Ten Mile Raspberry Pi WiFi (with A Catch)

January 5, 2016 by Al Williams 57 Comments

How would you like to have a WiFi connection that covers 10 miles? Or how about an even wider network made up of a mesh of multiple nodes? It is possible, but there is a catch: you probably need a ham radio license to do it (at least, you do in the United States).

What makes it possible is the realization that conventional WiFi channels 1-6 are inside an existing US ham band. That means (if you are a ham) you can elect to use FCC part 97 rules instead of part 15 that governs WiFi routers. That means you can use more power and–even more importantly–better antennas to get greater range.

Traditionally, hams have used custom firmware for Netgear routers or Ubiquiti hardware. However, [WZ0W] recently posted his experience using Raspberry Pi boards as mesh nodes. The code (which also works with some other single board computers) is available on GitHub (with details on the project blog). [WZ0W] points out that, unlike using a consumer router, using a Pi provides a reasonably powerful computer for hosting services as well as hosting the network.

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Raspberry Pi + Wolfram Data Drop

January 4, 2016 by Al Williams 1 Comment

When you think of Mathematica and Wolfram, you probably think high-power number crunching. You might not think embedded systems. Wolfram runs on the Raspberry Pi, however, and there is a recent video (below) showing a Raspberry Pi, controlling I/O devices, and interacting with the Web using Wolfram data drop.

The second video, below, shows some older example projects including a simple home alarm with a PIR sensor. Not the kind of thing that Wolfram is known for, but fine as a “hello world” project. There is even a project that uses an Arduino for more I/O. Between the two videos, you can get a good idea of the sort of things you can accomplish using a Pi with the language.

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A Raspberry Pi Tidy Tide Tracker Predicts Propitious Promenades

January 2, 2016 by Rud Merriam 11 Comments

The whims of the tides can make walking near the ocean a less than pleasant experience. A beautiful seascape one day may appear as a dismal, mucky, tidal flat the next. Frustrated over these weary walks, [Average Man] created a tidy tide tracker to predict propitious promenade periods.

A Raspberry Pi A+ pulls tide timing information off the web by scraping a web page using Python code. The time for the high tide, when the estuary will be full of water, is shown on a 4-digit 7-seg display. It’s all sandwiched between two smoked black panels to provide a neat case while still letting the LEDs show through.

Wired Display Board

ProtoPal Board

The code comes from two projects [Average] recalled from a kickstarter timing project and a 7-seg display project. As he points out:

It’s great to learn programming from others, but it’s even better if you learn them well enough to remember, re-use and combine that code later on as well.

The display chips are mounted on a product of his own, the no longer available ProtoPal board. This is a Pi A+ size board with 288 prototyping holes and the standard connector for mounting on the Pi GPIO header. It keeps the project neat and clean.

Home Made Half Life 2 Turret Powered By Pi

January 1, 2016 by Richard Baguley 7 Comments

To help expand his inter-dimensional empire, [Solderchips] has decided to build his own Half Life 2 turret. This, he hopes, will automatically track and shoot anyone who hinders the work of Our Benefactors. He’s documenting the process, and has just published his first step: creating a 3D model of the turret and printing it out. The final project will use a Raspberry Pi and a webcam to track rebels and fire on them automatically, especially those with crowbars.

He’s made a promising start, using a papercraft model of the turret to build the 3D model, then modifying it to accommodate the brains (the Raspberry Pi) and the brawns, a couple of small servos that will move the top of the turret around. The next step will perhaps be to add a tilt switch so that the whole thing falls asleep if it falls over. The thing to learn from this project, is that at some point you just have to stop thinking about it and actually make something. This paper model is a big step toward success compared to carrying around the dream in your head.

We’ve seen a few Portal Turret builds and a very nice Wheatley build, but not a decent Half Life 2 turret build, so hopefully [Solderchips] will see this through to completion and release all of his files.

Art For Planespotters

December 31, 2015 by Elliot Williams 6 Comments

We don’t know art, but we know what we like. And this gizmo by [Johan Kanflo] is right up our alley.

First, [Johan] gutted an old Macintosh Classic computer and stuffed a Raspberry Pi inside. Now this is not really a new idea, but [Johan] did a very nice job with the monitor and his attention to detail shows in the rebuilt floppy-drive eject mechanism. He gives it back that characteristic “schlurp” noise.

Then he outfitted the Raspberry Pi with an RTL dongle running dump1090 software to listen to the ADS-B radio signals. The data extracted from the SDR is piped off to an MQTT server with all sorts of data about the airplanes overhead. Another script subscribes to the MQTT topic and figures out which is the closest and runs an image search for the plane type in question, publishing the results back to another MQTT topic. One final script subscribes to this last topic and displays the relevant images on the screen. Pshwew!

The end result is a Macintosh Classic that’s continually updated with whatever planes are closest to being overhead. We’re not at all sure if this is fine art, or part of the useful arts, or maybe even none of the above. But we really like the nice case job and think that using MQTT as a back-end for coordinating multiple concurrent Python scripts (on the same computer) is pretty cool.

Magic Mirror On The Wall, “Is Pi Or ESP, Fairest Of All?”

December 30, 2015 by Rud Merriam 23 Comments

“What’s the weather like, honey?” “I don’t know. Let me check the mirror.” The mirror?

Both [Dylan Pierce] and [squix] have mirror projects that display the weather. They took two different approaches which makes for an interesting comparison. [Dylan] uses a Raspberry Pi with an actual monitor behind the mirror. [squix] puts an OLED behind the mirror driven by a ESP8266. It appears there is more than one way to hack a mirror, or anything, which is what makes hacking fun.

Raspberry Pi Booting

Framing Mirror and Monitor

[squix] started with a picture frame, adding tinting film to the glass so it would reflect. A small section of tint was removed to allow the OLED to be seen. The ESP8266 software connects to the Weather Underground to get the latest information.

The Raspberry Pi version by [Dylan] puts a 27″ monitor behind the mirror. That is either terribly impressive or way over the top but seeing Linux boot behind the mirror makes it worth the effort. The Pi generates a web page which makes this adaptable as a general purpose kiosk.

A video of [squix]’s mirror in operation, after the break.

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Yet Another Pi Zero USB Hub

December 30, 2015 by Brian Benchoff 16 Comments

The Raspberry Pi Zero was back in stock at Adafruit this week – for about eight minutes. That means a few more people get Pi Zeros, many more will put them up on eBay, and everyone is working on their own version of a Pi Zero USB hub. The latest version of a Pi Zero hub comes from [Nate], and he’s doing this one right. His Pi USB adapter adds four USB ports and features not found in other DIY USB hubs like fuses and ESD protection.

As with other Pi Zero USB hub add-ons, this build relies on a USB hub controller, a few passives, and not much else. The chip used in this hub is the FE1.1s chip, a highly integrated 4-port hub controller that can be found through the usual Chinese resellers. This hub controller doesn’t require much, just a 12MHz crystal, a few passives, and four USB jacks.

Of particular interest is how [Nate] is connecting this hub to the Pi Zero. He’s left the option open for using either a USB cable, or soldering the USB’s differential pairs directly between the Pi and the hub. In either case, the hub should work, and with the addition of the zeners, fuses, and other parts that keep the hub from frying itself, [Nate] might have a very nice project on his hands.