Emulating A Z80 Computer With An AVR Chip

April 27, 2010 by Mike Szczys 13 Comments

[Sprite_tm] dusted off his assembly skills and managed to emulate a Z80 computer using an AVR ATmega88. He’s using an SD card in place of the floppy and a 128 KB DRAM chip to handle the memory for the emulated machine. An FT232 board gives him terminal access which he uses for input and display. As you can see, the hardware is much simpler than building the original would have been. He makes up for this with complicated firmware. In the end, the emulated core occupies about 2 KB of programming space after he followed the Z80 Propeller project’s idea of dividing the instructions into different modules and using a lookup table to access them.

Midi Piano Instructor

April 26, 2010 by Caleb Kraft 18 Comments

[youtube=http://www.youtube.com/watch?v=i7AfiCQQ4nE]

The MIDI piano instructor is a tool aimed at those who wish to learn to play piano, but don’t want to take lessons. The LED bar mounted above the keys lights up to show you exactly what key to press and when. We’ve seen this available in some electronic keyboards for some time, but this unit would be able to fit any standard sized keyboard. Check the page for schematics and pictures.

[via Flickr]

Update: IR Controlled Lighting

April 26, 2010 by Mike Szczys 11 Comments

[Muris] is back with another infrared controlled lighting hack. When we checked in with him last year he was showing off an IR controlled dimmer module. Now he’s back with this device that is CFL friendly. Because standard CFL bulbs are not dimmer compatible he’s adapted the project away from dimming and toward switching. The new design still uses an infrared remote but now it can turn two devices on and off again or toggle between them. Our favorite part of the build is that the PIC based device can learn the codes of whichever remote you choose, rather than having to rely on one specific type of remote.

Spinning Ball Of LED Awesomeness

April 26, 2010 by Caleb Kraft 63 Comments

[youtube=http://www.youtube.com/watch?v=sO2-tqoyGik]

Take a few moments and watch this 3 axis rotating LED light display fire up. The final effect of being an RGB glowing ball is nice, but we’re fascinated with the structure. There are tons of great detailed pictures of the assembly on the forum thread to feast your eyes on. Just getting power to the LEDs was a feat, he passes their power through 6 slip contacts. Parts were pulled from an old VCR and some old fans.

[via HackedGadgets]

Apple IIe Twitter ticker

April 24, 2010 by Mike Szczys 18 Comments

A hand input bootloader and a custom communications protocol are what bring the Apple IIe Twitter ticker to life. [Chris Yerga] bought the decades-old machine for $20 at a flea market. Having just completed his TweetWall he decided to adapt the idea for the 1 MHz machine. He manually input a 50 byte bootloader that would let him dump programs into memory via the joystick port. From there he rigged up a connection with a USB FTDI cable. Now the images and text are processed by a modern-day machine and fed to the Apple IIe at 3600 baud. See this in action after the break.

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VFD As A Sound Amplifier

April 22, 2010 by Mike Szczys 16 Comments

[Alessandro Lambardi] had some vacuum flourescent displays that he pulled from junked VCRs. His latest project is an experiment to use one of the VFDs as a headphone amplifier (Wayback Machine Cache). This means he’s trying to use them as vacuum triode amplifiers, aka vacuum tubes. He did get it to work but as he suspected, the output is fairly low power. It may be possible to use this setup as a preamp and build an actual tube amp to use along with it.

Update: Thanks to [Fallen] for mentioning that we’ve covered this concept in the past.

[Thanks Muris]

Automated Guitar Pickup Winding

April 20, 2010 by Mike Szczys 21 Comments

[Robert Pickering] shares his automated guitar pickup winder with us. He built it for his senior project at Old Dominion University. Two stepper motors are used to wind the magnet wire around the pickup hardware. The unit is PIC based and about six minutes into the video (embedded after the break) you can see that he used wire wrapping for this build. Curious, one of the comments on our latest Hackaday Links mentioned that wire wrapping was rarely used anymore, but here it is anyway.

We especially like the limiting switches he’s using on the traverse mechanism. There are momentary push buttons on either side of a carriage which are depressed when a drywall screw in the sides of that carriage hits them. This makes for very easy calibration because the screw can be raised or lowered with just a bit of screwdriver work. Well built and documented, we’re sure he’ll get some high marks on this one. Continue reading “Automated Guitar Pickup Winding” →