Fail Of The Week: Rewiring Robosapien

April 10, 2014 by 34 Comments

fotw-rewiring-robosapien

Our first thought was “check out all of those TO-92 components!”, but then we saw the wiring nightmare. [Tom] picked up a Robosapien from an estate sale for just $10. Most hackers couldn’t resist that opportunity, but the inexpensive acquisition led to a time-consuming repair odyssey. When something doesn’t work at all you crack it open to see what’s wrong. He was greeted with wiring whose insulation was flaking off.

This is no problem for anyone competent with a soldering iron. So [Tom] set to work clipping all the bad wire and replacing it with in-line splices. Voila, the little guy was dancing to his own tunes once again! But the success was short-lived as the next day the robot was unresponsive again. [Tom] plans to do some more work by completely replacing the wires as soon as he receives the replacement connectors he ordered. So what do you think, is this an issue that will be resolved with a wire-ectomy or might there be actual damage to the board itself?

2013-09-05-Hackaday-Fail-tips-tileFail 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.

Fake Audiophile Opamps Revealed

April 10, 2014 by 64 Comments

chip

The OPA627 is an old, popular, and very high-end opamp found in gear cherished by the most discerning audiophiles. This chip usually sells for at least $15, but when [Zeptobars] found a few of these expensive chips on ebay going for $2, his curiosity was piqued. Something just isn’t right here.

[Zeptobars] is well known for his decapsulating and high-resolution photography skills, so he cut the can off a real OPA627, and dissolved one of the improbably cheap ebay chips to reveal the die. Under the microscope, he found an amazing piece of engineering in the real chip – laser trimmed resistors, and even a nice bit of die art.

The ebay chip, if it were real, would look the same. It did not. The ebay chip only contained one laser trimmed resistor and looks to be a much simpler circuit. After a bit of research, [Zeptobars] found it was actually an AD774 opamp. The difference is small, but the AD774 still has much higher noise – something audiophiles could easily differentiate with their $300 oxygen-free volume knobs.

This isn’t the first instance of component counterfeiting [Zeptobars] has come across. He’s found fake FTDI chips before, and we’re counting the days until he gets around to putting a few obviously fake ebay 6581 SID chips under the microscope.

An Exceptional BASIC Computer

April 10, 2014 by 39 Comments

BASIC

Since [Dan] has started using microcontrollers, he’s been absolutely fascinated by the fact these chips are essentially low performance computers. Once he caught wind of TinyBASIC, he decided he would have a go at creating a simple, tiny computer that’s very simple to the old, tiny, 8-bit computers of yore.

The computer is built on an Arduino shield, using TinyBASIC, the TVout library, and the PS/2 keyboard library. After piecing together a little bit of code, the Arduino IDE alerted [Dan] to the fact the TVout and PS/2 libraries were incompatible with each other. This inspired [Dan] to use the ATMega328P as a coprocessor running the TVout library, and using the capacious ATMega1284P as the home of TinyBASIC and the PS/2 library.

A circuit was put together in Fritzing using minimal components, and a PCB milled out of copper board. After the board was tinned, [Dan] had a beautiful minimalist retro computer with nearly 14kB of RAM free and an RCA display.

Future versions of the build will probably be based around the Arduino Mega, allowing for a TV resolution of 720×480. Also on tap are an SD card slot, LEDs, pots, and possibly even headers for I2C and SPI.

Resetting DRM On 3D Printer Filament

April 10, 2014 by 94 Comments

The Da Vinci 3D printer is, without a doubt, the future of printing plastic objects at home. It’s small, looks good on a desk, is fairly cheap, and most importantly for printer manufacturers, uses chipped filament cartridges that can’t be refilled.

[Oliver] over at Voltivo was trying to test their new printer filament with a Da Vinci and ran head-on into this problem of chipped filament. Digging around inside the filament cartridge, he found a measly 300 grams of filament and a small PCB with a Microchip 11LC010 EEPROM. This one kilobyte EEPROM contains all the data about what’s in the filament cartridge, including the length of filament remaining.

After dumping the EEPROM with an Arduino and looking at the hex file, [Oliver] discovered the amount of filament remaining was held in a single two-byte value. Resetting this value to 0xFFFF restores the filament counter to its virgin state, allowing him to refill the filament. A good thing, too; the cartridge filament is about twice as expensive as what we would normally buy.

 

An Emulated Commodore 64 Operating System For The Raspberry Pi

April 9, 2014 by 39 Comments

Commodore-PI

 

It’s no secret that Commodore users love their old machines with the Commodore C64 being chief among them with 27 Million units sold worldwide. Speaking as a former Commodore Business Machines (CBM) engineer the real surprise for us is the ongoing interest and devotion to an era typified by lumbering 8 bit machines and a color palette consisting of 16 colors. Come to think about it, that’s the description of Minecraft!

Jump forward to today and it’s a generation later. We find that the number of working units is diminishing as age and the laws of entropy and physics take their toll.

Enter the Commodore Pi, an emulated Commodore 64 operating system for the Raspberry Pi. The goals of the project include an HDMI and composite compatible video output, SID based sound, Sprites and other notable Commodore features. They also plan to have hooks for more modern technology to include Ethernet, GPIO and expansion RAM.

A video demo of the emulator can be found below. If you’re just warming up to the Commodore world, you’ll definitely want to know the real story behind the C128.

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Turning An Analog Scope Into A Logic Analyzer

April 9, 2014 by 9 Comments

scope

When [Marco] was planning on a storage oscilloscope build, he realized having a small device to display eight digital signals on an analog scope would be extremely useful. This just happens to be the exact description of a simple logic analyzer and managed to turn his idea into a neat little project (German, Google translation).

The theory of operation for this surprisingly simple, and something that could be completed in a few hours with a reasonably well stocked hackerspace or parts drawer in a few hours. A clock generator and binary counter are fed into the lower three bits of a simple R2R DAC, while the 8 inputs are fed into an 8-input multiplexer and sent to the last bit of the DAC. With nothing connected to the logic analyzer inputs, the output to the scope would just be an 8-step ramp that would appear as eight horizontal lines on the screen. With something connected to the logic analyzer input, an extremely primitive but still very useful logic analyzer appears on the screen.

While it’s not the greatest analyzer, it is something that can be cobbled together in an hour or two, and the capabilities are more than sufficient to debug a few simple circuits or figure out some timings in a project.

Gaming On An 8x8x8 LED Cube

April 9, 2014 by 17 Comments

LEDCube

Building an LED cube is a great way to learn how to solder, while building something that looks awesome. Without any previous experience with soldering or coding, [Anred] set out to create a simple 8x8x8 LED cube gaming platform.

Rather than reinventing the wheel, [Andred] based the LED cube off of three separate Instructables. The resulting cube came out great, and the acrylic casing around it adds a very nice touch. Using an Arduino Mega, the 74HC574, and a few MOSFET’s to drive his LEDs, the hardware is fairly standard. What sets this project apart from many other LED cube builds, is the fact that you can game on it using a PlayStation 1 controller. All the necessary code to get up and running is included in the Instructable (commented in German). Be sure to see the cube in action after the break!

It would be great to see a wireless version of this LED cube game. What kind of LED cube will gaming be brought to next? A tiny LED cube? The biggest LED cube ever? Only time will tell.

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