp
Modular engine and modular config
Allow DSP to be chained together in an arbitrary fashion.
Oversample mode requires extra lowpasing in order to be effective.
Port to non-rtlsdr hardware
First, I would need access to the hardware in question.
Second, this could easily get very complicated very fast.
Signals with a well-defined carrier can be automatically tuned.
This could correct for thermal drift, doppler shift, or small typos.
Load and process pre-recorded raw iq streams.
WBFM support is currently the lowest quality to confirm a dongle is working.
The present resampler is a pretty terrible boxcar filter.
Replace it with (at least) a CIC filter.
WBFM stereo mode
Various levels of freq, timestamp, power, squelch.
Create files such as 'freq_date_time.wav/raw'
(Only works with squelch.)
Track more information about channels
Information like last time seen, power level, per-channel squelch.
Fix '-F 9' filter
Produces a ticking sound in the audio at the buffer boundary.
Optional wav header
Generate a header to make post-processing easier.
Better AM demod
Drastically reduce the amount of memory transfers performed.
Perform everything in-place
Most of the code functions in-place, but none of the demodulators do.
Work on misc utilities
There are some gaps in the SDR tool chain.
Generic fsk/ask/ook demodulator
Audio stream in, raw bits out.
Work on librtlsdr
This is probably my weakest area and the most difficult section of code.
But I've written a bunch of usablity improvements and there are plenty more to do.
I can also do the boiler plate coding to transform your proof-of-concept patch into something likely to be merged.
Port reset/re-init on disconnect
Sometimes the USB will flake out.
Wouldn't it be nice if the library could power-cycle the USB port, restore the dongle's state and continue where it left off?
(Detected and handled automatically of course.)
'auto' as a valid gain value
There is no standard way to select automatic gain from the command line.
By using '-g auto', automatic gain can be forced.
Update safe max to 2.4MS/s
When most of rtl_foo was written, 2.8MS/s was the safe upper limit.
Now it has been found to actually be 2.4MS/s and everything requires small tweaks.
Quiet mode for tuning errors
The new range tests generate hundreds of harmless errors.
Report true frequency when dithering
The PLL has a resolution of 439.45Hz when not dithering.
Warn when sampling above safe limit
During verbose operation, the library should produce a warning when sampling is dangerously high.
I enjoy writing groff by hand and think everything should have a manpage.
This might be split into two subgoals, for the rtl_foo commands and rtl-sdr.h
merbanan's r820t range test
Rebase old patches to HEAD
Make things easy for the Osmocom guys to merge
By default, the r820t will dither the PLL for more exact tuning.
Disabling this is required for phase-aligning multiple synchronized dongles.
Add units to rtl_sdr -n
This option is missing K/M/G support.
Tejeez's retuning patches
By reducing the amount of I2C overhead, tuning can happen 2.5x faster.
This will mostly benefit rtl_power and rtl_fm.
i2c repeater toggles
Keep the i2x channel open while in use, instead of toggling.
Send all changed registers in a single burst
Only update registers when they are changed
Tejeez's filter patches
Tejeez has done a lot of great work with finding optimal filter registers for various bandwidths.
These might be chosen automatically or given a new API call.
Work on rtl_sdl
This was originally a little demo thrown together in three days.
It has the potential to be the fastest, lightest and easiest to build waterfall ever.
screenshot 1 screenshot 2
One of the simplest ways of ID-ing a modulation.
Plots the IQ pairs on an XY plane.
Turn rtl-sdl into a real waterfall.
Mouse/keyboard controls to select a channel's freq and width.
SDL provides a nice cross-platorm audio library.
Basically would merge rtl_fm into the waterfall.
Turn rtl-sdl into a real waterfall.
Mouse/keyboard controls to select a channel's freq and width.
Remote control UI
Yes, the useless one.
(Feature may be linux-only, we'll see how WinLIRC goes.)
Calculates the self-symmetry of a signal.
Very handy for deciding if a signal carries useful information.
Save your channels and quickly restore them.
Originally it was designed for a touch screen.
There are some non-sensical keybinds that map to the touch screen's hardware buttons.
There is no way to change the on-screen bandwidth.
Should also report the displayed bandwidth as well.
Window size detection
The screen size is fixed to the original demo hardware.
It does not yet detect full-screen or window resizing.
Work on rtl_power
A waterfall power logger, without the burden of a GUI.
Heatmap was originally supposed to be a proof of concept.
It needs some work to become a serious plotting tool.
Convert rtl_power output directly to a heatmap
without saving the CSV to disk.
Automatic image chunking
Every Y pixels, automatically save the image and start fresh.
Provide db limits on CLI
Normally the min/max range requires a preliminary pass
Let the user provide the range and skip this pass.
Given a frequency or time range, draw only that section of the data.
Should be capable of relative time, such as "last hour".
DLBB's satellite features
Places marks around where and when a satellite should be detectable.
pksato's time stamps
Provide an interval and get time-ticks along the Y axis.
Up/down converter shift
A command line option to offset the frequencies.
Heatmap 24h rollover
Runs that cross over midnight report an incorrect duration.
Automatically scale the density/resolution of frequency labels
so there are always some visible and no overlap.
Produce files that can be read directly by gnuplot.
Multiple dongles (rtl_power)
There are three cases to consider here:
1. Dongles == bands. Monitor all bands without hopping.
2. Dongles < bands. Hop in rotation.
3. Dongles > bands. Continuously monitor with most, hop with the remainder.
(It might be worthwhile to specify which dongles do which bands, for better antenna use.)
Right now rtl_power drops data while the FFT is being processed.
HDF5 is a popular binary format for scientific data.
Most likely this would be a stand-alone filter and not integrated into rtl_power.c
Radio astronomy features
A lot of astronomy is measuring signal power, but rtl_power is not really suited for RA yet.
Linear output option
Rtl_power only support a logarithmic db output scale.
An option for a linear scale would help with quantitative measurements.
Wouldn't it be nice if a program could read the CSV directly,
without a length and memory-intensive conversion process?
Most importantly, it would give the exact time and frequency of a signal under your cursor.
Rtl_power activity summary
Convert an rtl_power CSV file into a time/freq/duration activity log.
Possible sub-task for making it operate real-time?
Flag for bandwidth control
There are several sample rates to meet a given FFT.
Default is fastest, make option for slowest.
An external script that converts the csv to active timestamped frequencies.
Field for max sample rate
A higher sample rate means less hops, a lower sample rate might have less imaging.
Measure multiple frequency ranges
Multiple -f options should allow scanning of non-contiguous bands.
Fixed bins (variable crop)
Rtl_power should give you the exact size of bin you ask for,
instead of fudging it to make the math easier.
Guide with examples
A big long document with lots of pictures and examples of the most common use cases.
Work on rtl_adsb
A very small ADS-B demodulator.
Normally the output is piped to a plotting program.
Doubling the sample rate would improve the SNR by half a bit and pick up weaker, more distant signals.
It will also increase the CPU use 3x or 4x so this will be optional.
Right now it can only produce the raw ADS-B hex.
Instead, fully decode the message.
At present it does no CRC checks.
If there are very few errors, it is possible to fix them and recover the message.
Network output for adsb
Provide an option to send output directly to an ip/port.
Work on rtl_tcp
Rtl_tcp lets remote control dongles and stream across networks.
GZ compress stream
Typically compresses by 7x.
Provide a mechanism for 3rd party programs to follow dongle state.
For example, to automatically switch antennas based on tuning range.
Automatic Windows build
I occasionally make windows DLLs for those without compilers.
This could be done continuously and automatically for each commit.
(They'll be built with Mingw32. Maybe 64 bit as well.)