Friday, March 7, 2014 - 01:01We’re Hiring
The title says it all. We need more writers to keep the fresh hacks coming, now’s your chance to apply for the job.
Contributors are hired as private contractors and paid for each post. Writers should have the technical expertise to understand the projects they are writing about, and a passion for the wide range of topics we feature. If you’re interested, please email our jobs line and include:
- Details about your background (education, employment, etc.) that make you a valuable addition to the team
- Links to your blog/project posts/etc. which have been published on the Internet
- One example post written in the voice of Hack a Day. Include a banner image, 150 words, the link to the project, and any in-links to related and relevant Hack a Day features.
Words of encouragement
First off, we won’t be discussing compensation publicly. Want to know what we pay? Send in a successful application and we’ll talk about it.
Secondly, don’t pass up this opportunity. I watched one of these posts go by and waited another year before I saw the next one and applied. Now I’m running the place. Our team is made up of avid readers. If you’re passionate about the stuff here and you have a few hours each week to do some writing you need to apply now!
Why are we hiring more writers?
You may have noticed that we’re starting to send people to events, and continuing our push to develop our own unique original content. Both of these take time and we need more team members to fill in the publishing schedule so that the Hackaday community gets the posts that it deserves.
So what are you waiting for? Ladies and Gentlemen, start your applications!
Filed under: Featured
Thursday, March 6, 2014 - 22:00The Mystery Of Zombie RAM
[Josh] had a little project where he needed to keep a variable in RAM while a microcontroller was disconnected from a power source. Yes, the EEPROM on board would be able to store a variable without power, but that means writing to the EEPROM a lot, killing the lifetime of the chip. He found an ATTiny can keep the RAM alive for a variable amount of time – somewhere between 150ms and 10 minutes. Wanting to understand this variability, he decided to solve the mystery of the zombie RAM.
The first experiment involved writing a little bit of code for an ATTiny4313 that looked for a value in RAM on power up and light up a LED if it saw the right value. The test circuit consisted of a simple switch connected to the power pin. Initial tests were astonishing; the ATTiny could hold a value in RAM for up to 10 minutes without power.
With the experiment a success, [Josh] updated his project to use this new EEPROM-saving technique. Only this time, it didn’t work. The value hidden away in RAM would die in a matter of milliseconds, not minutes. After tearing his hair out looking for something different, [Josh] rigged up an Arduino based test circuit with humidity and temperature sensors to see if that had any effect. It didn’t, and the zombie RAM was still not-undead.
The key insight into how the RAM in an ATtiny could stay alive for so long came when [Josh] noticed his test circuit had a LED, but the actual project didn’t. Apparently this LED was functioning as a very tiny solar cell, generating a tiny bit of current that kept the RAM alive. A dark room with a flashlight confirmed this hypothesis, and once [Josh] gets his uCurrent from Kickstarter he’ll know exactly how much current this LED is supplying.
Thursday, March 6, 2014 - 19:01Fail of the Week: WS2811 Pixel Failure on FLED
This Fail of the Week project comes from one of Hackaday’s own. [Ben] took on the FLED data visualization project as a way to make the SupplyFrame decor a lot more fun. He had quite a bit of help soldering the 96 WS2811 pixels into their custom made 6′x4′ enclosure and the results are really awesome. In addition to showing server load and playing games, FLED has become something of a job interview. Sit the prospective employee down at a terminal and give them an hour to code the most interesting visualization they are capable of.
But two weeks ago [Ben] staggered into the office and found the display was dead. Did he try turning it off and back on again? Yes, but to no avail. The power supply wasn’t the issue and there was no option but to pull the display off the wall and crack it open for a look at all those pixels. Since every one of them had 4 solder joints on either side he figured the problem was with a broken connection. But not so. He resorted to a binary search for the offending pixel by cutting the strand in half, and testing each portion. He tracked it down to the pixel whose underside was blackened as you can see above.
[Ben] thinks one of the capacitors inside the sealed enclosure blew, but isn’t certain. Feel free to tell us what you think failed in this component. But the thing we’d really like to know is if there is a more clever way to sniff out the offensive pixel without cutting the connections? Four hours on the floor with this thing (and no knee-pads) and [Ben] has sworn off sourcing pixels from random Chinese suppliers. He might go with pre-assembled strings next time. We chuckle; this is the high-tech equivalent of trying to get old strands of Christmas lights to work.
If you haven’t seen FLED in action, check it out after the break. It amazing how LED intensity and quality diffuser material can make a perfect grid of LEDs seem to dance in waves and color curves.
Fail of the Week is a Hackaday column which runs every Wednesday. Help keep the fun rolling by writing about your past failures and sending us a link to the story – or sending in links to fail write ups you find in your Internet travels.
Thursday, March 6, 2014 - 16:01TI Launches “Connected LaunchPad”
TI’s LaunchPad boards have a history of being both low cost and fully featured. There’s a board for each of TI’s major processor lines, and all of them support the same “BoosterPack” interface for additional functionality. Today, TI has announced a new LaunchPad based on their new Tiva C ARM processors, which is designed for connectivity.
The Tiva C Series Connected LaunchPad is based on the TM4C129x processor family. These provide an ethernet MAC and PHY on chip, so the only external parts required are magnetics and a jack. This makes the Connected LaunchPad an easy way to hop onto ethernet and build designs that require internet connections.
This development board is focused on the “Internet of Things,” which it seems like every silicon manufacturer is focusing on nowadays. However, the real news here is a low cost board with tons of connectivity, including ethernet, two CANs, 8 UARTs, 10 I2Cs, and 4 QSPIs. This is enough IO to allow for two BoosterPack connectors that are fully independent.
For the launch, TI has partnered with Exosite to provide easy access to the LaunchPad from the internet. A pre-loaded demo application will allow you to toggle LEDs, read button states, and measure temperature over the internet using Exosite. Unlike some past LaunchPads, this one is designed for easy breadboarding, with all MCU pins broken out to a breadboard compatible header.
Finally, the price is very right. The board will be release at $19.99 USD. This is less than half the price of other ethernet-ready development boards out there. This makes it an attractive solution for hackers who want to put a device on a wired network, or need a gateway between various devices and a network.
Thursday, March 6, 2014 - 13:00The Flaming Yinlips
No, that’s not a Playstation Vita up there, it’s a “Yinlips YDPG18A” portable game system. [Ian] found that his Yinlips was lacking in the flash memory department, so he fired up his soldering iron. The Yinlips is based on an Allwinner Sunxi series processor, and uses a standard TSOP48 footprint flash. There is some standardization in flash pin out and packages, so [Ian] picked up the largest pin compatible chips he could find – a pair of 256 gigabit (32 gigabyte) chips from Micron. Desoldering the existing flash proved to be a bit of an adventure as the flash was glued down. [Ian] also didn’t have his hot air gun handy, making things even more interesting. Careful work with a razor blade broke the glue bond.
It turns out that the soldering was the easy part. All flash chips have geometry, die count, page size, block count, sector size, etc. The geometry is similar to the geometry in a hard drive. In fact, just like in modern hard drives, a system will read some basic information before accessing the full storage array. In the case of NAND flash, the processor can access the first page of memory, and query the flash for its part number. Once the part number is known, the geometry can be determined via a lookup table. [Ian] checked the NAND table on github, so he knew going in that his flash chips were not supported. Due to the complexities of booting Allwinner processors into Linux or Android, the table and the NAND driver that uses it exist in several places. The bootloader’s axf file, U-Boot, and several flash application binaries sent from the PC based LiveSuit flash app all required modification. Most of these files were packed into a single flash image. [Ian] used imgrepacker to unpack the image, then opened the hex files. The fact that he knew what the original flash parameter tables looked like was key. He searched for an existing Micron flash table entry, and replaced the parameters with those of his new chips.
With all the files modified, [Ian] re-packed his flash image and sent it over. The Yinlips rewarded his hard work by continually resetting in a bootloop. [Ian] wasn’t going to give up though. He wired into the boot console, and discovered that a CRC check failure on one of his modified files was causing the reset. He then disassembled binary issuing the reset. Changing the return value of the CRC to always pass fixed the issue. [Ian's] now has a collagen infused Yinlips with 58GB of internal storage. Pretty good for a device that only started with 2GB.
Filed under: Android Hacks
Thursday, March 6, 2014 - 10:00Make a Plastic Bender using Stuff You Already Have
The team over at [2PrintBeta] found they needed some unique plastic profiles for their 3D printer the Printupy. Unable to find a supplier with what they needed, they decided to try building their own inexpensive bending station, using stuff they already had.
Not too concerned with the longevity of the system (or perhaps the flammability?) they’ve taken a wooden board and routed a straight groove through the center of it. Using a power supply and some Nichrome wire — it’s done.
They admit it’s really not the most durable and that it requires constant supervision in case of flames — but it cost next to nothing to make, and actually works quite well! What we like about the following video is they also show us the design process, the laser cutting, and bending to create the final product.
A simple way to upgrade this unit is to add a metal U-channel in the groove to reduce the fire hazard — like this acrylic bender we featured last year!
Filed under: how-to
Thursday, March 6, 2014 - 07:00Here’s the Dirt on Printing With Pollution
[Anirudh] and his friends were sitting around reminiscing about India. In particular, they recalled riding around in auto-rickshaws in stifling heat, watching their skin turn black from the exhaust. They started thinking about all of the soot and pollution in crowded cities the world over and wondered whether the stuff could be re-purposed for something like printer ink. That’s how they came up with their soot/pollution printer.
They created a soot-catching pump which they demonstrate with a burning candle. The pump mixes the soot particles with rubbing alcohol and an oil substrate and sends the ink to an HP C6602 inkjet cartridge. They used [Nicolas C Lewis]‘s print head driver shield for Arduino to interface with the cartridge, turning it into a 96dpi printing head that uses only five pins.
[Anirudh] and his friends plan to design a carbon separator using charged plates to capture the soot particles from pollution sources and filter out dust. Be sure to check out their demonstration video after the jump.
Thursday, March 6, 2014 - 04:00From Wireless Soundbar to Portable Boombox
[Frank] had wanted a portable Bluetooth boombox for a while, but when he did some price comparisons he found that they are pretty expensive. He decided to take matters into his own hands and modify two products he already had – into what he wanted.
The guts of his Frankenstein-boombox come from a Toshiba 3D Soundbar — a great product, but not as durable or portable as he needed. He then took an old mini guitar amp and started hacking the two together.
The soundbar features 4 speakers and a sub woofer — plus the amp and wireless capabilities of course — so [Frank] opted to just use the case of the guitar amp with the soundbar’s innards. He took some measurements and then built up a wooden support for the speakers inside the amp. He’s also sealed off the tweeters sound cavity from the main SUB to keep the sound nice and clear.
In addition to the Bluetooth control — the unit also comes with a remote. Can you spot his cleverly hidden IR sensor?
What we also like about this project is his colorful narrative as he explains his process — it kind of reminds us of [Arduinoversusevil's] video on his Accurate-ish Pneumatic Cylinder Positioning. You can just tell he had an absolute blast hacking this together.
For another unorthodox Bluetooth boombox — have you seen this potato cannon?
Filed under: digital audio hacks
Thursday, March 6, 2014 - 01:01Hackaday Scouts For Hacks at SXSW
It seems like everyone is going to South by Southwest this year. We even heard about it on The Today Show this week. But we still have hope that there’s awesomeness to be found. A few of our crew will be there this year and they’re on the lookout for something special. The festival starts on Friday and runs more than a week to the following Sunday but our guys will be on the ground Sunday, March 9th through Tuesday the 11th.
Sure, we’ll take a gander at the interactive hardware areas, but preliminary research tells us these may be watered down to the lowest common denominator. What we really want to see is if a Burning-Man-like culture is beginning to coalesce around SXSW. Are you carrying around your own hacked hardware at this year’s event? Do you roll up in a custom party-mobile and spend the week trying to keep the 24-hour tailgate alive with your fold out pig roaster and awning-based entertainment system? We’d like to check that out.
[Eren], [Alek], and [Ivan] are handling coverage of the event. They’ve been killing themselves making Hackaday Projects an awesome place to share and interact. What they wanted was a bit of down time, but handing out T-shirts and Stickers in exchange for a look at your hacks doesn’t get in the way of that. Connect with them on Twitter using the hash tag #HaD_SXSW. They’ll be using it to tweet their activities but of course it works both ways. Your best bet of just crashing into these guys is to check out [Alek's] talk on StageTwo.
[Background Image Source]
Filed under: news
Wednesday, March 5, 2014 - 22:00Bench Power Supply Constant Current EZ-SET
Here is a nice hack you may find very useful if you have a cheaper bench power supply that supports constant current limit protection (CC mode) and the only way to set or check your max current limit is to disconnect your circuit, short the power supply outputs and then check or set your limit. Yes, what a pain! [Ian Johnson] was enduring this pain with a couple of Circuit Specialist bench power supplies and decided to do something about it. After finding a download of the circuit diagram for his CSI3003X-5 supply he was able to reverse engineer a hack that lets you press a new button and dial-in the max current setting. Your first guess is that he simply added a momentary button to short the power supply outputs, but you would be wrong. [Ian’s] solution does not require you to remove the load, plus the load can continue running while you set your current limit. He does this by switching the current display readout from using 0–3 volts off an output shunt resistor to using the 0-3 volts output from a digital potentiometer which is normally used to set the power supplies’ constant current limit anyway. So simple it’s baffling why the designers didn’t include this feature.
Granted this is a simple modification anybody can implement, however [Ian] still wasn’t happy. A comment by [Gerry Sweeney] set him on the path to eliminate the tedious multi-button pressing by implementing a 555 momentary signal to switch the circuit from current load readout to current set readout. This 2nd mod means you just start pressing your up-down CC set buttons and it momentarily switches over the display to read your chosen max current and a few moments later the display switches back to reading actual load current. Brilliant! Just like the expensive big boy toys.
[Ian] doesn’t stop with a simple one-off hack job either. He designed up a proper PCB with cabling and connectors, making an easy to install kit that’s almost a plug-in conversion kit for Circuit Specialist bench power supplies (CSI3003X-5, CSI3005X5, CSI3003X3, CSI3005XIII). It is not a 100% plug-in kit because you do have to solder 3 wires to existing circuit points for signal and ground, but the video covering that task seemed trivial.
This hack could very well work with many other power supplies on the market being Circuit Specialist is just rebadging these units. For now, only the models listed after the break are known to work with this hack. If you find others please list in the comments.
After the break we will link to all three progressive mod videos incase you want to learn how to mod your own power supply or you could just order a prebuilt kit from [Ian].
Adding off-load constant current setting.
Replacing the front panel push-button switch with a 555 chip & relay
New pcb for the CC modification.
Single variable output 0-30VDC 0-3A Bench Power Supply #CSI3003X-5
Single variable output 0-30VDC 0-5A Bench Power Supply #CSI3005X5
Dual variable output 0-30VDC 0-3A Bench Power Supply #CSI3003X3
Dual variable output 0-30VDC 0-5A Bench Power Supply #CSI3005XIII
Wednesday, March 5, 2014 - 19:00Hackaday 68k: Blinking An LED
Time for another update for the Hackaday 68k, the 16-bit retrocomputer developed on Hackaday to show off both our love for vintage hardware and our new project hosting site. There’s still invites to be had, people. Get ‘em while they’re hot.
This post is going to cover exactly how complex a simple 68000 system is. The answer is, “not very.” A simple 68k system is at least as simple to design than some other homebrew systems we’ve seen around here. Yes, a 16-bit data bus means there’s more wires going everywhere, but like she said, just because it’s bigger doesn’t mean it’s harder.
There is some progress to report on the construction of the Hackaday 68k. The processor has been verified as working with a blinking LED. It’s the ‘Hello World’ of computer design, and it’s at least as complex as blinking a LED with an Arduino.
You’re gonna want to click that ‘Read more’ link.
The Journal Of Simple 68000 Systems
At least half of the purpose for this project is to demonstrate the 68000 is well suited – simple, even – for a homebrew computer project. The homebrew systems that infrequently hit the Hackaday tip line are usually based around the 6502 CPU, or at the very least something in that family. Now, how do we compare a simple 6502 and 68000 system? How about describing a simple system with both chips?
Building a simple 6502 system
For a simple 6502 system, you’ll want the 6502 itself, some RAM, and an EEPROM. Let’s just say we’ll use a 62256 SRAM for the RAM, and a 28256 EEPROM for the ROM. Wire up the RAM starting at $0000 and make sure you have some of the EEPROM at $FFFF. A few NAND gates will do for the logic glue. Ground the A14 pin of the RAM, and you’ll have a basic system with 16k RAM, 32k ROM, and a lot of space to put in any peripherals.
Throw in a 6551 ACIA and you have a serial port. With a little bit of glue logic and a MAX232 chip, you can make a simple 6502 system that’ll run BASIC. Put a pin header on the 16 address and 8 data lines and you have an extensible system using seven chips:
- 6502 CPU
- 28256 EEPROM
- 62256 SRAM
- 6551 ACIA
- MAX232 serial thingy
- 74HC04 and 74HC00 logic ‘glue’
Wiring these up involves using the address lines for decoding, the R/W and Phi2 lines for memory control, and shoving a clock signal and reset circuit in there somewhere. You’ll need a crystal, some caps , a few resistors, and a reset button, but there you have it: a simple 6502 system. You can build this on a breadboard in a weekend. No. Big. Deal.
Building a simple 68000 system
“But the 68000 is so much more complex!”, you cry, “There’s more pins! Sixteen of them, and that’s just the data lines! What the hell is BGACK?” I’m not saying you’re wrong, but I do choose to ignore you. It’s actually very easy to construct a simple 68000 system, if you know what pins to ignore:
- /DTACK & /BERR
DTACK is a product of very small and slow memories available in the late 70s. The idea behind DTACK was to have the RAM (or ROM, or whatever) acknowledge it got the required data off the data bus. If the RAM (or whatever) didn’t put this pin low in time, the CPU would enter a ‘wait state’; basically the 68000 would just sit there until the RAM caught up.
Now, with fast, huge SRAMs and modern components, you don’t have to worry about this. Ground DTACK and you’ll be fine. Do your calculations for the timings, but you’ll be fine.
BERR is the Bus Error pin, telling the CPU something is wrong with a MMU, there’s a “non-responding device”, or something else sufficiently complex that it shouldn’t be included in a minimal system. Tie this pin to +5 V.
- Bus Arbitration Control; /BR, /BG, & /BGACK
These pins are for DMA. We’re doing a simple system here, so no DMA. Tie BGACK and BR to +5 V, and ignore BG. Done.
- Interrupt Control; /IPL0, /IPL1, & /IPL2
Interrupts? Again, we’re doing a simple system with some RAM, ROM, and a serial port. Tie these to +5.
- M6800 Peripheral Control; E, /VPA, & /VMA
The old Moto engineers that designed the 68000 were extremely cool and gave 68000 system designers a way to interface the old 6800-series parts – ACIAs, display processors, the RIOT, PIAs, floppy disk controllers – to the 68000. These pins are how you do it. Are we using any of these parts? No? Good. Tie /VPA to +5 and ignore /VMA and E.
- Processor Status Pins; FC0, FC1, & FC2
These pins tell the rest of the system if the CPU is currently in user or supervisor mode, the kind of stuff that would be handy for an MMU to have. Are we using an MMU? Then ignore these pins.
So, where does that leave us? We have 16 data pins, 23 address pins,, and a few others: We can tie Reset and Halt together. The asynchronous bus control pins, /AS, /UDS, /LDS, & R/W are all that’s needed to do a proper memory decoding and control.
How does that compare to a 6502? With the 8-bit chip, you’ll need to use the R/W pin to tell if you’re reading or writing, and the Phi2 pin on the 65xx is analogous to the /AS pin on the 68k. Really, if you design something with a 68000, the only real difference between it and an 8-bit chip are the /UDS, & /LDS pins, and they’re only there for accessing either D0-D7 or D8-D15.
A chip count for the 68000? You’ll need a CPU, two 8-bit RAM chips, two 8-bit EEPROMs, some sort of ACIA, and a bit of glue logic. You can do that in a dozen chips, max. It’s a lot more wires or traces between chips, but that’s neither here nor there.
So there you go. A reasonable case for the 68000 not being overly complex for a homebrew project.
Blinking A LED
The ‘Hello World’ of computer design is freerunning the processor. All this means is to get the CPU cycling around its address space with an instruction hardwired onto the data pins, attaching an LED to one of the higher address pins, and turning it on. The LED will blink depending on the clock speed and what pin the LED is wired up to. Here’s the video:
That’s the 68000 with the all the data pins tied to ground, the /AS, /UDS, /LDS, & R/W pins ignored, and a Maxim DS1813 reset chip to handle the power-on and push button reset. I’m running it with a 4MHz oscillator. Anyone care to guess what address pin that LED is tied to?
I would like to note that since the 68000 has 68,000 transistors, it’s still possible I’m using fewer transistors to blink a LED than I would with an Arduino. If anyone from Atmel has a more precise count for the number of transistors on an ATMega, drop a note in the comments.
Unfortunately there’s a rather large gulf between blinking an LED and the next, “look what I did!” post. There’s a lot of thought that goes into address decoding for the RAM, ROM, and peripherals, and a shocking amount of work that goes into wirewrapping these chips together. Here’s the current state of the RAM board:
That’s eight 512k x 8 SRAM chips, with the data and address lines all wired up. Blue is data, green is address. I’m not quite sure how long it took me to wrap all those pins, as I’m measuring the time in units of Deep Space Nine episodes. I can tell you that wirewrapping, DS9, and a six-pack is the closest I’ve come to bliss.
For the next post, I’m going to go over the address decoding and memory control logic for the RAM, ROM, whatever I’ll be using for a serial port, as well as the bus transceivers. Then I’ll actually have to wrap all these circuits up; not a quick job. A little code burned onto an EEPROM, and then I’ll actually have something to show off. It’ll be awesome.
Until then, you can check up on my progress on Hackaday Projects.
Filed under: Hackaday Columns
Wednesday, March 5, 2014 - 16:01A Low Cost Arduino FPGA Shield
[technolomaniac] is kicking butt over at Hackaday Projects. He’s creating a low cost Arduino based FPGA shield. We’ve seen this pairing before, but never with a bill of materials in the $25 to $30 range. [technolomaniac's] FPGA of choice is a Xilinx Spartan 6. He’s also including SDRAM, as well as an SPI Flash for configuration. Even though the Spartan 6 LX9 is a relatively small FPGA, it can pack enough punch that the Arduino almost becomes a peripheral. The main interconnect between the two will be the Arduino’s ability to program the Spartan via SPI. Thanks to the shared I/O pins though, the sky is the limit for parallel workflow.
[technolomaniac] spent quite a bit of time on his decoupling schematic. Even on a relatively small FPGA power decoupling is a big issue, especially when high speed signals come into play. Thankfully Xilinx provides guides for this task. We have to mention the two excellent videos [technolomaniac] created to explain his design. Documenting a project doesn’t have to be hours of endless writing. Sometimes it’s just easier to run a screen capture utility and click record. As of this writing, the schematic has just been overhauled, and [technolomaniac] is looking for feedback before he enters the all important layout stage. The design is up on his github repository in Altium format. Due to its high cost, Altium isn’t our first pick for Open Hardware designs. There are free viewers available, but [technolomaniac] makes it simple by putting up his schematic in PDF format (PDF link). Why not head over to projects and help him out?
Filed under: Arduino Hacks
Wednesday, March 5, 2014 - 13:01Make Your Electronics Lab in a Box
Unless your lucky enough to have a big personal workshop where you can have dedicated stations for all kinds of different tools, you’re probably like most of us here at Hack a Day — lots of projects, but never enough space.
[McLovinGyver] lives in a small flat, and finds setup and cleanup time often take longer than the project itself — so he’s come up with this handy dandy Electronics-Lab-in-a-Box (trademark pending).
The guide is really more of a series of pictures of his process of building the portable lab, but he shows off some great ideas of things you might want to include in your own personal version of it. The first step is deciding what tools you need in the lab. In general, your power supply unit, soldering iron, hot air re-flow and fume exhaustion are going to dictate the general size and shape of your lab — from there, it’s just a matter of filling in the gaps with the rest of your small tools.
One of our favorite features of this portable workstation is his clever wire management system — he’s added a compartment to hold all his wire and solder — everything is fed through small openings, allowing for easy access to whatever you need — without fumbling with a spool!
So, are you going to build one? Let us know in the comments, and if you make a really nice one, don’t forget to send it in through the Tips Line!
Wednesday, March 5, 2014 - 10:01Monster 100W LED Flashlight for Under $10!
What would you do if you came across a 100W, 7500 lumen LED diode for under $10? Probably something like this.
It’s actually quite amazing how cheap LEDs are getting. [Julian Ilett] found this 2″ x 2″ LED on eBay for only £4.79 (<$10 USD). It’s rated for 32-34V with a current draw of 3000mA, which works out to about 100W. Its brightness? 7500 lumens. That’s brighter than most home theater setups.
At that price, [Julian] had to try playing with one. The problem with these higher power LEDs is that they typically need a rather expensive LED driver, due to the less common voltages they operate at — and of course, the concern of over-driving them and burning them out. Not interested in finding a suitable driver, [Julian] decided to try something a bit less conventional — wiring a pair of 18V drill batteries in series.
Unfortunately, fully charged drill batteries tend to hover around 20V, not 18V, which when doubled is quite a bit over the recommended voltage range for the LED. The good news is that since the LED draws so much current, there’s a good chance the voltage will drop right down to the “sweet spot” for the LED. So like any good hacker, [Julian] decides to throw caution to the wind and just try it.
As luck would have it, it worked! He darn near fried his camera sensor looking at it though! Satisfied with his test he’s gone on to make the world’s cheapest — and perhaps ugliest — 100W LED flashlight.
And upgraded it since.
And if you don’t need that much brightness, you could always recycle your lithium batteries into some awesome PVC flashlights!
[via Hacked Gadgets]
Wednesday, March 5, 2014 - 07:00Russian Man Builds a Chainsaw Out of a Grinder
What this (Russian?) man has done is modified his large electric grinder — into a chainsaw. He’s added a weld plate, some mounting locations, and now it can accept either grinding wheels, or after a few minutes of assembly, a full length chainsaw blade attachment. He’s probably pretty proud of himself, but we really hope he doesn’t end up losing a finger… or worse.
Anyway, we’re not even going to point out the lack of safety guarding in this video, because it is such an obvious bad idea in general. That being said, it actually works in the demonstration!
Stick around — don’t sweat too much though, no one gets hurt. There is one thing that can be said about this project though… It’s most definitely a hack.
For a slightly safer home power tool conversion, there’s always the Scrappy Lil’ Circular Saw.
Filed under: tool hacks
Wednesday, March 5, 2014 - 04:01DIY Bell For Your Trains of Lionel
[Peter]‘s dad recently rekindled his love for Lionel trains and wanted a bell to keep the crossings safe for O gauge drivers and pedestrians. Using parts he had lying around and a doorbell from the hardware store, [Peter] concocted this DIY train crossing bell at his dad’s request.
The idea was to make the bell chime about once per second. To achieve this, [Peter] used a non-repeating electro-mechanical doorbell that emits a single note on continuous press. You could also roll your own bell with a spring-loaded solenoid and something bell-like for it to strike.
[Peter]‘s three-stage design uses a full-wave bridge rectifier to convert the AC from the train transformer to DC. He drops it to 5V and sends it through a 555 and some resistors to set the frequency and duty cycle. His output section translates the voltage back up to match the input desired by the doorbell. [Peter] included a 1N4002 as a back EMF snubber to keep feedback from damaging the power MOSFET. Stick around for his demonstration video after the jump.
Filed under: toy hacks
Wednesday, March 5, 2014 - 01:01Interrupt Free V-USB
[Tim's] new version of Micronucleus, Micronucleus 2.0, improves upon V-USB by removing the need for interrupts. The original Micronucleus was a very small implementation of V-USB that took up only 2KB. Removing the need for interrupts is a big leap forward for V-USB.
For those of you that do not know, “V-USB is a software-only implementation of a low-speed USB device for Atmel’s AVR® microcontrollers, making it possible to build USB hardware with almost any AVR® microcontroller, not requiring any additional chip.” One tricky aspect of using V-USB is that the bootloader requires interrupts, which can lead to messy problems within the user program. By removing the need for interrupts, Micronucleus 2.0 reduces the complexity of the bootloader by removing the need to patch the interrupt vector for the user program.
With the added benefit of speeding up the V-USB data transmission, Micronucleus 2.0 is very exciting for those minimal embedded platforms based on V-USB. Go ahead and try out Micronucleus 2.0! Leave a comment and let us know what you think.
Filed under: Microcontrollers
Tuesday, March 4, 2014 - 22:01Public Transportation Display
[Adrian] and [Obelix] wanted to have an easy way to know when to expect the public transportation, so they hacked an LED dot matrix display to show arrival times for stops near their dorm.
They found the display on Ebay with a defective controller which they replaced with an ATmega328p. They connected the display to the internet by adding a small TP-Link MR3020 router and connecting it to the ATmega328p via a serial line. Their local transportation office’s web page is polled to gather wait times for the stops of interest. All rendering of the final image to display to the dot matrix display is done on their PC, which then gets pushed through to the MR3020, which in turn pushes it out to the ATmega328p for final display.
[Adrian] and [Obelix] warn about setting proper watchdog timers on the display driver to make sure bugs in the controller don’t fry the dot matrix elements. Their ATmega328p dot matrix driver code can be found on [Adrian]‘s GitHub page.
Check out a video of the display in action after the jump.
Tuesday, March 4, 2014 - 19:00Retrotechtacular: Lighting the Way for Talkie Pictures with Optical Sound Recording
This week’s Retrotechtacular is a 1943 Encyclopædia Britannica film focusing on optical sound reproduction for motion pictures. Both the sound and the images are recorded on film, which is only affected by light. Therefore, the sound waves must be converted to changes in light.
This is done the way you might expect: the sound waves hit a microphone and the changes in current are amplified and used to control the intensity of light falling on the film. Three types of soundtracks are described and wonderfully demonstrated at the end of the film.
All three types are made from a series of thin bars of light, and the corresponding current value is represented by changes in either their length or their width. In the Unilateral Variable Area recording, the bars extend from the right side of the sound track. Bilateral Variable Area recorded bars emanate uniformly toward the edges from the center. In Variable Density recording, all of the bars extend from the left to right extremes, but their thickness varies.
Variable Density recording is done with a light valve, which contains a pair of delicate metallic ribbons in a magnetic field that move like shutters when the sound current flows through them. The light coming through to the film is varied by the slot created in the space between the ribbons. The light patterns are changed back to sound through a photoelectric cell, which converts the variations in light back to changing current. These changes are amplified and run through a loudspeaker. Be sure to watch to the end to catch a demonstration of the recording methods, set to what we’re pretty sure is Camille Saint-Saëns’ Danse Macabre.
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.
Filed under: Retrotechtacular
Tuesday, March 4, 2014 - 16:00Woodhouse Controls Your House, Avoids Danger Zone
[Pat] may not be the world’s most dangerous secret agent, but he does have Woodhouse taking care of his home. [Pat] has been upgrading his sonic screwdriver home automation system these past few months. Waking up to a chilly room led him to start hacking a thermostat interface. [Pat] found that his furnace only needed one 24VAC wire to be shorted to a common during a call for heat. [Pat] was lucky in that his thermostat was low voltage. While researching a thermostat hack, we made the painful discovery that our thermostat is 120VAC, so watch for that if you try this one at home.
[Pat] connected his thermostat leads to a relay controlled by a Raspberry Pi. The Pi would read a temperature sensor and set the relay accordingly. That was fine for a quick hack, but opening an SSH window to change the temperature isn’t the most convenient thing in the world. Enter an old Asus Transformer Prime tablet. [Pat] coded up an Android Holo style interface using AJAX along with HTML/CSS/jQuery and PHP. OpenMic+ constantly listens for voice commands, and fires them off to Tasker tasks as needed. He calls the results Woodhouse, and the interface is very slick. The tablet controls and graphs temperature, [Pat's] media center, and his lights. Woodhouse is even [Pat's] right hand man when getting ready for those intimate moments. We can’t wait to see what [Pat] comes up with next.
Filed under: home hacks