This Toy Intercom System Is Way Better Than A Pair Of Tin Cans And Some String

December 6, 2011 by Mike Nathan 36 Comments

toy-intercom-system

On his blog, [Kenneth Finnegan] recently showed off a replica of a fun toy he used to play with as a kid, a telephone intercom system. The setup is pretty simple, requiring little more than a pair of analog phones, a battery, and a resistor.

The phones are connected to one another using a standard telephone cable, but [Kenneth] uses a 9v battery to introduce a small bias current into the loop, allowing the speakers at either end to hear one another. He also added a small LED into the circuit so that there is a visual indication as to when both handsets are off hook.

The setup is very simple at the moment, though [Kenneth] does have some ideas in mind to enhance his intercom system. He hopes to tweak the remote phone to ring when the local phone is picked up, among other things.

Telephone technology is nothing new, but for just a few dollars (or less) your kids can be entertained for hours as [Kenneth] was way back when.

Continue reading to see a short video overview of the phone system, and be sure to share your ideas for enhancing it in the comments section.

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A Keyboard For Your FIGnition

December 4, 2011 by Brian Benchoff 13 Comments

[Carl] sent in his keyboard he made for his FIGnition microcomputer. At least now he has more than 8 buttons.

The FIGnition is a tiny little microcomputer that harkens back to the 8-bit days of yore. Designed to be an educational computer like the Altair or Heathkit (sans blinkenlights), the FIGnition gives its students ‘bare metal’ access to everything in the system. It’s powered by an ATMega168, a 4 Kb SRAM and an 8Mb Flash chip for storage. Unfortunately, the FIGnition only has 8 buttons to program Forth with, so [Carl]’s project is very much desired in the community.

To expand 8 buttons into an alpha-numeric keyboard, [Carl] came up with the solution of using two tact switches per character. The switches are of different button heights, so pressing a pair of buttons actuates the two buttons in order, which is natively interpreted by the FIGnition. It’s a perfect match for the chord-keys of the FIGnition.

Check out the video of [Carl]’s bundle of wires after the break.

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Reverse Engineering A Korg Monotribe

December 3, 2011 by Brian Benchoff 19 Comments

Yesterday, Korg released a firmware update to their ribbon controller synth, the Monotribe. The firmware is just an audio file that needs to be played to the sync input of the box. [gravitronic] thought this was rather interesting, so he decided to decode the monotribe firmware. It’s the first step to custom Monotribe firmware, and on the path towards reverse engineering this neat box.

After converting the firmware update to a .wav, [gravitronic] looked at the file with a hex editor and found that each sample is two bytes, and the left and right channels are the same. That made enough sense, so after getting rid of one channel, he sent it through Python to take a look at the patterns of ones and zeros.

Of course, [gravitronic] arbitrarily chose high = 1, low = 0, and little-endianness. The first result didn’t produce a nice “KORG SYSTEM FILE” in the header, so he tried other combinations until the output file looked reasonable. The result is the actual .bin file that’s going to serve as the basis for a nice homebrew firmware. You can grab [gravitronic]’s Python script here and decode your own firmware.

Building A Computer Around A 6502 Processor

November 30, 2011 by Mike Szczys 24 Comments

When it came time to try out some old-school computing [Quinn Dunki] grabbed a 6502 processor and got to work. For those that are unfamiliar, this is the first chip that was both powerful, affordable, and available to the hobby computing market back in the 1970’s. They were used in Apple computers, Commodore 64, and a slew of other hardware.

The first order of business in making something with the chip is to establish a clock signal. She sourced a crystal oscillator which runs at 1 MHz, but also wanted the option to single step through code. Her solution was to build two clock signals in one. A toggle switch allows her to choose the crystal, or a 555 timer circuit which uses a push button to fire each clock pulse.

Check out the video after the break to see some single stepping action. There’s no memory on board just yet. But the input pins have been hard-wired to voltage or ground to simulate data input. We wondered what she was up to with that HEX Out project which stiffs the logic on the data bus. Looks like it’s extremely useful in this project!

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Earthquake Detector Could Have Helped During Quakepocalypse

November 27, 2011 by Brian Benchoff 13 Comments

[Andrea] built a seismic wave detector that warns of a possible impending earthquake. Because P waves travel much faster than the “make everything shake” S waves, building a device that detects P waves serves as an early warning system that alerts building occupants to go under a door frame. [Andrea]’s build detects these fast-moving P waves and only took an hour to make.

Last August, those of us on the east coast of the US had to live through Quakepocalypse, a magnitude 5.9 earthquake centered around Middle of Nowhere, Virginia. For those of us who have decided to stay, rebuild, and put our garden chairs upright again (so brave…), [Andrea]’s build could have been very useful.

The mechanics of the build is very simple: a pair of springs and levers are electrically wired together so that whenever there’s a sudden shock, a buzzer goes off. It’s very similar to an ancient Chinese earthquake detector that detects P waves by dropping a ball into a frog’s mouth.

While we’re not sure if a few of [Andrea]’s devices would be needed to detect P waves coming in off-axis, the build is simple enough to build dozens of them. Check out the video of the build in action ~~after the break~~ here.

Zero-G Experiments Will Make Some Pretty Pictures

November 16, 2011 by Brian Benchoff 4 Comments

Does a yo-yo work in zero-g? How about a paper airplane? These questions were answered in 1985 on the Space Shuttle Discovery, but reproduction of results is the cornerstone of the scientific method. [Rob] is about to reproduce some of the awesome zero-g pictures by riding on a vomit comet and taking a few pictures of water globes colliding.

For the last few months, [Rob] has had a standby ticket on the G-Force One, a plane that takes passengers on parabolic arcs to simulate microgravity. He was lucky as his standby ticket allowed him to take a few experiments on board, so [Rob] decided there’s just not enough awesome pictures of water colliding in zero-g.

He built a rig out of micro t-slot aluminum. A DSLR is mounted to the frame along with a few ‘test tubes’ containing water. When [Rob] blows through a tube, a small sphere of water will be released to collide with other object. Think of it as the nerd’s version of water splash photography.

Of course, a trip through zero-g wouldn’t be complete without a few more experiments. [Rob] plans on testing a few toys to see if yo-yos ‘sleep’ without gravity (they don’t), and if a grandfather clock works on the moon (there’s a month-long day, so kind of). We can’t wait to see [Rob]’s pictures once he comes back to Earth.

Halloween Hacks: A Jacob’s Lantern Sure To Win The Carving Contest

November 3, 2011 by Mike Nathan 15 Comments

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jacobs-ladder-pumpkin

[Matt] entered himself in a pumpkin carving contest this year, even despite the fact that his artistic skills were a bit…lacking. He knew that he had very little chance of winning the contest unless he had a great gimmick to make his creation stand out, so he started brainstorming.

[Matt] figured that since his design would have to be somewhat simple, he needed something eye catching that he could add to the pumpkin after it went under the knife. Like a bolt of lightning, inspiration struck, and he set off to fetch an ignition transformer along with some wire coat hanger.

He built a makeshift Jacob’s ladder that would fit perfectly inside his hollowed out pumpkin, and proceeded to carve the pumpkin with the “Caution, risk of electric shock” logo, familiar to most anyone that works with electronics. You can see the final result in the video below, which we think looks pretty neat. If he didn’t end up winning the contest, we’d be shocked!

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