Day: October 8, 2010

Beefy Battery Backup Still Running After A Decade

October 8, 2010 by 39 Comments

In 1997 [Michael Butkus Jr.] found an uninterruptible power supply in the dumpster. The batteries were shot, but he needed a backup to keep his pellet stove running for heat, drive the exhaust fan to keep the smoke out of the house, and power his computer and other electronics. After a bit of head scratching he decided to beef up the UPS using deep-cycle batteries.

He actually built two of these. One is smaller, and similar to what we’ve seen before. The other is larger and uses four batteries, two pairs in parallel which are then connected in series. He’s careful to use heavy gauge wiring and 50 amp fuses for each battery, both of which will protect against the risk of fire. One thing we found interesting is that the batteries are stored in the basement, directly below the UPS which is connected via a short run of 12 gauge home electrical wire.

We were happy to see that he’s done updates at the top of his post over the years. He lost a few batteries due to neglectfully letting the water levels drop too much. He did switch over to sealed automotive batteries sometime in 2004 or 2005. Looks like things have been going strong ever since.

[Thanks Spencer]

Reddit Hacking For Votes And Profit

October 8, 2010 by 36 Comments

Looks like someone figured out how to game the Reddit system. This probably has been done before, but as far as we know nobody’s actually shared the methods in detail. [Esrun] wrote some scripts that allow him to register multiple accounts and use them to up-vote stories.

The hack goes something like this. A script registers a group of accounts. Each uses a different IP and the only part that requires intervention is typing in the Captcha. This doesn’t take long. You can see the script interface above as well as a demonstration video after the break.

Once the accounts have been acquired a story is submitted and the new accounts vote on it. They’re not all up-votes though, as having both up and down votes puts the article into the controversial section of Reddit (which is desirable), and doesn’t rouse as much suspicion from the moderators. He ran a few tests that he shares and it seems that as long as the article is interesting, this can be quite successful.

Great, more spam with our social media please.

Continue reading “Reddit Hacking For Votes And Profit” →

Add Supercaps To Your Exercise Routine

October 8, 2010 by 26 Comments

Many exercise machines generate electricity as you pedal or climb in order to run the on-board electronics. Unfortunately if you stop or even slow down too much the juice will die and your exercise program will reset. Wanting to improve on this gotcha, [Mike] cracked open his exercise bike and added some super capacitors.

On the circuit board he found an ATmega128 was in charge of the user interface. He probed the board a little bit and couldn’t find how it was connected to the power regulators. After some additional snooping he found it has its own SOIC regulator separate from the ones that run the display and peripherals. He takes us through the calculations he made before choosing his parts. What he ended up with is a set of three supercaps in series that add about two minutes of juice before the levels drop and the chip resets. The design of the board helped a lot as the high-load electronics (like the LCD screen) are on a separate power bus than the processor.

Game Boy Printer USB Cable And Software

October 8, 2010 by 19 Comments

[Furrtek] hooked up his Game Boy printer for use with a PC (translated). The two-part hack started with a cable to attach the device via USB. A Nokia interface cable was used as a base to translate the USB signals into serial, and an ATtiny45 microcontroller added to talk to the printer. He did a great job of free-forming the circuit alterations and fitting it back into the plastic USB plug housing.The next step was to write some software. Using VB6 he coded an application that loads in an image, scales it to fit, and allows you to adjust the contrast that the thermal printer produces. For testing purposes he’s reusing old receipts. See it in action after the break.

Continue reading “Game Boy Printer USB Cable And Software” →

Bench Supply With Current Limiting

October 8, 2010 by 14 Comments

This is a bench power supply with adjustable voltage and current limiting. [Sylvain’s] creation can regulate 0-25 volts while sourcing 0-5 amps. Current limiting is a nice feature as it will allow you to test your prototypes to ensure the power regulator you choose will not be over or underpowered.

This supply is really a two-in-one. The case has two separate circuits so that you can have different power rails going at the same time. There is a microcontroller involved, but the ATmega32 doesn’t do anything more than measure the voltage and amperage and drive the graphic LCD screen. Two potentiometers are responsible for setting the voltage and limiting the current.

[Thanks Sargonout]

Turtles All The Way Down, 40 Propeller MCU Skyscraper

October 8, 2010 by 29 Comments

Why bother interconnecting 40 Propeller microcontrollers one on top of the other? For the power that comes from parallel processing of course! [Humanoido] put the setup together for a total of 1280 ports, 640 counters, and more all running at 6.4 billion instructions per second for the low low price of 300-500$ by our count. The “skyscraper” even comes complete with software and schematics, promising developers the ability to expand or adapt for any venture. Why would we need such a setup in the first place? For any of the following: vision tracking/modification, artificial intelligence, advanced robotic control, or more.

Related: [Humanoido] loves putting MCUs together, check out one of his other creations the Basic Stamp supercomputer.

[Thanks Logan996]