Hardware Store Goods And An Mbed Combine Help Solar Panels Track The Sun

July 21, 2013 by 23 Comments

sun-tracking-solar-panels

If you have the space, and can build a tracking rig cheaply you’ll be able to get a lot more out of your solar panels. That’s because they work best when the sun’s rays are hitting them perpendicular to the surface and not at an angle. [Michael Davis] hit both of those stipulations with this mbed powered solar tracker.

At a garage sale he picked up an antenna motor for just $15. The thing was very old, but still wrapped in the original plastic. It’s beefy enough to move his panels, but he first needed a way to mount everything. After checking his angles he built a base out of wood and used galvanized water pipe as an axle. Cable clamps mate his aluminum angle bracket frame to the pipe. This frame holds the panels securely.

To track the sun he used two smaller cells which aren’t easy to pick out in this image. They are monitored by the mbed microcontroller which measures their output in order to point the assembly in the direction which has the most intense light. A couple of limit switches are included to stop the assembly when it reaches either side.

This technique of using small solar cells as the tracking sensors seems to work well. Here’s another project that took that approach.

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How The Mazes Were Generated For Classic Berzerk Game

July 21, 2013 by 16 Comments

berzerk-random-maze

This is a screenshot from the Atari 5200 version of the classic game Berserk. But the write-up we’re featuring actually looks at the original coin-op version. The maze for each level was established on the fly using a seed number fed into a rudimentary algorithm . Here’s a close look at how the maze building code actually worked.

Recently we saw a talk by Pitfall creator [David Crane] as part of our Retrotechtacular series. That is a real gem of programming history, and one of our favorite take-aways was that the levels were not hardcoded, but built using a random number generator algorithm with a hardcoded seed (so that the game was the same each time you played it). This uses a similar method but with a somewhat random seed.

The maze building was reverse engineered by observing the game in a MAME emulator, and by digging through disassembled code. Each time the code is “cold started” the seed starts out at zero, but from there the room number is used as the next seed. This is fed through a very simple algorithm. It generates directions for the walls, which use s few bit-wise operations to add the pillars inside the rooms.

It’s a great thing to study if you’re writing games for your embedded projects. By generating the room programmatically you don’t use up as much program memory. Of course these days even simple hobby controllers have way more storage to work with than [Alan McNeil] had when he designed Berserk.

[via Reddit]

[Image Source]

Quadruple Backflip And Sticks The Landing

July 21, 2013 by 24 Comments

This must have been a coding nightmare, and let’s not even mention the particulars of the mechanical build. The blurred ball near the center of this image is a robot doing a quadruple backflip before sticking the landing.

To the right is a high bar supported by a wood column and some guy-wires. At the beginning of the video below [Hinamitetu] hangs the robot from the bar where it starts its performance without any real motion. The servo motors whine as it gets ready; quickly getting up to speed with full revolutions around the bar. Oh how we wish there was more background info on the hardware! But we’re perfectly happy making our way through [Hinamitetu’s] video collection, which include other gymnastics disciplines like the floor routine. He even posted his own blooper reel that shows the high bar isn’t always a rosy experience.

If you’re thirsting for more amazing performances you won’t be disappointed by this high wire act.

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Well That’s Finally Over With

July 20, 2013 by 150 Comments

HaD

When the owner of the site wanted to sell Hackaday you guys wanted a Kickstarter to crowdfund the purchase and keep it in the community. I obliged and started a crowdfunding campaign. All things must pass, and I got an email from the owner, [Jason]:

Looks like a nice showing but we won’t hit even 100k
I guess we tried…. I have two solid offers from really cool folks. Will keep you posted.

Yes, that’s right, we’re finally done with the crowdfunding campaign. The end time for the campaign is now set for Monday at noon – you can’t actually delete Indiegogo campaigns – and I’m very, very doubtful it will be funded by then.

I have two words for those who supported Hackaday and this crowdfunding campaign: thank you. It’s astonishing we raised what we did without the infrastructure, licensed business, and non-profit status that would make Hackaday really cool. You guys believe in the future of Hackaday, and I’m very thankful for that.

As for the people who vomited vitriol against me in the comments of the crowdfunding announcement, I also have two words for you.

Even though the dream of a Hackaday owned by the community is dead now, I’m extremely confident we’ll find a better home for Hackaday that will allow us to keep moving forward and allow us to do some really cool things we’ve been thinking about for a while. I’ve spoken with a few of the possible future owners, and let me assure you they’re cool people. No, we won’t be doing grants for builds, but I assure you Hackaday will come out of this better than how it went in.

TL;DR: We didn’t quite get to the best of all possible universes, but things are going to be better than how they were before. Everything’s cool, don’t freak out. We’ll tell you stuff when we know more.

Arduino Cellphone

July 20, 2013 by 27 Comments

OLYMPUS DIGITAL CAMERA

The fact that you can build a cellphone around an Arduino is pretty neat. But we’re drawn to this project more as a testament to the advancement of hobby electronics. An [Average Joe] can build this thing with a minimum or background knowledge and without breaking the bank. Wow.

Of course this isn’t the first DIY cellphone we’ve come across. One of our favorites is this one which resides on a home etched PCB. There was even another Arduino offering with similar components back in September. But the one seen above really pulls it all together into a package that is usable for everyday life. The components include and Arduino Uno, GPRS shield from Seeed Studios, a TFT touch screen, Lithium battery and charging circuit, and a few other bobbles. All of it is mounted inside of a 3D printed case.

A simple phone calls for a simple UI and that’s included as well. The main menu has two buttons, one for placing a call, the other for sending a text. From there you get the virtual keypad seen above for typing out the phone number or composing a message.

[Thanks Victorzie]

Reverse Engineer A PSU To Change Its Output Voltage

July 20, 2013 by 33 Comments

reverse-engineering-psu

[Semicolo] has a bunch of old PSUs on hand which he pulled out of some Lexmark dot matrix printers. In their stock form they put out 40V, which is close to the 35V max he needs to run the stepper motors on a 3D printer he’s been building. So he reverse engineered the PSU to change its output.

On the left you can see the top of the PCB. [Semicolo] flipped it over and snapped a picture of the traces on the bottom of the board. With a bit of work in The Gimp (FOSS image editing software) he was able to convert the traces to black and white. Overlaying the picture of the top with a 50% transparency of the traces made it rather easy see the connections and generate a schematic for the hardware. That’s a really cool trick!

Figuring out how it’s supposed to work is a big step in achieving his goal. The next step was to see if he could bend the circuit to his will. He had previously run across ATX PSU hacks which changed the reference voltage in order to alter the output. He grabbed a datasheet for the HA17431 variable shunt regulator. It lays out how to tune the output based on values of a few external components. He dropped in one resistor and the output measured 31V, well within his target range.

LED Module Used To Display Load, Traffic, And Status Data For Your PC

July 20, 2013 by 7 Comments

cpu-monitoring-block

You’re going to like [Ivan’s] write-up for this LED computer status monitor. Of course he didn’t just show-and-tell the final product — if he had you’d be reading this in a Links post. But he also didn’t just detail how he put the thing together. Nope, he shared pictures and details of every iteration that got him here.

It started off with a tachometer. Yeah, that analog display you put on the dashboard of your car which reads out RPM. He wanted to make it into a USB device which would read out his CPU load. But that’s an awful lot of work when it can only display one thing at a time. So he decided to add an 8×8 LED module which would display the load for each individual core of his CPU. It looks great next to the illuminated tachometer. From there he added resolution by transitioning to an RGB module, which ended up sucking him into a coding project to extend the data pushed to his embedded hardware. In the end his ReCoMonB (Real Computer Monitoring Block) displays CPU load, RAM usage, several aspects of HDD activity, as well as the network up and down traffic.

We think he’s probably squeezed all that he can from this little display. Time to upgrade to a TFT LCD.

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