Hard Drive Becomes Hard Drive Activity Light; Stores no Data

A while ago [Frank Zhao] built a computer in an aquarium. It’s exactly what you would expect – a bunch of parts stuffed into a container filled with mineral oil. Yes, there’s an i7 and a GTX970 in there, but there’s also a bunch of neopixels and a neat little bubbling treasure chest. That wasn’t enough for [Frank], and he wanted to add a HDD activity monitor. What’s the most absurd activity monitor for an SSD? An old platter-based drive, of course.

The build is relatively simple and something [Frank] put together from spare parts in a day. After cracking open an old PATA hard drive, the voice coil for the hard drive arm was connected to the motherboard’s HDD activity signal through a few MOSFETs. The platter motor is controlled by an MTD6501 motor driver, set to spin up when the circuit is on.

It’s a kludge as far as controlling the components of a hard drive go, but that’s not really the point. It’s just a neat project to show when the SSD in the aquarium computer is being accessed. That said, the activity monitor is currently disconnected because the old HDD is so freakin’ loud. It looks really cool, though.

Open Activity Tracker Webcast

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The Upverter team loves their FitBit activity tracking devices, but wanted access to raw data. They decided to build their own Open Activity Tracker that would pump data onto an SD card or to a Bluetooth device for processing.

The device uses MPU-9150 motion tracking IC to gather information on movement. This chip combines an accelerometer, gyro, and compass. It also does on-board processing, providing useful data to your host processor over I2C. The only bad news is that it’s a LGA package, which aren’t fun to solder by hand.

The design also has a SD card, Bluetooth module, pressure sensor, and e-ink display. These are all connected to a low power ARM microcontroller.

The team has been webcasting their design sessions, and tonight [Eric Evenchick] (that’s me) will be joining them as they try to cram all of these components onto a PCB. You can watch the live webcast starting at 8:30pm Eastern.

You can watch the previous design sessions after the break.

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