Make a simple O-scope with a FTDI board and a couple of ADC’s

[RandomTask] has posted a nice tutorial on how to use a FTDI serial to usb converter, and a couple analog to digital converters to make a simple software oscilloscope. Using a “Universal Serial to USB converter” and one of many FTDI break out boards, he first reprograms the chip using FTDI’s programming software to put the device into a FIFO (first in first out) mode.

From there a pair of ADC0820 8 bit digital to analog converters are wired up, and input is fed to a couple 555’s for testing. It should be noted that there is no input protection, so things like voltages above 5 volts, or negative voltages are a big no-no with this setup. It still could be very handy while working with micro controllers or other digital circuits.

Data is then sent to the computer and displayed using a program, which has some basic features like scale and triggering, but also contains a couple bonuses like Calc Freq and Calc V delta calculation.

Many people have these little serial to usb converters, and might be in need of a simple scope. If you’re one of them, then you can cobble this together pretty darn quickly, and cheaply.

Unshredding Paper

[Roel] had read that people won the DARPA shredder challenge, but that their technology was kept a secret, interested in this concept he also remembered an episode of the X-Files where they had reconstructed shredded paper using a computer system. Unlike most computer based TV show BS this did not seem to be too far fetched so he went about trying it himself.

First a note is written, and then cut up into strips, the strips are then scanned into a computer where the magic happens. Next each strip outlined in polygons and then the software is to follow the polygon outline looking for a change in color at the pixel level. The software then goes into a pattern matching mode and reassembles the paper based on a scoring system.

While not many people use old fashioned strip shredders anymore, the basic idea works and if you really wanted to expand it could be applied to cross cut or particle shredders.

Got Dead Bugs In Your Stereo?

It happens to the best of designers, spending untold amounts of time designing a complex device just to find out that you missed a trace, or you couldn’t rout something to something else. As time marches on its becoming a bit less common to pop open a commercially produced device and see a little jumper wire or 2 flying across a pcb, or a resistor straddling an IC.

But when [Ilektron] opened up a Yamaha Dolby Pro Logic receiver to scavenge for parts he saw a very big “oops” and a even wilder fix. The maker took a pair of relays, flipped them “belly up” and hot glued them into place on top of a pair of ICs. Then the mess was “dead bug” wired to the circuit using insulated and uninsulated bus wire, contacts were then reinforced / insulated using more hot glue.

This is one of the most hacky fix we have seen in a commercially produced product, but we would love to hear your amusing horror stories of “WTH did they do?” So join us in the comments after the break.

Programming AVR I2C Interface

I2C as many of you know, is a simple serial interface for many peripheral devices to micro controllers, but it can quickly become confusing to people who may not be accustom to it. Because of that, I2C tutorials are always welcome, and this new tutorial by [Embedds] does an excellent job of how to use I2C with an AVR with a 24C16 2Kbyte EEPROM.

The first half of the tutorial provides a clear explanation of how I2C works, including its signal structure, addressing, and data packets. It then moves on to AVR territory showing how to setup the I2C in an AtMega micro controller. The author uses a pretty standard to most of us Arduino, with software written in AVR C and a nifty little GUI programming application which eases the hassle of dealing with AVRDude directly.

Plenty of code samples follow from twiddling registers to a full blown application reading and writing bits from the EEPROM to a serial terminal on a PC.

Remove Function Lock Key with a 4016 and a 555

Many companies today try to simplify life by over complicating the keyboard. Microsoft has been doing it since 2001. If you love your ergonomic keyboard, but hate that “function lock” key, there are plenty of options out there for you to try.

The least complicated way is to either modify some XML or just set macros up in the MS software, but who wants to do that every time they re-install Windows? Reader [Elco] didn’t so he added a simple little 555 circuit inside the keyboard, that automatically re-enables the Flock after three seconds if he happens to hit it during fast and furious typing.

Now no matter what system the keyboard is plugged into he does not have to worry that if he hits F7 whether the system is going to spell check his document, or reply to an email, or that F2 is actually going to rename something and not undo his work silently.

Need a Hand Drying Those Gloves?

While being caught out in the rain skiing, [Andrew] was left with a pair of soaking wet gloves. Leaving them to air dry did little good, as after 3 days they were still wet, and blowing a fan at them did little to nothing to help the situation. Luckily [Andrew] had been thinking about ways to make a forced air glove drier for some time now using standard plumbing fittings.

A prototype was made similar to consumer models where the glove is fit over the end of a pipe, and while this worked great to dry the palms, it did not help the wet finger situation at all. In order to solve this issue a new design was whipped up featuring 4 fixed fingers and a movable thumb made out of copper pipe. A little drilling, and soldering was performed then the metal hand was then duct taped to the end of a hair drier, turning soaked gloves into perfectly dry ones in about three hours.

Self Balancing Robot with Wii parts

[Moser] is looking to build a quadrocopter sometime in the future, without plunking down a good chunk of change for a kit model. Looking for a good place to start he figured why not work on the control system. Thinking that the balance of the flying platform of doom would be similar to working out a self balancing robot he spent a couple days and made his self balancing robot.

Armed with a plan, and a logic analyzer, he went out and got a  Wii Motion Plus, which is an inexpensive three axis gyroscope, and a nunchuck which features an accelerometer which both can be found in just about any strip mall. After fiddling for a day getting the Wii nunchuck and motion plus to play nice all it took was a little more time to code up the self balancing routines.

And while its not perfect, all its going to take is a little tweaking and maybe some faster servo motors to get things up to top notch.

Join us after the break for a couple quick videos.

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