Setting up the sdr touch program. SDR Touch -Live offline radio. Software and API for working with RTL2832

I am sure that for many of you, like for me quite recently, what was happening on the radio was real magic. We turn on the TV or radio, pick up the phone cell phone, we determine our position on the map using GPS or GLONASS satellites - and all this works automatically. Thanks to RTL-SDR we now have affordable way look inside all this magic.

As already mentioned, RTL-SDR is a whole family of cheap TV tuners that can perform the function of an SDR receiver. These toys have different names and brands, but they have one thing in common - they are all built on the RTL2832 chipset. This is a chip containing two 8-bit ADCs with a sampling rate of up to 3.2 MHz (however, above 2.8 MHz there may be data loss), and a USB interface for communication with a computer. This chip receives I and Q streams at its input, which must be received by another chip.

R820T and E4000 are the two most convenient chips for SDR, implementing the RF part of SDR: an antenna amplifier, a tunable filter and a quadrature demodulator with a frequency synthesizer. The figure shows a block diagram of the E4000.

The difference between the two is that the E4000 operates in the ~52-2200 MHz range and has slightly greater sensitivity below 160 MHz. Due to the fact that the E4000 manufacturer went bankrupt and the chip was discontinued, the remaining tuners are becoming increasingly difficult to buy, and their prices are rising.

The R820T operates in the range of 24–1766 MHz, but the tuning range of the internal filters makes it very difficult for the R820T to operate above 1200 MHz (making it impossible, for example, to receive GPS). At the moment, tuners based on this chip are easy to buy, and they cost about 10–11 dollars.

Tuners based on FC0012/FC0013/FC2580 chips are also sold - they have very serious limitations on operating frequencies, and it is better not to buy them. You can find out which chip the tuner is made from in the product description or by asking the seller. If there is no information on the chips used, it is better to buy elsewhere.

Purchase

You can't find them in retail stores, so aliexpress.com will help us. We write R820T or E4000 in the search, sort by the number of orders, carefully read the description (it should be clearly written there that the tuner uses RTL2832 + E4000 or RTL2832 + R820T chips), and you can order. They are usually sent by Russian Post within 3-6 weeks.

The tuner will also come with a tiny antenna - it is, of course, better to replace it. Good results can be obtained using ordinary room TV antenna MV-UHF "horns". In the product description you also need to pay attention to the antenna connector - and either look for a tuner with a regular TV connector, or take out your soldering iron and make an adapter / resolder the connector. It is very easy to kill the device when soldering static electricity, so get grounded.

Many tuners do not have protective diodes near the antenna connector (in in this case U7) - you can either solder them yourself (one to ground, one from ground - I, for example, soldered 1N4148), or leave them as is, and do not touch the antenna with bare hands and protect it in every possible way from static electricity.

Software and API for working with RTL2832

rtl_sdr

Rtl_sdr is a driver that provides “inappropriate” use of data from TV tuners based on rtl2832. On Windows, you will have to change the default tuner driver to WinUSB using the Zadig program.

Rtlsdr.dll is required by all SDR programs, and often this DLL is already included in software that uses RTL2832.

Rtl_sdr can also be used through the console utility to test the tuner or merge a piece of air into a file:

Rtl_sdr -f 1575520000 -g 34 -s 2048000 out.dat

During further processing, you need to remember that in the file the bytes of I- and Q-streams appear alternately.

SDRSharp

What to listen to on the radio?

Radio communications in unlicensed bands

Civilian radios, which do not require registration in Russia, operate on frequencies of 433 and 446 MHz. However, in Moscow it is difficult to hear Russian speech there. They can be heard immediately and without problems in SDRSharp, NFM modulation.

Since there are many channels, the SDRSharp AutoTuner Plugin is very useful - it automatically turns on the frequency on which the transmission is carried out, and thus you can listen to all radio channels at once.

To listen to walkie-talkies at a frequency of 27 MHz, you need a tuner with an R820T chip or an external converter in the case of the E4000 (for example, the previously described Ham It Up v1.2). The optimal antenna for 27 MHz already requires a more serious one, ~2.59 or ~1.23 m long.

Police radio communications

Police in Moscow and many other regions of Russia have switched to using digital radios operating in the APCO-25 (P25) standard. In P25, data is transmitted digitally with compression and error correction codes - this allows you to increase the stable communication range and cram more channels into the same radio frequency band. There is also the option of encrypting conversations, but regular police work without encryption.

A DSD decoder can be used to receive P25 radios. DSD expects audio data as input. You can redirect audio from SDRSharp to DSD with using Virtual Audio Cable. DSD is very critical of the SDRSharp settings - I recommend setting AF Gain to about 20–40%, and perhaps disabling the Filter Audio checkbox. If everything goes according to plan, decoded packets will run in the DSD window, and conversations will be heard in the headphones. This circuit also works with the mentioned AutoTuner plugin in SDRSharp.

I suggest that readers find the frequencies on their own, since this information is not open.

Radio communications between aircraft and dispatchers

For historical reasons, amplitude modulation is used for aviation radio communications. Generally, transmissions from aircraft are easier to hear than from controllers or weather reporters on the ground. Frequency range - 117–130 MHz.

Reception of signals from automatic transmitters of ADS-B aircraft

ADS-B is used to provide both the controller and the pilot with visibility into the air situation. Each aircraft regularly transmits flight parameters on a frequency of 1090 MHz: flight name, altitude, speed, azimuth, current coordinates (not always transmitted).

We can also accept this data in order to personally observe the flights. Two popular ADS-B decoders for RTL2832 are ADSB# and RTL1090. I used ADSB#. Before starting, it is advisable to tune to 1090 MHz in SDRSharp, see if there is a signal and what the frequency error is due to the inaccuracy of the crystal oscillator. This error must be compensated in the Front-end settings: Frequency correction (ppm). It must be remembered that the magnitude of this error may change with the temperature of the receiver. The found correction must be indicated in the ADSB### window (after closing SDRSharp).

The optimal monopole antenna for 1090 MHz is only 6.9 cm long. Since the signal is very weak, it is very desirable to have a dipole antenna installed vertically with the same length of elements.

ADSB# decodes packets and waits for network connections from the client displaying the air situation. We will use adsbSCOPE as such a client.

After launching adsbSCOPE, you need to open the menu item Other -> Network -> Network setup, click on the adsb# button below, make sure that the server address is 127.0.0.1. Then you need to find your location on the map and execute the command Navigation -> Set Receiver Location. Then start connecting to ADSB#: Other -> Network -> RAW-data client active.

If everything is done correctly, then within a few minutes you will be able to see information about the planes (if, of course, they fly near you). In my case, with a monopole antenna, it was possible to receive signals from aircraft at a distance of approximately 25 km. The result can be improved by taking a higher quality antenna (dipole or more complex), adding an additional amplifier at the input (preferably GaAs), using a tuner based on the R820T (at this frequency it has higher sensitivity compared to the E4000).

Reception of long and short wave analogue and digital radio stations

Before the advent of the Internet, HF radio stations were one of the ways to find out news from the other side of the globe - short waves, reflected from the ionosphere, can be received far beyond the horizon. A large number of HF radio stations still exist today; they can be searched in the range of ~8–15 MHz. At night in Moscow I was able to hear radio stations from France, Italy, Germany, Bulgaria, Great Britain and China.

Further development - digital DRM radio stations: compressed audio with error correction is transmitted on short waves + additional information. You can listen to them using a decoder. The frequency range for search is from 0 to 15 MHz. It must be remembered that for such low frequencies a larger antenna may be needed.

In addition, you can hear radio amateur transmissions at frequencies of 1810–2000 kHz, 3500–3800 kHz, 7000–7200 kHz, 144–146 MHz, 430–440 MHz and others.

Doomsday Radio - UVB-76

UVB-76 is located in western Russia, has been transmitting on the 4.625 MHz frequency since the early 1980s, and has an unclear military purpose. From time to time, coded voice messages are transmitted over the air. I managed to receive it using an RTL2832 with a converter and a 25-meter antenna lowered from the balcony.

GPS

One of the most unusual opportunities- reception navigation signals from GPS satellites to the TV tuner. To do this, you will need an active GPS antenna (with an amplifier). You need to connect the antenna to the tuner through a capacitor, and before the capacitor (on the side of the active antenna) - a 3 V battery to power the amplifier in the antenna.

Next, you can either process the leaked ether dump with a matlab script - this may be interesting in order to study the principles GPS operation, - or use GNSS-SDR, which implements real-time decoding of GPS signals.

It would be difficult to receive a signal from GLONASS satellites in a similar way - different satellites there transmit to different frequencies, and all frequencies do not fit into the RTL2832 band.

Other applications and limits

The RTL2832 can be used for debugging radio transmitters, eavesdropping on baby monitors and analogue radiotelephones, analyzing communication protocols in radio-controlled toys, radio bells, car remote controls, weather stations, systems for remote collection of information from sensors, and electric meters. With the converter you can read the code from the simplest 125 kHz RFID tags. Signals can be recorded for days, analyzed and then re-broadcast on transmission equipment. If necessary, the tuner can be connected to an Android device, Raspberry Pi or other compact computer to organize autonomous data collection from the radio air.

You can take photographs from weather satellites and listen to broadcasts from the ISS - but this will require special antennas and amplifiers. Photos are decoded by the WXtoImg program.

It is possible to capture encrypted data transmitted by GSM phones (airprobe project) if frequency-hopping is disabled on the network.

The possibilities of SDR based on RTL2832 are still not limitless: it does not reach Wi-Fi and Bluetooth in frequency, and even if you make a converter, due to the fact that the captured frequency band cannot be wider than ~2.8 MHz, it is impossible will accept even one Wi-Fi channel. Bluetooth changes 1600 times per second operating frequency in the range of 2400–2483 MHz, and it will be impossible to keep up with it. For the same reason, full reception is impossible analog television(there you need a received band of 8 MHz; with 2.8 MHz you can only get a black and white picture without sound). For such applications, more serious SDR receivers are needed: HackRF, bladeRF, USRP1 and others.

Nevertheless, everyone now has the opportunity to explore both analog and digital radio broadcasts, touch satellites and airplanes!

Now begins the painstaking work of installing drivers and control software. As they say, don’t “run ahead of the locomotive,” but do it exactly according to the instructions. Step by step.

1. If you purchased an SDR receiver like from us (http://ali.pub/1p0ml2), then it will come with a small disk with drivers. If there is no disk, or you don’t have a CD-Rom, it doesn’t matter, these are the drivers https://yadi.sk/d/bjfPakpC3RCZx2

2. Connect the SDR receiver to USB port computer. If the computer prompts you to start searching for drivers, refuse.

3. Install the receiver driver by running the Setup.exe file from the disk or by downloading them from the link above. Follow the instructions, there is nothing complicated, everything is standard. Sometimes a warning window may appear, saying that Windows cannot detect digital signature drivers, it's not scary, click - Install anyway.

4. Now you need to install the second driver, it is called Zadig. Download from here http://zadig.akeo.ie Direct link to the driver http://zadig.akeo.ie/downloads/zadig-2.3.exe Direct link from Yandex disk, if the previous ones for some reason do not work https http://yadi.sk/d/2yDgeQeW3RCas9

5. The SDR receiver must be connected to the computer all this time. Run the downloaded file zadig-2.3.exe In the driver menu at the top, click Options and check the List All Devices box. This is so that the driver can see your SDR receiver.

6. After this, a list of your all will appear in the program window USB devices, including an SDR receiver. It will be displayed as Bulk-In, Interface (Interface 0), select it.

7. After that, click the big Replace Driver button

8. The Zadig driver will begin installation, after which a window will appear indicating that the driver is installed. Click "Close" and close the Zadig program. At this point, the most difficult stage is completed.

Now you need to download, install and configure the program with which you will control your SDR receiver.
There are many programs, they all differ in functions, convenience, availability of additional plugins, etc. It is impossible to say for sure which of them is better, because... this is the same as arguing which is better: Beeline, Megafon or MTS. Each radio amateur, in the process of working with SDR receivers, chooses his own over time. We recommend using the HDSDR program to start getting acquainted with the SDR receiver. By the way, there is also a program on the driver disk included with the receiver, but it is complete rubbish, believe me)).

1. So, download and install the HDSDR program http://www.hdsdr.de/index.html At the time of writing this article, it is current and stable version programs 2.76, direct link: http://www.hdsdr.de/download/HDSDR_install.exe Direct link from Yandex disk, if the official website does not work for some reason https://yadi.sk/d/6Gd2bCjk3RCbqV

2. After completing the installation of the program, DO NOT run it! There will be a checkmark there that says “run” - uncheck it. In order for the program to see your receiver, you need to download DLL file, this one http://hdsdr.de/download/ExtIO/ExtIO_RTL2832.dll Direct link from Yandex disk to the same file https://yadi.sk/d/5KZTA-K53RCbzZ

3. This file must be placed in the folder where you installed the HDSDR program. (default C:\Program Files\HDSDR, or C:\Program Files(x86)\HDSDR)

4. Next. It is necessary to download the second DLL file, with the help of which it will be possible to receive radio amateurs directly. Link to file https://xa.yimg.com/kq/groups/82400279/47992593/name/ExtIO_RTL_SW_Patch.dll Direct link from Yandex disk to the same file: https://yadi.sk/d/t7XPc0HO3RCcBP

5. It also needs to be placed in the folder where you have the HDSDR program (by default C:\Program Files\HDSDR, or C:\Program Files(x86)\HDSDR).

Now, let's configure the HDSDR program itself

1. Launch the program from the shortcut on your desktop. At the moment of launch you every time a window like this will appear

This is a window in which the program seems to ask you - which DLL should I work with? To begin with, select the patched DLL, that is, SW_Patch. With this DLL, your SDR receiver will be able to receive radio waves from approximately 3 to 12 MHz, that is, radio hooligans on 3 MHz and two amateur bands 80m and 40m. Then, when you purchase or solder the converter yourself, you will run the program using a regular DLL.

2. So, the HDSDR program has started and, if you previously did everything exactly according to the steps, as we wrote, you will hear the noise of the air, your SDR receiver is working! Connect your antenna and try tuning to a station

3. Program for English, but, intuitively understandable. Most importantly, remember this path in the program settings: Options / Misc Oprions / Reset to factory settings. This is a function that resets all program settings to factory settings. You will definitely need it to reset settings when you experiment;)

That's all. In the following articles we will share our experience with program settings.

Turn any phone or tablet into a portable software-defined radio (SDR) with a spectrum analyzer. Listen to and record FM radio stations in stereo along with RDS, weather forecast, emergency services, taxi drivers, analogue television sound, ham radio, digital broadcasts and much more! Depending on the equipment you use, the frequency band can vary from 50 MHz to 2.2 GHz (to receive below 50 MHz, you need an up-converter to help receive signals from 100 kHz). The following types of modulation are currently supported: FM, AM, NFM, USB, LSB, CW.

The built-in RDS monitor allows you to see hidden data digital data transmitted by FM radio stations. Among them, we accept data type (PTY), broadcast country (ECC), date and time (DT), unique station identifier (PI), alternate frequency (AF) list and advanced RDS digital signal information.

SDR Touch receives radio broadcasts using a USB receiver. The application works offline and does not require an Internet connection! SDR Touch will allow you to catch an interesting radio broadcast anywhere!

To start using SDR Touch, you will need:

USB digital terrestrial television (DVB-T) receiver based on the RTL2832U chip. You may already have one. Even if you don't have one, you can buy a new one for less than $20.
-USB OTG (On-The-Go) cable - used to connect a USB receiver to your Android device.

Connect the USB receiver to USB-OTG, then plug the free end of the cable into the USB port of your device and launch SDR Touch! It's very simple! Now you can listen to live FM radio even if your device doesn't have a built-in FM tuner!

The application is under development and may be unstable. Please let us know if you find any errors on email address specified in the certificate.

Using the RTl2832U driver, you can use the following DVB-T USB receivers:

Generic RTL2832U (e.g. hama nano)
- ezcap USB 2.0 DVB-T/DAB/FM dongle
- Terratec Cinergy T Stick Black (rev 1)
- Terratec NOXON DAB/DAB+ USB dongle (rev 1)
- Terratec Cinergy T Stick RC (Rev.3)
- Terratec T Stick PLUS
- Terratec NOXON DAB/DAB+ USB dongle (rev 2)
- PixelView PV-DT235U(RN)
- Compro Videomate U620F
- Compro Videomate U650F
- Compro Videomate U680F
- Sweex DVB-T USB
- GTek T803
- Lifeview LV5TDeluxe
- MyGica TD312
- PROlectrix DV107669
- Zaapa ZT-MINDVBZP
- Twintech UT-40
- Dexatek DK DVB-T Dongle (Logilink VG0002A)
- Dexatek DK DVB-T Dongle (MSI DigiVox mini II V3.0)
- Dexatek Technology Ltd. DK 5217 DVB-T Dongle
- MSI DigiVox Micro HD
- Genius TVGo DVB-T03 USB dongle (Ver. B)
- GIGABYTE GT-U7300
- DIKOM USB-DVBT HD
-Peak 102569AGPK
- SVEON STV20 DVB-T USB & FM and others on the same chips
- SDRplay RSP
- HackRF One
- Rad1o
- HackRF Jawbreaker

Note: If you have an Android device (version 3.1 and below), then it must be rooted and USB host enabled.

Your use of SDR Touch is at your own risk and you should check your local laws prior to downloading and use. The creators of SDR Touch are not responsible for any consequences of incorrect use of the application.

Developer: Martin Marinov
Interface language: English, Russian
Compatibility: ™ 2.3.+
State: Full version
Screenshot: Original by Dymonyxx

To use the application you need:
device with USB host support
compatible USB TV tuner
driver for connecting a tuner (installed separately; the application itself suggests downloading from the Play Store from the same author)
for devices with versions younger than 3.1, as well as in exceptional cases - root

List of compatible tuners:
FM+DAB USB DVB-T RTL2832U+R820T
Generic RTL2832U (e.g. hama nano)
ezcap USB 2.0 DVB-T/DAB/FM dongle
Terratec Cinergy T Stick Black (rev 1)
Terratec NOXON DAB/DAB+ USB dongle (rev 1)
Terratec Cinergy T Stick RC (Rev.3)
Terratec T Stick PLUS
Terratec NOXON DAB/DAB+ USB dongle (rev 2)
PixelView PV-DT235U(RN)
Compro Videomate U620F
Compro Videomate U650F
Compro Videomate U680F
Sweex DVB-T USB
GTek T803
Lifeview LV5TDeluxe
MyGica TD312
PROlectrix DV107669
Zaapa ZT-MINDVBZP
Twintech UT-40
Dexatek DK DVB-T Dongle (Logilink VG0002A)
Dexatek DK DVB-T Dongle (MSI DigiVox mini II V3.0)
Dexatek Technology Ltd. DK 5217 DVB-T Donglev
MSI DigiVox Micro HD
Genius TVGo DVB-T03 USB dongle (Ver. B)
GIGABYTE GT-U7300
DIKOM USB-DVBT HD
Peak 102569AGPK
SVEON STV20 DVB-T USB & FM
The width of the range available for listening depends on the tuner used.

List of compatible devices
Motorola Droid Razr M
Ainolo Novo Flame
Nexus 7
Prestigio 5580c
Samsung Galaxy S3
Samsung Galaxy Note 2
Samsung Galaxy Nexus
Google Nexus 4
Asus Transformer TF101
Galaxy Tab2 GT-P3110
Nexus 10
Asus Transformer TF700
Motorola xoom MZ601 Droid 4.1
Acer Iconia A500
Ritmix RMD750
AMlogic based MINI ANDROID USB PC
Samsung Galaxy Tab 2 GT-P3113
Samsung Galaxy S2
ICOO D70W
Zopo ZP100
Mobistel Cynus T2
Versus 7
Geness GT 1230
PIPO Smart S1
Allview Alldro p3
MK 802
Samsung Galaxy tab 10.1 p7510
Samsung Tab2 GT-P5100
Samsung Galaxy Note 10.1
Ainol Novo 7 Aurora
Samsung Galaxy GT P6800
Sony Tablet S
Cnm 7 touchpad
Moto atrix
almost all devices with