Two-Axis Solar Tracker

Solar panels are an amazing piece of engineering, but without exactly the right conditions they can be pretty fickle. One of the most important conditions is that the panel be pointed at the sun, and precise aiming of the panel can be done with a solar tracker. Solar trackers can improve the energy harvesting ability of a solar panel by a substantial margin, and now [Jay] has a two-axis tracker that is also portable.

The core of the project is a Raspberry Pi, chosen after [Jay] found that an Arduino didn’t have enough memory for all of the functionality that he wanted. The Pi and the motor control electronics were stuffed into a Pelican case for weatherproofing. The actual solar tracking is done entirely in software, only requiring a latitude and longitude in order to know where the sun is. This is much easier (and cheaper) than relying on GPS or an optical system for information about the location of the sun.

Be sure to check out the video below of the solar tracker in action. Even without the panel (or the sun, for that matter) the tracker is able to precisely locate the panel for maximum energy efficiency. And, if you’d like to get even MORE power from your solar panel, you should check out a maximum power point tracking system as well.

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Raspberry Pi Halt and Catch… Well, Halt

As far back as we can remember, there have always been hacks, exploits, and just curiosity about undocumented CPU instructions. The Z80 had them. Even the HP41C calculator had some undocumented codes. The HCF (Halt and Catch Fire) instruction was apocryphal, but we always heard the old video controller chips could be coaxed into blowing up certain monitors. You don’t hear too much about things like that lately, perhaps because fewer people are working in assembly language.

[Sergi Àlvarez i Capilla] not only works in assembly language, he was writing an ARM assembler when he noticed something funny. Instructions are built in a regular pattern and some of the patterns were missing. What to do? [Sergi] lost no time trying them out.

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Follow Me: Making Servos Track Hand Motion with Leap

The Leap controller is one of those gadgets that is probably better for its cool factor rather than its practicality. The time of flight optical sensor reads gestures, but it is hardly a substitute for a mouse in many cases. It seems like the best uses for it we’ve seen are dedicated systems that need to know where your hands are. [Justin Platz] and [Kurt Clothier], for example, have an interesting demo that uses a Leap to control a Raspberry Pi. The Pi commands servo motors that move LED blocks to track your hand motion. Their code is available on GitHub.

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Hackaday Prize Entry: Twitter Goes To The Dogs With Raspberry Pi Hack

Dogs are remarkable creatures. Anybody who has lived with one will know that they are very vocal beasts, with barks that range from noting the presence of a squirrel in the yard to the warning whine that says “I am about to pee on your shoes if you don’t take me outside.” [Henry Conklin] decided to computerize the analysis of these noises, putting his dog [Oliver Twitch] on Twitter so he could hear what he was saying while he was at work. [Henry] that is: [Oliver] stays at home.

He did this using a Raspberry Pi, which is set to record sound above a certain volume. With the system sitting by [Oliver’s] favorite window, this records his barks. The recordings are then analyzed using PyAudioAnalysis, a library that analyzes sounds, compares them to reference ones and classifies them.  The Raspberry Pi then posts the results onto twitter using Python-twitter.

The setup used by [Oliver] to capture the barks: a USB microphone, Raspberry Pi and WiFi USB dongle.
The setup used by [Oliver] to capture the barks: a USB microphone, Raspberry Pi and WiFi USB dongle.
Or rather, it will when [Henry] fixes a few bugs: right now it just posts a random string that is based on the length of the bark, not the type. [Henry] says he is working on the dog translation at the moment. It’s still a neat project that shows you how simple it is to use a few small bits of code to gather info from your environment and share these over the Internet. [Henry] also says that the next step is creating a weekly podcast for [Oliver]. I, for one, will be subscribing to hear his thoughts on how annoying the postman is, and how vexing it is to see a squirrel and not be able to chase them.

The 2015 Hackaday Prize is sponsored by:

Easy to Read Bicycle Computer

[David Schneider] had trouble seeing his bike computer in the sunlight and wanted a navigation solution that would be both readable and not require a smart phone. In good hacker fashion, [David] married a Raspberry Pi and a Kindle Touch (the kind with the E-ink display). The Kindle provides a large and easy-to-read display.

[David] was worried about violating the DCMA by modifying the Kindle. Turns out, he didn’t have to. He simply used the book reader’s Web browser and set the Pi up as a wireless access point. One clever wrinkle: Apparently, the Kindle tries to phone home to Amazon when it connects to a wireless network. If it can’t find Amazon, it assumes there’s no valid network and treats the network as invalid. To solve this issue, [David] causes the Pi to spoof the Kindle into thinking it gets a valid response from Amazon.

The other work around was to change how the Python application on the Pi updates the screen. [David] found that without that optimization, the constant redrawing on the E-ink display was annoying. The Pi-related hardware includes a GPS, some reed switches, and a WiFi dongle.

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Commodore C16 Resurrection with a Raspberry Pi

[lactobacillusprime] had a non-working Commodore C16 and too many Raspberry Pi computers, so he decided to bring the C16 back to life by emulating it on the Pi. At the heart of the project is the Pi, along with a small board that converts the old style Commodore keyboards (and joysticks) to a USB port.

Once you have the keyboard as a USB port, the rest of the project is more or less mechanics and software. [lactobacillusprime] did a nice job of getting everything in the new case, along with all the I/O wires routed through the existing ports. For software, Emulation Station does the job of launching the Commodore emulation on the Pi.

Of course, there’s no reason to limit yourself to just the Commodore emulator. Emulation Station along with the right back end emulators will allow this machine to play games that no real Commodore C16 could.

Of course, we were happiest to see him boot up Commodore 64 BASIC. Perhaps we should complete all those half finished C64 BASIC projects we started back in the 1980’s. In general, we hate to see old computers gutted instead of repaired, but at least this one will continue running its software. If you are upset about seeing a machine gutted,  you can always switch over to our previous coverage of putting Commodore guts in a new box.

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Raspberry Pi and Windows 10 IoT Core: A Huge Letdown

Last Spring, Microsoft unveiled their plan for Windows and the Internet of Things. It starts with the Raspberry Pi and Windows 10 IoT Core – a stripped down system with Windows API calls running on an ARM architecture. Yes, Microsoft is finally moving away from the desktop, building a platform for a billion Internet of Things things, or filling the gap left by tens of thousands of POS terminals and ATMs running XP being taken offline. Either one is accurate.

Earlier this week, Microsoft announced the first public release of Windows 10 IoT Core. This is the review, but here’s the takeaway: run. Run as fast as you can away from Windows IoT. It’s not worth your time unless you have a burning desire to write apps for Windows, and even then you could do a better job with less effort with any Linux distro.

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