Take a Beaglebone, add an LCD cape and a £10 USB TV dongle, install librtlsdr and my rtlizer software and you have an awesome hand-held, real-time spectrum analyzer.
The Funcube Dongle Pro and Pro+ on the Raspberry Pi
Although I have had a Raspberry Pi rev B for several weeks now, it wasn’t until last night that I got a chance to try it out. Since several people have reported failed attempts at getting the Funcube Dongle Pro and Pro+ play nicely with the Raspberry Pi, I decided to take it as far as I could in those few hours. The result is this very brief tech note about how to make the Funcube Dongle Pro and Pro+ work on the Raspberry Pi.
Hardware AGC in RTL-SDR devices
I was testing the Gqrx FM stereo code by Alex Grinkov using an RTL-SDR dongle when I noticed that the recently added auto-gain in the driver can be quite useful.
NOAA APT reception with Gqrx and rtlsdr
About a year ago I posted a step-by-step guide about how to receive NOAA APT weather satellite images using Gqrx SDR and the Funcube Dongle. Today, I tried to repeat the procedure using my ezcap eztv666 rtlsdr dongle with very good results.
Turning the Beaglebone into a high definition IP camera
Few weeks ago I posted some notes about using the Logitech HD Pro Webcam C920 with Gstreamer. I have since ported the setup to the Beaglebone, effectively turning my Beaglebone into a streaming IP camera that can deliver constant bitrate H.264 video at full 1920x1080p30 resolution without breaking a sweat.
Beaglebone booting linux in less than 5 seconds
As I was trying to find my way around building Ångstrom using OpenEmbedded, I stumbled upon as minimalistic systemd-image recipe for the Beaglebone. It boots up a usable system in less than 5 seconds.
Arduino controlled differential pan/tilt drive
An Arduino Duemilanove controlling a differential azimuth/elevation drive. The stepper motor interface is two EasyDriver boards.
Using the Logitech C920 webcam with Gstreamer
You may already know about my existing enthusiasm for Logitech webcams, which is due to the combination of relatively good image quality, high resolution and easy to use UVC interface. I was therefore very happy to learn about their newest camera, the HD Pro Webcam C920, which in addition to the standard HD webcam stuff we already know from the C910, also provides hardware encoded H.264 video stream! This is rather new and there isn’t much software that can take advantage of it; however, with a little tweaking and hacking we can get the H.264 stream into Gstreamer, where after we can do pretty much whatever we want.
Gqrx with RTL-SDR and UHD support
Support for RTL2832U-based DVB-T dongles and USRP devices from Ettus Research is now available in the Gqrx source code repository.
Support for RTL2832U-based DVB-T devices is available via the rtl-sdr and gr-osmosdr libraries. This also provides support for Ettus Research USRP’s if the gr-uhd package has been installed prior to compiling gr-osmosdr. A complete build from scratch that would support all hardware devices would thus include the following steps:
FM transmissions over FO-29 linear transponder
I have previously written about interference from FM stations on the HO-68 linear transponder. Now it appears the other satellites with linear transponders also suffer from local FM traffic by people who haven’t got a clue that they are transmitting in the satellite uplink segment of the 2 meter band.