The Fridge Hacking Guide By BrewPi

August 3, 2014 by Matt Terndrup 20 Comments

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The team behind BrewPi are at it again! This time they have created an online guide showing how to convert a min-fridge into a Raspberry Pi & Arduino controlled fermentation chamber. In it, they describe 3 possible options:

Option 1: Make a simple switched power cord, without hacking into the fridge electronics.
Option 2: Make a switched power cord, but also override or remove the thermostat.
Option 3: Rip out the thermostat and fully integrate the SSRs into your fridge (which is what [Koen] and [Elco] did).

First things first though. They had to clean the fridge. And depending on where they got it or how long it has been unplugged for, the inside might have been pretty rank and disgusting from mold growing out of every corner. This took a good hour or so to clean properly lest the brewing process get infected with external grossness. This is all worth it because a well-controlled fermentation chamber results in a superior batch of beer.

They put their laser cut case on top of the fridge, holding an LCD, Raspberry Pi, Arduino and the BrewPi Arduino shield. The Arduino reads the temperature sensors inside the fridge, the beer and the ambient temperature. Then it controls the SSRs they added to switch the compressor and a heater. Then, the cables were routed through the fridge and take control of the compressor.

Continue reading “The Fridge Hacking Guide By BrewPi” →

Raspi Ambilight Integrated In A 19″ Rack Packs Lots Of Peripherals

August 2, 2014 by Mathieu Stephan 6 Comments

Ambilight systems create light effects around your monitor that correspond to the video content you’re playing. [Sébastien] just build his (French translated to English, original here) and embedded all the elements in a 19 inch rack he bought from Farnell.

As most ambilight systems we’ve covered over the years the HDMI signal is first split in two, one being sent to his monitor while the other is converted into a S-Video signal. The latter is then captured with a STK1160 stick connected to a Raspberry Pi. A python script using the OpenCV library is in charge of extracting the frames pixels and figuring out what colors should be sent to the SPI connected LPD8806 LEDs. A nice web interface also allows to drive the LEDs from any platform connected to his local network. Finally, a standard HD44780 LCD and an infrared receiver are connected to the raspberry, allowing [Sébastien] to control and monitor his platform. Funny thing: he also had to use two relays to power cycle his HDMI splitter and converter as they often crash. You can check out a demonstration video from a previous revision after the break.

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A Real Raspberry Pi Clone (Not ‘Inspired By’)

July 30, 2014 by Brian Benchoff 63 Comments

odroid A few years ago, Broadcom had a pretty nice chip – the BCM2835 – that could do 1080 video, had fairly powerful graphics performance, run a *nix at a good click, and was fairly cheap. A Broadcom employee thought, “why don’t we build an educational computer with this” and the Raspberry Pi was born. Since then, Broadcom has kept that chip to themselves, funneling all of them into what has become a very vibrant platform for education, tinkering, and any other project that could use a small Linux board. Recently, Broadcom has started to sell the BCM2835 to anyone who has the cash and from the looks of it, real Raspberry Pi clones are starting to make their way into the marketplace.

Other Raspberry Pi clone boards out there like the Banana Pi and the HummingBoard don’t use the same BCM2835 found in the Raspi and the new Odroid. The new board also has the same 26 pin GPIO expansion socket, and runs the same binaries as the Raspberry P;. It is a clone in every sense, with a slightly different form factor geared towards very tiny, portable, and battery-powered use cases.

Unlike the official Raspberry Pi Compute Module, the Odroid isn’t meant to be used as a system on module, shoved into any product that needs a fast-ish ARM core without needing engineers to actually design a circuit with an ARM. The Odroid is a cut-down, extremely minimalist version of the Raspi, perfect for any project where space is at a premium.

There are a few interesting features included on the Odroid: there’s an on-board battery connector, a real-time clock on the board, and more of the BCM2835 GPIOs are exposed (although not the same ones as the upgraded RPi Model B+). There’s no Ethernet, but odds are if you’re building something that’s battery-powered, you won’t need that anyway.

As far as price goes, you can pick one of these Odroids up for $30 USD, with $9 shipping from South Korea. That’s pretty comparable to the price of a real Raspberry Pi, but if the features in the Odroid are worth it to you, it might be a worthwhile clone.

Hackaday Links: July 27, 2014

July 27, 2014 by Brian Benchoff 14 Comments

Taking apart printers to salvage their motors and rods is a common occurrence in hacker circles, but how about salvaging the electronics? A lot of printers come with WiFi modules, and these can be repurposed as USB WiFi dongles. Tools required? And old printer, 3.3 V regulator, and a USB cable. Couldn’t be simpler.

The Raspberry Pi has a connector for a webcam, and it’s a very good solution if you need a programmable IP webcam with GPIOs. How about four cameras?. This Indiegogo is for a four-port camera connector for the Raspi. Someone has a use for this, we’re sure.

The one flexible funding campaign that isn’t a scam. [Kyle] maintains most of the software defined radio stack for Arch Linux, and he’s looking for some funds to improve his work. Yes, it’s basically a ‘fund my life’ crowdfunding campaign, but you’re funding someone to work full-time on open source software.

Calibration tools for Delta 3D printers. It’s just a few tools that speed up calibration, made for MATLAB and Octave.

[Oona] is doing her usual, ‘lets look at everything radio’ thing again, and has a plan to map microwave relay links. If you’ve ever seen a dish or other highly directional antenna on top of a cell phone tower, you’ve seen this sort of thing before. [Oona] is planning on mapping them by flying a quadcopter around, extracting the video and GPS data, and figuring out where all the other microwave links are.

PowerPoint presentations for the Raspberry Pi and BeagleBone Black. Yes, PowerPoint presentations are the tool of the devil and the leading cause of death for astronauts*, but someone should find this useful.

* Yes, PowerPoint presentations are the leading cause of death for astronauts. The root cause of the Columbia disaster was organizational factors that neglected engineer’s requests to use DOD space assets to inspect the wing, after which they could have been rescued. These are organizational factors were, at least in part, caused by PowerPoint.

Challenger was the same story, and although PowerPoint didn’t exist in 1986, “bulletized thinking” in engineering reports was cited as a major factor in the disaster. If “bulletized thinking” doesn’t perfectly describe PowerPoint, I don’t know what does.

As far as PowerPoint being the leading cause of death for astronauts, 14 died on two shuttles, while a total of 30 astronauts died either in training or in flight.

ASTROGUN Is Like Asteroids On Steroids

July 27, 2014 by Rick Osgood 50 Comments

Astrogun

As the Jerusalem mini Makerfaire approached, [Avishay] had to come up with something to build. His final project is something he calls ASTROGUN. The ASTROGUN is a sort of augmented reality game that has the player attempting to blast quickly approaching asteroids before being hit.

It’s definitely reminiscent of the arcade classic, Asteroids. The primary difference is that the player has no space ship and does not move through space. Instead, the player has a first person view and can rotate 360 degrees and look up and down. The radar screen in the corner will give you a rough idea of where the asteroids are coming from. Then it’s up to you to actually locate them and blast them into oblivion before they destroy you.

The game is built around a Raspberry Pi computer. This acts as the brains of the operation. The Pi interfaces with an MPU-9150 inertial measurement unit (IMU). You commonly see IMU’s used in drones to help them keep their orientation. In this case, [Avishay] is using it to track the motion and orientation of the blaster. He claims nine degrees of freedom with this setup.

The Pi generates the graphics and sends the output to a small, high-brightness LCD screen. The screen is mounted perpendicular to the player’s view so the screen is facing “up”. There is a small piece of beam splitting glass mounted above the display at approximately a 45 degree angle. This is a special kind of glass that is partially reflective and partially translucent. The result is that the player sees the real-world background coming through the glass, with the digital graphics overlaid on top of that. It’s similar to some heads-up display technologies.

All of the electronics fit either inside or mounted around a toy gun. The display system was attached with a custom-made fiberglass mount. The code appears to be available via Github. Be sure to watch the video of the system in action below. Continue reading “ASTROGUN Is Like Asteroids On Steroids” →

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.

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Hey There Little Plant. Let’s Be Friends!

July 22, 2014 by Matt Terndrup 12 Comments

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Perhaps, you’re circle of friends is getting too small. Or maybe, you just want to communicate with the leafy, green beings that have rooted themselves in the soil inside your house. If so, this environmental monitoring system will be perfect for you!

Created by [Dickson], this project monitors soil moisture, air temperature, and air humidity of your indoor plants and will alert you via email and SMS when your plants are thirsty. No longer will your sprouts shrivel up in the sun, but rather, they will be well-hydrated ready to produce their veggie goodness.

The system is battery operated, wireless, Arduino and Raspberry Pi based and comes with an Android app, which in turn allows you to view real-time and historical data, thus giving you the option to check in on your crew of Chlorophyll-embedded friends.