There are 4 videos on Youtube by “Franz DX”, that showed an impressive small and still interesting standalone SDR, start with video #1 That videos inspired me to think about replica or derivate projects.
With my first quick setup I was very surprised. It performed much better, than I would an arduino-like platform expect to perform and that is mainly due to the 32 bit Cortex-M4 based board in combination with the SGTL5000 Audio board. It simply beats the computing capabilities of the – standard – Arduino in quite all points. CPU, Memory. Also there is a very active community around it chatting and helping each other in the forum. The extra memory makes it a 2016-ish feeling and the 96 MHz are great for all sort of calculations!
The creator and many contributors have built up an excellent C++ based library ecosystem around the platform, that makes it easy to take off in no time. That said, most of them are actually the arduino libs, with some tweaks. That saves you a lot of time when driving some accessory devices like LCDs etc. Especially the audio library is worth a look. The workshop video is fun to watch!
Personally I don’t like the Arduino IDE, because it tries to hide a lot of “complexity” of the underlying language. Might be nice for beginners or a short sketch, but not so cool when you’re about to put serious effort into development. Therefore I prefer to wrap Eclipse for Arduino around the Teensy/Arduino libs and build tools. It simply gives you a solid editor, common IDE features and doesn’t force you to work in a notepad style with this .ino skatches. Simply pure C++, as it should be. The How To section will guide you to set it in place for Teensy development. Since I’m bit a Jetbrains fanboy I’d like to see a CLion wrapper around the avr tools that actually work. I’ve used eclipse for many years and it’s just a not my number 1, but not a bad choice, since it allows good IDE aided development flow for the entire development life cycle.
Currently I’ve got a reasonable long list of SDR projects, that I’m doing some good progress on. I’m not about to jump right into a new project based on the Teensy, but it’s good to have it in the toolbox. It’s value for the hobbyist as a development platform is worth the price. So expect it to approach here and there in my future projects.
One new fun-project will go to my list: Combine the famous C64 SID 6581 chip – with all it’s analog, non linear unique sound – with some tiny DSP. Guess that’s a perfect math and think about the nice synthesizer samples, generated realtime on the SID! Non HAM project, I know, but in the end all is about waves 😉
Here is a first short video about my initial setup with a FFT on a post stamp oled display. Just ordered a higher res color SPI display, that should manage 30 frames per second.
08th Aug 2016: Updated the display and code: