Adding GPIOs To The Raspberry Pi With The Camera Interface

July 24, 2014 by Brian Benchoff 9 Comments

GPIOs

The Raspberry Pi Model B+ was just released, and now everyone who picks one of those up has a few more GPIO pins to play around with. For the millions of people with the two-year-old version of the Pi, we’re still stuck with the same old, same old: 17 GPIOs on the big header, and that’s about it as far as toggling pins goes.

The Broadcom SoC on the Pi has far more GPIO pins than are broken out on the large header, and a few of those go to the CSI camera interface. These GPIOs can be broken out with a few flat cables (Portuguese, Google Translatrix), giving you four more GPIOs, and this technique can also be used with the new, expanded Model B+.

The CSI camera connector has two I²C lines that go directly to the camera, controllable in Linux as GPIO0 and GPIO1. There are two more GPIO connectors on the CSI connector controllable as GPIO5 and GPIO21. By carefully slicing and soldering wires to a flat cable, these GPIO lines can be broken out onto a breadboard.

There’s a video below demonstrating these GPIO lines being used to control a few LEDs. Of course, anything that is possible with a normal Raspi GPIO is possible with the CSI connector GPIO lines.

Continue reading “Adding GPIOs To The Raspberry Pi With The Camera Interface” →

THP Hacker Bio: Kenji Larsen

July 24, 2014 by Brian Benchoff 12 Comments

thp-hacker-bio-kenji-larsen

I met up with [Kenji Larsen] at HOPE X last weekend, and I’m fairly certain he was the coolest person at a conference full of really cool people. Talking to him for a little bit, you get a sense of what it would be like to speak with [Buckmister Fuller], [Tesla], or any of the other ‘underappreciated, but not by people in the know’ minds scattered about history. I’ll just let his answers to our hacker bio questions demonstrate that.

7033431402348237268 [Kenji]’s project for The Hackaday Prize is the Reactron Overdrive. It’s not just one board he’s building here, but an entire suite of sensors, interfaces, and nodes that form a complete human to machines – note the plural ‘machines’ – interface. When you consider that no one knows what the Internet of Things actually is, and that [Kenji] is working on IoT 3.0, you get a sense that there’s really something here. Also, his project log has a Tron Recognizer in it. That has to count for something, right?

Interview/Bio below.

Continue reading “THP Hacker Bio: Kenji Larsen” →

20,000 Hackers

July 24, 2014 by Mike Szczys 15 Comments

What a pleasant thing to wake up and realize that we now have more than 20,000 Hackers on Hackaday.io. It wasn’t even two months ago that we celebrated passing the 10k mark. While we’re talking numbers, how about 2,075 projects, and 148 hackerspaces?

But what’s in a number? It’s what this stands for that really gets us excited! You took the leap and decided to show off what you’re working on while you’re still working on it. This is the key to pollinating ideas. One concept can result in many awesome spin-off projects. So if you haven’t yet written about that killer idea bouncing around in your head, do it now and be the inspiration for the next iteration of amazing hacks.

Much more to come

Our crew has been refining an overhaul of how the feed works to make it easier to know when and how your favorite hackers are updating their builds. You should see that functionality live in August. We’re also working on improving interactivity so that you can better find others with similar interests whether it’s just for casual conversation or to undertake an epic build as a team.

We’re certainly not above pointing out our own weaknesses. The Stack never took off. The idea seemed like a good one, but we need your help figuring out how to make it shine. Leave a comment below telling us what you think The Stack should be and how you think it should work.

A Lesson In Blind Reverse Engineering – Signals Intelligence

July 24, 2014 by Will Sweatman 20 Comments

spread sheet of binary data

In a fit of desperation, I turned to data mining tools and algorithms, but stepped back from the horror of that unspeakable knowledge before my mind was shattered. That way madness lies.

–[Rory O’hare]

Wise words. Wise words, indeed. Who among us hasn’t sat staring into the abyss of seemingly endless data without the slightest clue to what it means or even how to go about figuring out what it means? To literally feel the brain damage seeping in as you start to see ‘ones’ and ‘zeros’ reach out to you from every day electronic devices…like some ghost in the wires. But do not fear, wise hacker! For we have good news to report! [Rory O’hare] has dived into this very abyss, and has emerged successful.

While others were out and about playing games and doing whatever non-hackers do to entertain themselves, [Rory O’hare] decided to reach out and grab some random wireless signals for a little fun and excitement. And what he found was not just a strong, repeating signal at 433Mhz. Not just a signal that oozed with evidence of ASK. What he found was a challenge…a mystery that was begging to be solved. A way to test his skill set. Could he reverse engineer a signal by just looking at the signal alone? Read on, and find out.

Fantastic Tach Is Strangely Called Tachtastic

July 24, 2014 by Rich Bremer 8 Comments

We all have projects from yesteryear that we wish had been documented better. [EjaadTech] is fighting back by creating a project page about a tachometer he built 3 years ago while in college. He’s done a great write-up documenting all the steps from bread-boarding to testing to finished project. All of the code necessary for this tachometer is available too, just in case you’d like to make one yourself.

At the heart of the project is an AVR ATMega8 chip that performs the calculations and controls the LCD output screen that displays both the immediate RPM as well as the average. To hold everything together, [EjaadTech] etched his own custom PCB board that we must say looks pretty good. In addition to holding all the necessary components, there is also an ISP connector for programming and re-programming.

There are two attachment options for sensing the RPM. One is a beam-break style where the IR emitter is on one side of the object and the receiver is on the other. This type of sensor would work well with something like a fan, where the blades would break the IR beam as they passed by. Then other attachment has the IR emitter and receiver on one board mounted next to each other. The emitter continually sends out a signal and the receiver counts how often it sees a reflection. This works for rotating objects such as shafts where there would not be a regular break in the IR beam. For this reflective-based setup to work there would have to be a small piece of reflective tape on the shaft providing a once-per-revolution reflection point. Notice the use of female headers to block any stray IR beams from causing an inaccurate reading… simple and effective.

Zero-Dollar AC System Looks Funny But Works Well

July 24, 2014 by Rich Bremer 119 Comments

Summer is here and with summer comes hot days. You probably know that us humans get uncomfortable if the temperature rises too much. Sure, we could turn on the loud and inefficient window AC unit and try to stay mildly comfortable while the electric company pick-pockets pennies from our change purse, but what is the fun in that? [Fran] had a better idea.

He noticed that his basement was always in the upper 50°F range regardless of how hot it was outside. He wanted the cool basement air to reside upstairs in the living area. After thinking long and hard about it he decided that a box fan and two long, skinny cardboard boxes assembled together would be enough to move the required amount of air. Both the fan and boxes were kicking around the house so was no cost and no risk to try this out. Continue reading “Zero-Dollar AC System Looks Funny But Works Well” →

Fishing For Radio Signals With The Moxon Antenna

July 23, 2014 by Adam Fabio 4 Comments

mox-antenna

[Bill Meara] has finished his latest project, a Moxon antenna for HF on 17 meters. [Bill] is well-known here on Hackaday. When not building awesome radios, he can be found ranting about ham radio. His new antenna turned out to be a true hack. He even used a hacksaw to build it!

The Moxon antenna is named for the late [Les Moxon, G6XN] who first described it in “Two-Element Driven Arrays”, a QST magazine article published in July of 1952. [Bill] built his Moxon loosely based on [Jim/AE6AC’s] excellent instructions. The design is incredibly simple – a two element directional antenna using crappie fishing poles as spreaders. That’s crappie as in the fish, not the quality of the pole. Crappie poles are typically made up of telescoping sections of graphite or fiberglass in common lengths of 14, 16, and 20 feet. The poles can be bought for under $20 at sporting goods stores. [Bill] used 16 foot poles purchased from Amazon.

The antenna is created by connecting all four poles at their bases in an X shape. The wire elements are stretched across the ends of the poles. The entire antenna bends up as the stiff poles hold the driven and reflector elements in tension. [Bill] used some scrap wood and U-bolts to attach the fishing poles, and bungee cord ends at the tips. Since the antenna is directional, [Bill] added a TV antenna rotor to spin the beam around. The antenna is so light that one could get by with a couple of cords and the “Armstrong method” of antenna rotation.

Once up on the roof, [Bill] found his antenna really performed. He was easily able to cross the Atlantic from his Northern Virginia home to France, Belgium, and Latvia. The mostly horizontal antenna makes it a bit more unobtrusive than other directional designs. [Bill] mentions that his neighbors haven’t revolted yet, so he’s continuing to enjoy the fruits of his antenna labors.