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I’ve built a new gadget to store electrical energy in lithium batteries for an outdoor application. It’s very simple, and it all fits in a weather tight enclosure. Here are the circuit drawing and a photo.

Circuit diagram lithium storage

Photo of assembled lithium power pack

As you can see the output is 5.1VDC, just right for a webcam or other SoC board gadget.

Of course once a build starts there is always a problem. The 18650 batteries I chose are flat tops. The battery holders have riveted connectors that were not contacting the positive terminal of the batteries. I added a small nut and bolt through the center hole of the positive terminal., with the screw head facing the battery.

By wiring pairs of batteries in series we get about 7.4V, 4 pairs of batteries in parallel increases storage capacity, and the buck converter provides regulated 5.1VDC output. The charge controller used is designed to charge 7.4V batteries up to about 8.4V.

July 8, 2017 / m4vyn

Bigger! Better! Faster! Quieter! These were all requirements for my latest PC build, a fanless 140 watt TDP hexacore Intel i7-6800K in a very quiet case. I used the largest heat sink I’ve ever seen, with enough fins for 4 dozen sharks, and some low speed ultra quiet fans. To keep up with the fast CPU there is a 512gb Samsung NVMe M.2 SSD on the Asus X99 motherboard, and it’s all verra nice.

My newest camera build is actually a rebuild of the one I put together in my last post here. I found that the Pine A64+ was drawing so much current it was dragging down even adequate power supplies, or there was too much voltage drop in the power cabling. It was too unreliable and cantankerous, so it’s gone.

To replace it I used a much smaller, less expensive, and possibly even more exotic Orange Pi One. In conjunction with Armbian (Jesse), MJPEG Streamer, and the ELP USB camera used in my previous build I created my highest resolution build yet, and it still achieves good streaming motion video.

I like the Orange Pi One, it’s easily powerful enough for a webcam. With the added USB camera and everything running the total power consumption of the new cam is 3.3 watts.

February 6, 2017 / m4vyn

You know how it is, you build a project, it works out well, then you want more. I’ve been very pleased with the two 1080P webcams I built using Orange Pi, but why not try for more? How about streaming a 6 MP image?

I found a very nice USB camera board, combined it with a Pine A64+ SoC board, used Ubuntu 16.04, installed fswebcam, compiled mjpg_streamer, and I’m using a commercial outdoor security camera enclosure.

It’s giving me images at 3264 by 2448, which is the ancient, deprecated 4 by 3 aspect ratio. Real men prefer 16 by 9, so to get it closer I hand drew a crop frame that gets it much closer, 3264 by 1848. Despite my cropping out some of the image it still is nearly 4K, and it exceeds the resolution of an iMac 27″ display.

I’m pulling about 12 frames per second @ about 10~12 mbps. The image quality and sharpness are superb under indoor lighting conditions.


Here are some pics of the major components.








November 3, 2016 / m4vyn

My latest IP Cam project relies on an Orange Pi PC SoC board and an Embest USB camera board. Thecamera board is taped to the window in my office, connected via USB to the Orange Pi, which in turn is connected via Ethernet to our LAN. The camera board creates a 2048 by 1536 video (4 by 3, how 1990!) which is later cropped to digitally zoom on our view of a freeway interchange a mile away.

On the Orange Pi I’m using mjpg_server to capture the video and offer it up as an IP stream. Post production is done on a Windows 10 PC using Blue Iris software. The resulting file is then uploaded once per minute to one of our sister sites (Geek Hill). This is done as a public service so that commuters can see the traffic situation at the Ontario Ave interchange in South Corona, CA.

Daytime images are harsh and overexposed because the camera board lacks an IR cut filter. So it goes.

The Orange Pi PC board

USB Camera Board


USB Camera Board

An image from our testing before the board was placed

Sample image shows southbound traffic jam in the afternoon

October 22, 2016 / m4vyn

Gatecam number 4 is based on an Orange Pi with USB camera board. It replaces an earlier camera made with a Raspberry Pi. The Orange Pi using UVC video and MJPEG Server produces up to 15 fps at FHD (1920 by 1080) compared to a max of 4 fps with the Raspberry pi. I used Armbian, fswebcam and MJPG server. The setup lives part way down our drive and allows us to see a driveway gate that is below the floor level of the house.

Here is a sample image.

And here is the build in progress.
















October 5, 2016 / m4vyn

I’ve switched to using metal enclosures for my Raspberry Pi webcams, here are some photos of work in progress.

There is more room and I expect long term durability.

I’ve also experimented with raspistill switches too. Here is my current command line for a webcam aimed at a freeway intersection a mile away. I’m using only a portion of the sensor to get smaller file sizes that include only the area of interest. It’s like a pre-emptive digital zoom.

raspistill --nopreview -hf -vf -w 1024 -h 576 -roi 0.4,0.4,0.40,0.40 -q 75 -o /tmp/stream/pic.jpg -tl 20 -t 0 -th 0:0:0 &

The photo with a zoom lens was a failed experiment in optical zoom.






August 8, 2016 / m4vyn

We have completed another year of net billing for our large PV solar installation. After all the math was done it turned out we were net producers of electricity again, and so we got another check. Not much money, but better than a $1000 a month bill.

During this year our battery electric vehicle (BEV) was charged only at home. And our electric bill is negative, so my energy costs for the year of driving was slightly less than zero.


June 26, 2016 / m4vyn

My first home made solar gadget involved a pair of motion sensing LED floodlights powered by a 50 watt solar panel with charge controller and 12V SLA battery. Over time I decided to add a few always-on USB-powered LED lights, so the patio is always dimly lit at night. This made the floodlights superfluous so they were removed and another Raspberry Pi webcam put in their place.

I used a large aluminum enclosure for this project, and my new method of using resistors to mount the Raspberry Pi camera to a larger circuit board. This provides a few degrees of flexibility so the camera can be rotated slightly if need to get a level horizon. For the next few months as my tomato plants grow a script will capture an image every day at about Noon. Eventually there may be a time lapse video.













February 24, 2016 / m4vyn


We ended up being net producers of electricity for our third billing year having solar power online. It was also the first full year during which we charged a Battery Electric Vehicle (BEV), which was charged nowhere else in the entire year. With all of that we still were net producers of electricity while running pumps and filters for two koi ponds (which run 24/7), a pool, and a spa. Additionally we have at least six computers powered on at all times, five DVRs, and large portions of random geeky gadgets.

Probably my best trick at keeping our net electricity usage low is to use fans instead of air conditioning at home whenever the heat is bearable. Our central air no doubt draws much more power than our EV does at peak charge point. Because we have pumps running 24/7 for our koi ponds we derived a big benefit by using energy efficient pumps.

I’m very pleased I was able to achieve one year in which SoCalEd paid us. I really worked at being energy efficient.

From the point of view of finances, the results we are getting were greatly improved when we switched to a Time Of Use rate plan designed for EV owners. We charge our car after Midnight when the rate is lowest, and since I wake up very early I often use our major appliances before dawn. We expect to break even on the cost of our solar panels in four and a half years, they will continue operating, with a gradual decline in output power, for another twenty years.

Over the course of 20 years we expect to save over $500,000. And our power generation produces no pollution at all. What’s not to like?

August 2, 2015 / m4vyn

Good News Everyone!

A long time ago on an episode of Futurama Professor Hubert J. Farnsworth invented a Finglonger, a simple binary one bit mechanical device with, obviously, two possible states. In one case, we’ll call it a space or zero, the Finglonger is open. When the operator applies sufficient squeezing mechanical energy to the handle of the Finglonger it changes state to a binary 1, we’ll call it a mark. When this state change acts on the physical layer the Finglonger closes, and material that may have been in its vicinity is likely to be clamped.

Our Samsung front loading clothes dryer is about 7 years old. Recently it was taking longer and longer to dry each load of clothes. I had the impression it was because the dryer vent hose was clogged, but then with guests in the house increasing the usage suddenly I noted that the dryer door was not closing properly.

The lint filter would not seat properly.


Lint Trap

I removed the lint filter and used the Finglonger to pull at least a dozen Finglongers full of lint out of the chute into which the filter slides.

A single bit binary device made a large analog improvement in our clothes dryer.

Once again Hubert J. Farnsworth saves the day.

June 2, 2015 / m4vyn