================================================================================ = PWN_SDR - RTL-SDR for Pwn Plug = = Tom Nardi (MS3FGX@gmail.com) = ================================================================================ pwn_sdr is a script that will install the lastest build of RTL-SDR on your Pwnie Express Pwn Plug. This includes installing the required dependencies, pulling the latest RTL-SDR from git, and running a hardware diagnostic. pwn_sdr can also start rtl_tcp, the server component of RTL-SDR, which allows you to remotely control the SDR device connected to the Pwn Plug. -------------------------------------------------------------------------------- - Requirements - -------------------------------------------------------------------------------- To use pwn_sdr, you need to have a Pwnie Express Pwn Plug, and a DVB-T tuner based on the Realtek RTL2832U chip. Ideally your device will also have the Elonics E4000 chip for the best frequency range, but that is not required for operation. -------------------------------------------------------------------------------- - Usage - -------------------------------------------------------------------------------- As of the current version, pwn_sdr supports the following arguments: install Installs required dependencies, downloads RTL-SDR, and compiles it. uninstall Completely removes RTL-SDR and its dependencies. deps Install dependencies required to compile RTL-SDR, but not RTL-SDR itself. rmdeps Remove dependencies required to compile RTL-SDR, but not RTL-SDR itself. upgrade Upgrade the RTL-SDR installation, does not remove dependencies, but does remove currently installed build of RTL-SDR. start Starts rtl_tcp to listen on the Pwn Plug's primary interface and with a set sample rate. stop Kills a currently running rtl_tcp daemon. help Prints usage information. -------------------------------------------------------------------------------- - Sample Rate - -------------------------------------------------------------------------------- I've found that, when connected to the Pwn Plug, RTL-SDR devices can't deliver the same samples rates they do on the PC without dropping data. In my testing, the best I could get without losing data was 1.7 MHz. This may be due to inherent hardware limitations of the Pwn Plug, but it would be worth trying on your own hardware to confirm. The "rtl_test" program included with RTL-SDR has a function to do exactly that. For example, a command to attempt to sample data from your device at 2.0 MHz looks like this: bash$ rtl_test -s rtl_test -s 2.0e6 Found 1 device(s): 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Using device 0: ezcap USB 2.0 DVB-T/DAB/FM dongle Found Elonics E4000 tuner Supported gain values (18): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0 43.0 45.0 47.0 49.0 Exact sample rate is: 2000000.052982 Hz Reading samples in async mode... lost at least 52 bytes The "lost at least xx bytes" line shows that we are getting errors, and this sample rate is too high. Try with increasingly lower frequencies until you no longer see that message. -------------------------------------------------------------------------------- - Remote Operation - -------------------------------------------------------------------------------- Since the Pwn Plug has limited hardware capabilities, capturing data directly on the local device is not recommended. Attempting to log data to the Pwn Plug's internal storage is likely to lock the device up. To overcome this, the best option is to use the server component of RTL-SDR, called rtl_tcp. pwn_sdr is able to start and stop the daemon by executing it with the appropriate options. Once the rtl_tcp server has been started, you can connect to it from the remote machine by entering your Pwn Plug's IP and port information into GNU Radio in the following format: rtl_tcp=192.168.1.40:1234 -------------------------------------------------------------------------------- - License - -------------------------------------------------------------------------------- pwn_sdr is released under the revised BSD license. The license, in its entirety, is within the pwn_sdr source. -------------------------------------------------------------------------------- - More Info - -------------------------------------------------------------------------------- For more information and updates, please see www.digifail.com