I have collected a bunch of old Raspberry Pi model B’s equipped with the Wolfson audio board. You may find these board lying around and collecting dust, as they have been obsoleted by an increasing number of multi-core boards. I will use these boards as simple Softrock SDR receivers, but first I want to do a little experiment. I am going try using them as a headless FreeDV modem similar to the SM1000.
Few days ago, I have been playing with CuteSDR on Linux and Mac and came to think, would this work on a Raspberry Pi? While there is nothing conceptually impossible about running CuteSDR on the Raspberry Pi 2, I often run into obstacles trying to port Qt application to embedded devices, so here are my notes about how to make it work.
In a previous post I wrote about using the UT-100C DVB-T modulator on linux and I promised to follow up how to use the modulator with live video sources. In this post I am going to describe how to setup the modulator on a Raspiberry Pi equipped with a RaspiCam camera module, effectively turning the Pi into a live HDTV transmitter.
Building the UT-100 driver module on the Raspberry Pi can be done the same way as on the desktop. The only difference is that instead of “sudo apt-get install”-ing the kernel headers and sources we have to fetch them from the Raspberry Pi git repository and install them manually. Although my instructions are written with the UT-100C DVB-T modulator in mind, the procedure is applicable to other out of tree kernel modules as well.
In October last year I learned about the UT-100 series of DVB-T modulators available from a company in Taiwan. At that time I have already been working with software defined video broadcasting; however, I still found the idea of a small USB-stick modulator very appealing for use with embedded devices. In this post I have collected my notes about setting up and testing the UT-100 modulator on Linux.
Today I have spent some time trying the Funcube Dongle with Quisk SDR. The setup procedure was quite painless and the results very satisfactory: Using an Arrow II hand-held yagi connected directly to the FCD I could receive the HO-68 CW beacon with very good SNR.
It looks like Moe Wheatley, AE4JY, is working on a cross platform software defined radio receiver intended for SDR hardware from RFSPACE. It is written using the Qt toolkit and will be available soon under an open source license with the purpose of providing an SDR interface program example for other developers. It is still very early and no code has been released yet, but you can watch this first demo video published few days ago and you can also join the CuteSDR Yahoo group if you are interested in following the project.
The way I achieved it was by configuring Fldigi to capture its data using the built-in microphone and turn the volume in Web SDR up until it was sufficient. The result was surprisingly good; of course partly because the Mac has relatively good sound hardware – at least when compared to some standard PC sound chip.
I prepared this video demonstrating how it works. You will hear and see many PSK-31 stations as well as some RTTY and other modes. Enjoy and have fun.
Watch in high resolution.