Monday, July 29, 2013

BladeRF arrived, just 10 minutes earlier than expected/predicted by FedEx

Ok, I received my BladeRF, in perfect condition and perfect on time!
It was delivered with 2 SMA-cables for RF in/out and a USB3 cable. No CD, no paper docs, not even a "Must read"-letter. This is 2013 and internet, I don't complain.

What are my plans?

I want to give gnuradio a try. I think that gnuradio, python and Windows should work together to get my BladeRF-GNSS-receiver running. I will use Github to keep track of my software-trials.

In the past I used to work with Eclipse and java for software-experiments. For my attempts, have a look at my old blog:

I don't want to RUN for a working GNSS-receiver, I bought one for $50, so I always know where I am. Also my smartphone can navigate and I have a Garmin in my car. No, my satisfaction comes from learning, from the process itself. And I am not in a hurry, besides, believe me, as a retired engineer I only have a few hours a day to spend on this hobby!

I want to solve my gnuradio-problems first, after that I will try to download BladeRF software in a local directory on my laptop using Github. I think I will try to play around with the FPGA with Quartus, blinking LEDs etc and meanwhile trying (in vain) to explain to my wife why this is so fun! Later I will perhaps try to get a file with real-world data from BladeRF and process that file with python or gnuradio. Or perhaps from the beginning try to do it with gnuradio in realtime? Perhaps later trying to speed up things with VHDL-coded firmware?

This small reptile (from memory around 12 cm) 
just waited patiently to be photographed in France last year

Tuesday, July 23, 2013

Ordered BladeRF; installed Quartus and GnuRadio on a laptop with Windows 7 prof

I ordered my BladeRF last week and saw today that I was already credited on my bank account. Anyway it is reassuring that my order was noticed at

I downloaded Quartus and checked for support of the FPGA on the BladeRF ==> OK

Then I installed gnuradio. First I installed Python 2.7. I did run Python on an iPad before, but that was Python version 3. For gnuradio you need version 2.7, the latest relase before version 3.

I already noticed a difference between the two pythons: you cannot simply say "print a" in Python 3. You have to write "print(a)"

Quite annoying if you stumble with python for the first time.

Now I have python 2.7 running on the laptop and I must say, it works like a charm. I read the tutorial, well, I skipped a lot of the tutorial but found the differences with other programming languages I used before. Among others: FORTRAN, BASIC, Algol, C, LISP, Pascal, Prolog and lastly Java. I thought java would be the last programming language to learn. But now I understand I will use Python from now on. Still under Windows, no linux yet. I had Debian running under VMWare but it seems my license expired. I have to solve that problem later IF I _must_ use linux. I'll try to use Windows as long as possible for this project.

Reason: my wife also uses the laptop. I invested hours in convincing her to leave MSDOS for Windows. I finally succeeded so we now have one common laptop with Windows 7 prof. I don't want to put my 40 year relation on risk by trying to convince her to go for linux...

Gnuradio is a marvelous discovery! This is exactly what I needed all the time. I looks like what you can do in Simulink with MATLAB. After reading some documentation and looking a some video-tutorials I came up with my first project and it worked almost immediately. To be honest, the example from the tutorial with an oscilloscope, waterfall display and FFT generated a lot of error-messages. I have to solve that problem later. My current hello world-gnuradio-program:

Perhaps the picture is unreadable. I can send a better version if asked for it. The left sink is a noise-generator. This is followed by a filter, a throttle and finally the sink. This output-sink is the loudspeaker on my laptop. Without the filter I hear a hiss, ok, noise. With the lowpass-filter around 800 Hz the hiss sounds as you might expect, no high frequencies anymore.

I was quite satisfied with this result. My wife did not understand my satisfaction, she will never understand why I bought that BladeRF by the way.