Surround Sound system controller replacement includes home automation

[Neoxy] always wanted surround sound for his computer, and one day he managed to get a hold of a dead 5.1 system. Why buy one when you can repair someone’s rubbish, right? That turned out to be easier said than done, but after several false-starts he managed to resurrect the audio system by replacing the microcontroller.

We find his trouble-shooting technique interesting. The amp would power up without a hitch but no sound would come out of it. So he took a headphone cable and used the L and R conductors as probes. That cable was fed from an MP3 player, and by touching the probes to the audio inputs for the pre-amp and amplifier circuits he could get great sound out of the speakers. Reasonably certain that those boards were working fine he narrowed down the troubles to three chips that mix, select inputs, and control the system.

A lot of prototyping with an ATmega328 and an Arduino led him to the functionality you see in the video after the break. Not only did he get the system working, but he’s using the Arduino to add Internet control for the device.

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Motor controller also does nyan cat

As a freshman at UC Berkeley, [Keegan] has been helping out with his school’s Pioneers in Engineering program that gives high school students some hands on experience with engineering principles, usually by building robots. This year, [Keegan]’s project is a motor controller that just so happens to play the nyan cat song over the motor PWM output.

The motor controller is meant to replace the Pololu simple motor controller the PiE team is currently using. Onboard is an H-bridge chip and an ATmega328 that takes commands from an I2C bus. The ‘328 is loaded up with the Arduino bootloader making the firmware very accessible – a good thing for the high school students that will be building and programming these robots.

[Keegan] put up the Eagle files for the board up on the PiE Wiki. For now, just enjoy the dulcet tones of the pop tart cat theme song after the break.

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POV clock spins light filter instead of LEDs

This hard-drive based POV clock is a treasure trove of great design choices. Now, we’ve seen a bunch of spinning clock builds. Several of the hard drive versions use slits cut in the platters to create a display by illuminating an LED behind those slits at just the right moment. This is a similar idea but [Jason Hotchkiss] ditched the platters all together and replaced them with a light filter. The filter disc has digits 0-9 as well as a colon (not seen above because the colons blink each second). As this disc spins, the Arduino compatible controller lights up LEDs in the eight digital positions to illuminate the correct number.

The filter is made from an etched copper-clad disc. This is a great choice because the fiberglass substrate is strong, light weight, translucent, and available. The filter idea also means you don’t need to get power or data to a spinning platform. [Jason] has also designed a very impressive controller board that is the same size as the footprint of the laptop hard drive he’s using. Check out the video after the break to see his description of what went into the hardware choices he arrived upon. [Read more…]