Quick Network Bridge Gets Off-grid Home Back Online

Off-grid living isn’t for everyone, but it has gotten easier in recent years. Cheap solar panels and wind turbines let you generate your own power, and there are plenty of strategies to deal with fuel, water and sanitation. But the one thing many folks find hard to do without – high-speed internet access – has few options for the really remote homestead. [tlankford01] wants to fix that and is working on an open-source mesh network to provide high-speed internet access to off-grid communities.

But first he had to deal with a major problem. With high-speed access provided by a Clearwire wireless network, streaming content to his two flat-screen TVs wasn’t a problem. At least until Sprint bought Clearwire and shut down the service in early November. Another ISP covered his area, but his house lies in a depression out of line of sight of their tower. So he rigged up a bridge between the WiMAX network and his lab. The bridge sits on a hill in sight of the ISP’s tower 3.5 miles away. Solar panels, a charge controller and deep-cycle batteries power everything, and a wireless link down the hill rounds out the build.

This is obviously a temporary solution, and probably wouldn’t last long in winter weather. But it’s working for now, and more importantly it’s acting as proof of concept for a larger mesh system [tlankford01] has in mind. There are plenty of details on what that would look like on his project page (linked above), and it’s worth a look too if you’re interested in off-grid connectivity.

Theremin’s Bug: How The Soviet Union Spied On The US Embassy For 7 Years

The man leaned over his creation, carefully assembling the tiny pieces. This was the hardest part, placing a thin silver plated diaphragm over the internal chamber. The diaphragm had to be strong enough to support itself, yet flexible enough to be affected by the slightest sound. One false move, and the device would be ruined. To fail meant a return to the road work detail, quite possibly a death sentence. Finally, the job was done. The man leaned back to admire his work.

The man in this semi-fictional vignette was Lev Sergeyevich Termen, better known in the western world as Léon Theremin. You know Theremin for the musical instrument which bears his name. In the spy business though, he is known as the creator of one of the most successful clandestine listening devices ever used against the American government.

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A Structural PVC Cyr Wheel

PVC is a great building material that can be used for everything from yurts and geodesic domes to pressure vessels. One thing we haven’t seen a lot of is bending PVC pipe. [Lou] wanted to build a Cyr wheel for his daughter, and instead of shelling out five hundred big ones for an aluminum version, he build one out of PVC using techniques usually reserved for woodworking.

A Cyr Wheel is usually a large aluminum hoop built for acrobatic performances. These performances are pretty impressive and look like a lot of fun, but the wheels themselves are rather expensive. Figuring PVC was a good enough solution, [Lou] built his own Cyr wheel for $50 in materials.

The build started off by laying out a jig on the floor. Two sheets of plywood were laid out, a radius for the wheel traced, and a bunch of blocks were glued to the perimeter of this mold. With the mold in place, a few pieces of PVC were flexed into position, clamped, heated with a hair dryer to relieve stress, and glued to a second course of PVC.

The process [Lou] used to build his Cyr wheel isn’t that different from extremely common woodworking techniques. In fact, it wouldn’t be unreasonable for [Lou] to build a wooden Cyr wheel with the same jig. We’re wondering how well this project will stand up to abuse, so if you have any insight to the uses of structural PVC drop a note in the comments.

How To Be The Hardware Engineer At A Startup

For those who prefer the smell of solder smoke to lines of code then you may be a hardware engineer. What you should consider is how to land a job at a startup, how to work fast, be a team player, keep an open mind, and be organized. Joining a startup will be the greatest challenge of your career. You can do it! Be a hardware engineer at a startup and change the world.

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The Death Of Surplus

I thought the surplus electronics market in Dallas was a byproduct of local manufacturing, after all we have some heavy hitters in our back yard: Texas Instruments, Maxim (Dallas Semiconductor), ST Micro (at one time), Diodes Incorporated. If we widen our radius to include Austin (3 hours down the road) we can make a much more impressive list by including: National Instruments, Freescale Semiconductor, better yet I’ll just insert the graphic I’m pulling data from right here:

texas_companies_map
Texas Electronics Map Source: Texas.gov

Granted, not all of these are companies that manufacture silicon, or even have manufacturing facilities here in Texas. That doesn’t necessarily matter for surplus to exist. Back to my point of where surplus originated. While I wasn’t completely wrong (these companies certainly have helped contribute to the surplus electronics market) the beginnings of surplus storefronts date back to World War II. Did anyone see that coming? Neither did I. However it does make sense, the US government would have had a large stock of “stuff” to get rid of at the end of the war.

Enter the sale of government surplus all over the nation, usually near air force bases. So this is how the more generalized concept of a surplus shop came to be in existence; mix in the domestic manufacturing of electronics in the 1970’s and we have electronics surplus shops aplenty.

My First Hand Experience

I didn’t really appreciate how valuable my local electronics shop was until watching Beers in Bunnie’s Workshop – Workshop Video #36. If you haven’t seen the video you only need to know that [Ian] of Dangerous Prototypes and [bunnie] of Andrew [bunnie] Huang are standing in [bunnie]s work-space in Singapore drinking beer and talking about the lab that is [bunnie]s life. You with me now? Okay, there is a point in the video where the two discuss the ability to run down the street and buy a connector as something only available in Singapore or Shenzhen. Let me briefly pause here to clarify that I’m not comparing my local electronics shop to the Shenzhen market or Sim Lim Tower in Singapore, only stating that I too can hold parts in-hand before purchasing them. I’m also not [brandon] of Dangerous Prototypes or Andrew [brandon] Huang, clearly.

I do however have an electronics selection at my disposal that is unmatched until you get to the west coast shops. I went on a bit of an adventure with the owner [Jim Tanner] of my local shop [Tanner Electronics] to take some pictures of the retail floor and a few behind the scenes (warehouse) shots that you can check out after the break.

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Shark Vs. Robot

In laymen’s terms they built a shark-chasing robot. You can guess what happened next…

The back story is a little more reputable. I recently attended the Center for Marine Robotics meeting at the Woods Hole Oceanographic Institution (WHOI) and learned about a very interesting robot. For the Discovery Channel’s Shark Week the network partnered with [Amy Kukulya] at WHOI to develop an autonomous underwater vehicle (AUV) that locates, follows, and films sharks in their natural habitats, swimming, patrolling, doing their thing.

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Pi Zero Ethernet The Hard Way

[Alex@Raspi.tv] had the misfortune of blowing the USB hub and Ethernet port on a Raspberry Pi B+. He thought about using a cheap SPI to Ethernet board to rescue it, and while he bought the board, he never got around to interfacing it to the broken Pi. However, when he saw the Raspberry Pi Zero arrive and noticed that everyone wanted to connect it to the network, he remembered the SPI board, rescued it from his junk box, and a few hours later had Ethernet via Raspberry Pi GPIO working.

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