WebSockets, Raspis, And GPIO

February 7, 2013 by Brian Benchoff 6 Comments

socket

A while back, [Blaise] tried his hand at getting the WebSocket protocol working with PIC microcontrollers, WiFi adapters, and a few pots, knobs, and switches. It was an excellent project for its time, but now [Blaise] has a Raspberry Pi, and the associated GPIO pins and Ethernet connection. He decided it was time to upgrade his build to the Pi, this time with a project he calls PiIO.

The basic idea of [Blaise]’s project requires a Pi, a server, and a computer running a browser for the end user. On the Pi side of the build, [Blaise] connected a Microchip MCP3008 eight input, 10-bit ADC via the SPI bus. The Pi takes the ADC sensor values from pots, buttons, or any other analog source and sends them to a server with the WebSocket protocol.

The server hosts a web site written with Django, Autobahn, and Python to communicate with the Pi and host the web page for the data received from the Pi. There’s support for multiple Pis in [Blaise]’s build, making complicated projects we can’t even conceive very possible.

[Blaise] put up an awesome demo video of PiIO up; you can check that out after the break.

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PCB Production Workshop Means Everyone Gets An Arduino

February 7, 2013 by Brian Benchoff 3 Comments

nano

Over at the LVL1 hackerspace in Lousiville, [Brad] is putting together a workshop on etching PCBs at home. [Brad] wanted all the participants to take home something cool, so he settled on an Arduino clone as the workshop’s project.

The clone [Brad] used is the Nanino, a single-sided board we’ve seen before. Unfortunately, there aren’t any CAD files for the Nanino and doing a toner transfer with the existing PDFs was a pain. This led [Brad] to redraw the Nanino in Diptrace and put the files up for everyone to grab.

In his workshop, [Brad] is going to be using a laser printer, hydrogen peroxide, and HCl. one of the most common setups for home etching. If you’re in the Louisville area, you can make your own Nanino with a home etching workshop on March 16th. Be careful, though: those LVL1 guys are pretty weird; they have a moat and are building a homicidal AI.

Quantifying Cloudiness With OpenCV

February 7, 2013 by Eric Evenchick 12 Comments

The Shard is the tallest building in Western Europe, and has a great view of London. The condos in the building are very expensive, and a tourist ride to the top of the building costs £24.95.

Since the value of the view is so high, [Willem] wanted to quantify the quality of the view at any given time. His solution is the Shard Rain Cam. This device combines a Logitech webcam with a Raspberry Pi to capture a time-lapse set of images. These images are fed to a Python script using OpenCV which quantifies the cloudiness.

[Willem] also had to build a weatherproof enclosure with a transparent window for the camera and RPi. ‘Clingfilm’, which is British for saran wrap, and mineral oil is used to improve the waterproofing of an IP54 rated enclosure.

The resulting data is displayed on www.whatcaniseefromtheshard.com, which provides an indication of whether or not the view is worth £24.95. All of the Python code is available, and is a good starting point for learning about image processing with OpenCV.

Midwest RepRap Festival

February 7, 2013 by Mike Szczys 10 Comments

midwest-reprap-meetup

Midwesterner’s should take note — here’s an event that’s happening somewhere other than New York or California! We jest, of course there are great events in the Midwestern states every year, like the Kanasas City or Detroit Maker Faires. This event puts focus on 3D printing. The Midwest RepRap Festival will be held in Elkhart, Indian March 15-17, 2013. Despite the name, the event is meant to encompass all things involved with any brand, make, or variety of 3D printing.

The owners of a local business called The Royal Phoenix have opened their doors for the weekend. Organizers have arranged for [Josef Prusa] and [Johnny R] to speak. There will also be build events (one session will show the build process of the MendelMax 2.0) so feel free to bring your own equipment for help with construction or getting it dialed in.

There is no registration fee, or tickets. But it would be best if you did fill out the questionnaire so they have some semblance of how many people might be coming.

Heating, Bending, And Gluing To Make Acrylic Enclosures

February 7, 2013 by Mike Szczys 17 Comments

acrylic-enclosures-heating-bending-gluing

You can do a lot with acrylic and few tools. If you’re just starting out we’d suggest taking a look at [Michael Colombo’s] guide to heating, bending, and gluing to create custom acrylic enclosures. Chances are you already have most of what you need. The one tool you might be lacking is a heat gun.

The process starts with math. Before cutting the acrylic down to size you need to calculate how much you need. Next [Michael] demonstrates his cutting technique using a Dremel and a cut-off wheel. We prefer to clamp along the cut line, score many times with a razor knife, and snap the stuff. But you can also send it through a table saw if you have the right blade.

The bending technique he uses starts by clamping boards on either side of the bend. The acrylic left sticking out is pushed with a scrap board while the bend is heated with the heat gun. Once all of the corners were made in one piece the sides were glued in place. This last step can be tricky. The acrylic glue is made to work with perfect seams, so make sure your cuts are clean and the bent pieces line up.

The process was documented in the clip found after the jump. If you’re looking for a more targeted heat source check out this dedicated acrylic bender.

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Gifsockets: WebSockets Using Animated GIF Files

February 7, 2013 by Mike Szczys 15 Comments

gifsockets

Using animated GIF images as a crude WebSocket is an idea we’ve never come across before, but it actually makes a lot of sense. Not in terms of it’s overall usefulness, but just for the fact that the animated files work in a similar way. The nature of these animated containers is what makes it work. A GIF doesn’t tell the browser how many frames to expect, so the connection is kept open until the “hey this is the last frame” command is received. This can be used to stream data to anything that can play the animations.

The demonstration after the break shows this in action. Hello World and a couple of other test messages are pushed to the browser without refreshing the page. In our mind that’s what’s useful — real time updates without a refresh or any underlying client-side code structure. But we haven’t looked into the particulars like does this eat bandwidth even when nothing new is being sent?

When [Hans] wrote into us about this gif hack he referenced this discussion panel on WebSockets. We didn’t watch the whole thing yet, but apparently someone calls the gif trick the WebSocket of the ’90s.

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Pocket Serial Host Acts As An Apple II Disk Drive

February 6, 2013 by Mike Szczys 21 Comments

apple-II-pocket-serial-host

[Osgeld] is showing off what he calls a sanity check. It’s the first non-breadboard version of his Pocket Serial Host. He’s been working on the project as a way to simplify getting programs onto the Apple II he has on his “retro bench”. When plugged in, the computer sees it as a disk drive.

The storage is provided by an SD card which is hidden on the underside of that protoboard. This makes it dead simple to hack away at your programs using a modern computer, then transfer them over to the retro hardware. The components used (starting at the far side of the board) are a DB9 serial connector next to a level converter to make it talk to the ATmega328 chip being pointed at with a tool. The chip below that is a level converter to get the microcontroller talking to the RTC chip seen to the right. The battery keeps that clock running when there’s no power from the 5V and 3.3V regulators mounted in the upper right.

The video after the break shows off this prototype, the breadboard circuit, and a demonstration with the Apple II.

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