Featured Post

Sonified ELF signals from California, Hawaii and Virgin Island locations with 16x frequency shift

Much of my ELF measurement was done at my home using a 150' pine tree as antenna. During the recording, there was a power failure at 30s...

Saturday, October 21, 2023

Forwarded my Integrated-Vision.com domain to this Blog page.

Godaddy stopped providing hosting many years ago,  I was mad at them for dropping it,  so I didn't have website.  

My plan is to create an official site, with access my library of ELF reading, which is spotty, but does cover several years of measurements.  Mainly with the same receiver.  

For now I only have the important ones available in this blog.  See previous entries for reading that I have sonified.

The ELF receiver has a 3.3V level asynchronous serial output at 9600 baud.  It can be connected to almost any computer using a USB serial converter.  The ones I use have 3.3V and 5V sources and you jumper the Vcc of the converter to the 3.3V. The 5V source is also sent to the receiver to power it.  

The host computer controls the amplification and DC offset of the signal, along with the sampling rate.  The gain of the unit has a range from 28 to ~40,000 times  Some of the gain. up to 32x, can be provided by the TI MSP430F2013 microcontroller which also does the 16bit analog to digital conversion.  Power and serial data are connected to the unit using RJ11 4 conductor telephone cable.  I've been running mine with about 70' of cable between the receiver and my raspberry Pi.  The serial lines can be directly connected to the GPIO pins for /dev/serial0, but I use the USB dongle to protect the board.  

The control software is written in Python and ran in a Jupyter Notebook on either a Raspberry Pi or PC computer. Jupyter was great for experimentation but not for automation.  Notebook has FFT for a small window, 3d FFT plot for entire measurement and spectrogram.  

Also working on a portable communications unit, based on a ESP32 microcontroller board that has WiFi and LORA wireless connectivity.

The received signal can be displayed on the OLED display, saved to micro SD card or published over WiFi to a Mosquito broker. 

I have a Python application on my android phone, that subscribes to the data and plots both the raw signal and a 4 sample running average.  The averaging effectively removes the 60 Hz noise.

Since the received frequencies are so low, ~5 to 40 Hz, I further process the audio to pitch shift it by 16 time (4 octaves) so it can be heard.  

Tuesday, May 23, 2023

Sonified ELF signals from California, Hawaii and Virgin Island locations with 16x frequency shift

Much of my ELF measurement was done at my home using a 150' pine tree as antenna.

During the recording, there was a power failure at 30s in that ended at 54s.

See previous post for all the gorey details.

This version has the frequency shifted by 16 times, 4 octaves, to make it more audible.

Sonified 16x during power failure 

Additional ELF reading using the new portable ELF receiver and ESP32 based controller.

Waimea canyon lookout parking lot

 using myself as antenna with belt.

Map of location: 22°04'17.3"N 159°39'43.9"W

Sonified audio: 2023-04-22-02_11_30-Waimea

Top plot: Signal plot, green raw and red filtered. 

Bottom plot is frequency spectrum of first ~2 seconds of signal

FFT 3D plot of entire signal, X axis is frequency, Y axis is time and Z is strength.

Blue Beard's castle, St. Thomas, Virgin Islands, USA, 

On 2023-05-12 18:47, also using belt and myself as antenna on the roof.  The receiver is using 

Map of location: 18°20'25.1"N 64°55'26.8"W

Sonified audio: 2023-05-12-18_47_28-BlueBeardsCastle

Sandy Cay, British Virgin Islands

On 2023-05-18 07:36, using belt on small palm tree with 3 times around as antenna.

Sonified audio: 2023-05-18-07_36_09-SandCay

Map of location: 18°26'11.7"N 64°42'39.3"W

Picture of palm tree on Sandy Ca, there were 5 palms visible on east side and this was the north most and easiest to reach barefoot. The hermit crab that lived under wasn't to threatening.  

Plot of one of the readings:

Wednesday, March 29, 2023

Sonification of Extremely Low Frequency signal

Extremely Low Frequency radio receiver update

After all these years, I finally have a good recording of the Extremely Low Frequency (ELF) radio signals. 

I use a 100' tall pine tree in front of my house as an antenna, by wrapping it with a coil of wire.  Unfortunately, there is a power pole right across the street from it.  So I mainly see 60Hz power signals with some extra wiggles in it.

I have a very good way of removing the power frequency and get a signal that is around 1/10th of the raw signal.

The Schumann frequencies are approximately: 7.8, 15,6, 22 and 28 Hz.  I can see these frequencies, but when I look at the spectrograph, I was expecting to see continuous bars at these frequencies, but they come and go.   

To get a better feel of the signal, I tried to listen to the filtered recording, but it was much too low in frequency, even with headphones.   If I speed up the playback It makes a very interesting sound, because frequencies of the signals are increased to the hearing range.  Of course it loses its timing.  I had taken an online Stanford class, actually from a Spanish university,  Universitat Pompeu Fabra, Barcelona Music Technology Group, where they provided Python code that allows shifting the frequency of a signal to higher frequencies using a sinusoidal model.  I use these tools to upscale the frequency 8 times.  So a 5 Hz tone would become 40 Hz, etc.

During the first atmospheric river storm, we had a short blackout for ~30 seconds.  My house has a solar battery power backup, I recorded the event.  

I always wondered if the signals I was recording were just noises from the power line, because they are quite chaotic.  But now I have a signal with greatly reduced power line noise, still some, because I had power.

In the attached a 2 minute recording, it starts with the power on, after 30 seconds the power is off, until 54 seconds, when power is restored.  

The top plot shows the raw signal in green with the 60 Hz filtered signal in blue.  The blue signal, while reduced, is still there with the power off. 

The middle plot shows a small zoomed 2 second section of 2 the minute recording, which is the filtered signal.

Under it is a frequency spectrum for that 2 seconds.

Here is the Sonification of power failure with 8 times frequency shift, 3 octaves, as a playable 2 minute wave format file.

I had to increase the sample rate from 240 sps to 8000 sps in the sonified version to support the higher frequencies  There was quite a bit of noise as the power glitched before going off.


Found a python package that uses FFT to shift the pitch of the signal.  I've switched to doing 16 times, 4 octave shift: Sonified 16X audio

Friday, January 11, 2019

I'm back!

After ignoring this blog for a decade, I've decided to post to it again. 
Because it seems to be a place that has survived all these years of inactivity, intact.  Many of my other places to store information have become obsolete, like my personal Mediawiki and Drupal sites, where I have to do migrations to keep their databases.
I will try to explain why I stopped using the blog someday, but not now.

There are many things I want to talk about and need a public facing site to allow comments, to point out flaws in my arguments. 

  • Projects I am working on
    • Ground effect skimming boat, SkimCat.
      • Catamaran hull, actually based on Sea eagle inflatable sail cat 14 
      • Retractable hydrofoils to lift hull out of water
      • Large cord wings to fly over the water 
      • Center cockpit that also acts a wing
      • Multiple small propellers with differing pitches to spread noise frequency
      • Flight computer control to provide level flight event in choppy water.
      • Electric motor, with hybrid battery and 
    • Extremely Low Frequency radio receiver for Schumann Resonance monitoring
      • Uses tall tree as antenna
      • Synchronous sampling to eliminate line frequency interference
      • Remote operation using either: WiFi, bluetooth or LORA for command and data
      • Web based access of live signals from the various locations
  • Old projects that can be revived
    • Sterling Engine
      • I was stuck with leaky piston seal bags and was looking for better material samples.
      • Advanced sealing bag design using composite materials, perhaps using graphene. 

Sunday, July 12, 2009

Urbanmover Electric Bike, UM-44

Urbanmover Electric Bike, UM-44

Just bought one from Costco in Santa Cruz. It was a little tricky selecting one that had the right chain lock key. Had to adjust the front brake cable tension and the placement of the bell and power indicator.

  • Lithium Ion 26-Volt, 9 Ahr Battery from Panasonic. Key locked to frame.
  • 250-Watt brushless rear hub motor
  • Torque sensor in pedal crank that controls the motor
  • 43 lb including battery
  • 6 speed rear gear set with indexed shifter
  • Puncture resistant tires 26 x 1 3/8 with self sealing tubes
  • Zoom seat post suspension
  • Big soft seat
  • Integrated dual locking system, both chain and rear wheel lock, 2 keys
  • Mudguards
  • Al rear rack
  • Tool kit
  • Charger
  • Costco item # 366890
  • Manufacture's web site for UM-44

Contact info
United Kingdom

Head Office
Urban Mover Ltd
Unit 1F
Lansdown Industrial Estate
Gloucester Road
GL51 8PL

T: +44 (0)1242 254 540
F: +44 (0)870 766 5173
E: sales@urbanmover.com

USA - California

Full Boat Trading

8717 Sonoma Highway
California, 95452

T: + 1-707-736-6181
F: + 1-707-935-7103
E: info.us@urbanmover.com

Charged battery over night and took it on a 11 mile ride.
After around 8 miles the fifth battery indicator LED would start going off when I was pedaling hard. After the 11 miles, the forth LED would blink a little. Considering my weight and how hard I pushed it, the battery seems to be holding up well.

I am using a GPS as the odometer for now, until I can add a dedicated bike computer.

The 250 W motor has suprising torque. It really helps getting you going from a stop. It also helps going up easy grades. On steep hills it still doesn't have the power it self, but does help keep you going.

Saturday, November 8, 2008

New Kodak Z1015 IS digital camera

The picture below was taken with the Kodak Z1015 IS camera using maximum ISO: 6400, 3.1 Mpixel, maximum zoom: 420mm using a tripod, during a night game under the lights. I should have set the focus mode to center, it was in area mode, so the players in the foreground are in better focus then the kicker.

I have been using a borrowed Nikon D60 DSLR with a 200-500 telephoto lens to take pictures at my son's football games. While the sun was out, it took great pictures, only after it got dark out and the field lights did things get blurry. The owner of the camera was going on a trip, so I had to return the camera and had to stop being photographer for the team.

The game this week needed a photographer, so I broke down and bought a new Kodak Z1015 IS camera from Newegg, because they have very fast delivery. I was originally looking at a Costco.com ad for this camera and it seemed to have most of the features I needed. Especially the high ISO settings of 3200 and 6400, needed for the low light conditions under the lights. The lens also was pretty fast 2.8 - 5.4 for the 28 - 420 mm equivalent zoom range.

Most of the reviews for camera were good, except for the fact it can be slow to save the pictures, when in auto mode. There is suppose to be fixed in a firmware upgrade, where the post processing can be turned off, to speed click to click time. See below for more details.

I received the camera yesterday morning (Friday), after ordering on Thursday morning with next day delivery. New Egg had a bonus of adding a 2 gig SD card and a large camera bag, with plenty of room for the charger and cables.

First impressions:
1. I can hear image stabilization motors. They are not loud, but noticeable in a quiet place. It is nice to know it is working.

2. The manual focus adjustment is a little coarse, it automatically zooms the view finder 2x to help see the focus.

3. USB style charging cable with AC adapter (5V, 1A). I love this, even though they do not recommend connecting it to computer. I already have some 12VDC adapters, that may allow me to charge the camera in my car. I am also considering using making an auxiliary battery pack with a switching regulator and 9.6V battery pack. That way I can carry it in the camera bag to charge it during the game's half time without having to search for AC power.

Update: I had a TI step-down switching regulator evaluation board, that has a 5V DC output with input voltages between 10-18 V at 3 A. I am using it with 9.6 V nicad remote control battery packs as an auxiliary power source because it has a good efficiency . The camera actually pulls ~0.6 A while charging, less when turned on(?), so the regulator runs OK down to 9 V input. I can fit both the battery pack and regulator in the camera bag, so I can attach it during the game if needed.

1. The first thing that throw me for a loop is that the electronic view finder goes blank when the pictures are taken. I was used to the DSLR where the optical view finder would blank during the actual exposure, but even while the picture is being stored I could still follow the action. The Kodak would go blank until that picture is stored and the camera is ready to take the next picture. Even in burst mode, you can't see what you are actually taking pictures of.

2. There is a longer delay between shots. So between not seeing the action and having to wait and get a new focus lock, it is harder to take the picture of the pass and catch.

3. The motorized zoom buttons are on the same hand as the shutter release. But worse, you can not change the zoom while you hold down the shutter button to get focused. The Nikon had a manual zoom, which I would turn with my other hand and had complete control. So again it is slower to follow the action and get good framing.

4. In order to use the higher 3200 and 6400 ISO setting, you have to reduce the resolution to 3.1 M or below. The Nikon 200-500 had a higher aperture of 5 to 8, the Kodak 1015 with its 28–420 mm (35 mm equiv.) f/3.5–5.4 also gave it more of a speed advantage. So the players were less blurry and I could catch the ball in the are with only a little smearing. If you are going to use the flash, be sure to go back to a lower ISO.. In hindsight all I had to do was go to Auto mode.

5. The Kodak has a quick click to capture time, so once I got used to blanking, I could catch the ball in the air for laterals and fumbles.

6. I brought a tripod, but it turns out I forgot to remove the shoe from the other camera's telephoto lens. So I couldn't attach the camera to the tripod. My first couple of shots I tried free hand with the image stabilization. Even while it was still pretty light out, there was still some smearing. After a while I used the tripod by just holding the camera to it while shooting. This seemed to work well.

7. Battery life is hard to judge, because I had the firmware update problem, see below, so I couldn't turn off the camera to save power. I had also charged the battery during half time. In the 4th quarter I turned off the stabilization conserve power. I did make through the game with 191 shots, some with flash. I even took a few seconds of HD video, but I did't quite know what I was doing.

Firmware upgrade:
Since I was concerned with the click to click time, I downloaded the firmware update,. It is quite easy to install it even without loading the Easyshare software, as long as you can write to the SD card directly. You save the update in a SYSTEM directory and put the card back into the camera. When you cycle power to camera, it will detect the update and check the battery level then ask you if you want to upgrade.

Unfortunately for me, the update failed. So every time I turn the camera back on, it sees the update and if the battery is not completely charged, turns itself off. So when it was half time and it turned the camera off, it refused to come back on, until I could find a power plug on one of the light towers that worked. Because I didn't have a computer with an SD card adapter, I couldn't remove the file until I got home.

I have to admit it is a little unfair to compare this Kodak camera with a Nikon DSLR, that costs at least 3 times as much, but that was what I was used to. Although it will take some getting used to, this camera did perform well for taking picture of a night football game. It may miss some of the shots I would have captured using a DSLR camera, but the low light capabilities more then made up for it.

I will update this posting, again after the next game. One thing if found useful is the Setup->Orientation Sensor. Turning that one will automatically rot pictures taken with the camera vertical, so you don't have to go through them later and do it manually.

Thursday, August 7, 2008

Created new blog just for Open Stirling Engines

Having my personal stuff mixed in with the Stirling engine project was awkward, so I created a new blog just for the engines. It is http://openstirlingengine.blogspot.com and I will start to post my prototype status reports there. Please make comments on that site, rather the this one. Also please visit the official Open Stirling Engine project site