Daniel Rapp has written a blog post about using the doppler effect to sense motion. In his experiments he's used hand gestures in free space to generate the scroll, tap, and double-tap gestures on his laptop. He's produced a library which allows a computer to transmit a tone from its speaker while at the same time receiving through its microphone. As the hand … Continue reading Sense motion by using doppler effect
SDR
Open RF
As I continue to experiment with cheap software defined radios paired with open source software I find myself in awe of the amount of information passing silently all around us. More importantly, I'm in awe of what sharing that information with others has the potential to do. Learning and utilizing open source software are the first steps. … Continue reading Open RF
Bay-Net 4 Repeater for 12 hours
This is an image of a 1 MHz bandwidth slice within the 2-Meter Band of the Radio Frequency spectrum in San Jose, CA. The image is built from logged data over a period of 12 hours on 2 January 2015. More specifically, this image illustrates 145.000 MHz through 146.000 MHz. Left to right represents increasing frequency. Top to bottom represents passed time.
The rtl_power Results Are In
Here's an image based on the results. This area of the RF spectrum in my location is busy with San Jose dispatch, fire, and police. I've trimmed this image because not much was going on above 157 MHz.
Installing GNU Radio & rtl_power on Ubuntu 14 LTS
In continuation to my USB SDR post, installing GNU Radio was my first priority. GNU Radio (which I'm still very far from knowledgeable about) appears to allow my computer to recognize the USB SDR and grant me access to it. It can do much, much more, but that's the extent of my knowledge so far. … Continue reading Installing GNU Radio & rtl_power on Ubuntu 14 LTS
Always Overdone 