Challenge: Figure Out How This Logic-based Chaser Works

January 25, 2012 by 37 Comments

[Andrea] built this LED chaser using one logic chip. It illuminates all but one of the six LEDs, with the dim bit moving back and forth along the row in a chase sequence. This is something like an inverse Larson Scanner without the fading tail. But doing it with a logic chip instead of a microcontroller is a fun challenge.

Which brings us to the point of this feature. [Andrea] didn’t really post an explanation of how the circuit works. Usually missing details mean that we archive the tip and move on to the next one, but we think this provides a fun activity. Can you figure out how the circuit works? We already know that it’s using a CD4017 decade counter/divider chip. This gets its clock signal from a 555 timer circuit. [Andrea’s] schematic is a bit hard to read, but grab a copy, blow it up a bit (or use your browser zoom) and study the CD4017 datasheet (PDF) if you need to.

Want proof that it does actually work? It’s embedded after the break.

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Custom Microcontroller Using Only A Dremel

January 25, 2012 by 35 Comments

Check out this 6-pin MSP430 microcontroller. What’s that you say? TI doesn’t make a 6-pin MSP430? True, Texas Instruments doesn’t make one, so [Greg] grabbed his Demel and a cutoff wheel, and chopped up a larger uC to arrive at this package.

It may sound a bit crazy at first, but when you think about it there’s nothing really all that special about this. The plastic package on DIP components these days is mostly empty. The silicon die which does the computing is quite small in comparison, and usually mounted in the very center of the part. [Greg] simply cut off eight of the unneeded pins (four from each end).

Well, it might be a stretch to call them unneeded since he cut the ground and voltage pins. He gets around this issue by taking advantage of the same properties of the I/O pins used in this barebones RFID tag. You can inject power through the I/O and we’d bet you could easily use this chopped-up MSP430G2211 as an RFID tag if you wanted to.

[Thanks Ian]

Bending A Printer Control Board To Output POV Messages

January 25, 2012 by 12 Comments

Confronted with the issue of finding a use for his mounting pile of junk electronics, [Rue] set out to build a persistence of vision device using a hardware state machine. We have a suspicion that his original link may go down if there’s too much traffic so here’s a cached link just in case.

Any board that is MSC-51 or MCS-48 based would have worked for his purposes. This is because the addressing scheme of the hardware makes it an easy hack. The image above shows him cutting off the processor from this board. It was chosen because of a 74HC373; it was a mistake at first but since it’s pin compatible with the 74HC374 that he needed a simple swap did the trick. From there a clock source was added, and the address information necessary to display the message was burned into an EEPROM.

Step twelve of his writeup shows a Morse Code message created by attaching the board to a broomstick and twirling it around in an arc. We took  just a minute to decode the message and believe it’s a shout-out to Hackaday. Nice, thanks for reading [Rue]!

Stop Light Converted To Control Office Foot Traffic

January 25, 2012 by 4 Comments

traffic-light

When [Paul Rea] started work with his current employer, he was intrigued by a traffic light that sat unused near the entrance of the “Engineering Loft” where he was stationed. He promised himself that he would get it working one day, but several years passed before he had the chance to take a closer look at it.

He took the light home with him over Thanksgiving weekend last year, and started to dig around inside to see how things were wired up. It turns out the light was a pretty simple contraption, though he discovered it ran on mains voltage, something [Paul] didn’t really want to fiddle with. He swapped out the traffic light’s bulbs for some low-voltage models, which he could easily power with a 12v wall wart.

[Paul] then added an Arduino and PIR sensor to the light fixture in order to detect when someone was leaving the Engineering Loft, warning those who are on their way in. He says that people don’t really pay attention to the light very much, though he is pretty happy with the results.

Continue reading to see a short video of the traffic light in action.

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Hide Your Repeater And Gain A Radio

January 24, 2012 by 41 Comments

[Bradley]’s workplace was recently put into a position where they needed to install a WIFI network to operate some wireless barcode scanners, which was left open for anyone to connect to. Management thought that the people in the shop, who didn’t really need internet, would get less work done if they had access to it. So they just simply stuck the access point as far away as they could. Problem with that theory is that the signal still reaches a little bit where they don’t want it, and people in the shop really want access, so a repeater is needed.

Of course this repeater cant be just sitting out in the open. so [Bradley] decided to hide the it inside of an old radio. Searching around he finally settled on a 10$ ebay radio from the 1980’s, which is large enough to hold the guts of a WRT54G. The routers AC adapter was popped open and wired into the AC input of the radio, the main board and antennas were epoxied to the back. Once everything is buttoned back up you’re left with a hidden repeater, and a fully functional radio.

Now hopefully none of his bosses read his blog!

The Phone Box

January 24, 2012 by 19 Comments

[Nerdindustries] had a interesting idea; “what if you could just flip a switch and call someone?”. This happens a lot, especially in companies where your trying to catch a certain someone who is always swamped in phone calls. The Phone Box is a basic Nokia cellphone that has a number stored into its speed dial. To help aid in communication the phones output is directed to a three and a half watt amplifier module ensuring that your going to hear it.

A delay circuit was made out of a basic RC network, so when you hit the switch the phone has a chance to power up and fully boot. Once the delay triggers it presses the speed dial button and off you go. Now someone has already asked “Why don‘t you just call them?”, and we got a kick out of the first answer “calling someone is NOT nerdy.”

Join us after the break for a quick video.

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Converting A Mill To CNC

January 24, 2012 by 16 Comments

For most of the past year, [Joel] has been working on converting a manual mill to a CNC mill with the addition of a computer, brackets and stepper motors. He’s put an amazing amount of effort into his project, and the result is awesome and much less expensive than buying and shipping an old Bridgeport mill.

The project started with this mill from Grizzly. It’s a step above the small ‘hobby mills,’ but still very affordable at $1200 shipped to [Joel]’s driveway. The work began by fabricating an enclosure for the PC and motor drivers out of an electrical panel box. The controller box includes a touch screen, keyboard and computer running Mach3 CNC software. The computer connects to a breakout board with a trio of motor drivers providing power for the stepper motors on each axis.

After a few months (good things take time), [Joel] was ready to attach the stepper motors to the axes of the mill. He’s just put up a few videos of milling copper-clad board for PCBs and surface machining ABS, viewable after the break. For a total investment that is less than finding, buying, and repairing an old industrial mill, we’ll call [Joel]’s project a success.

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