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34 Articles

Collect And Analyze ECG Data

August 22, 2009 by 14 Comments

ecg

Although we’ve covered DIY ECGs before, [Scott Harden] sent in his version that gives an in-depth explanation of what to do with the collected data. He built a basic battery-powered op-amp-based ECG for under $1. The circuit just amplifies the signal from the chest leads and feeds it into a computer via the microphone port. He then used GoldWave to record, filter, and save the signal. From there, he used python to analyze the heartbeat and calculate his heart rate and further manipulate the data. His previous blog posts go into more detail on how the python code works and why he chose software over hardware filters.

Custom Flex Sensors

July 25, 2009 by 14 Comments

flex

Flex sensors, like the ones used in the Nintendo Power Glove, are generally expensive and hard to find. However, [jiovine] demonstrates that they are easy enough to make from spare parts. He sandwiched a strip of plastic from ESD bags between pieces of copper foil, and wrapped the whole thing in heat shrink tubing. The sensor is able to detect bends in either direction, unlike the original power glove sensors. His version had a nominal resistance of about 20k ohms, but by choosing a different resistive layer you could create sensors that are more or less resistive.

Related: 5-cent tilt sensor

Gimbal Camera Stabilizer

July 15, 2009 by 38 Comments

steadycam

Professional cameramen use steadicams to make their shots look smooth and clean. However, their prices are generally way too high for an indie’s budget. Previous attempts have tried adding a counterweight and moving the camera away from the hands. [YB2Normal] took a different method and used a bob and gimbal to hold the camera upright. The gimbal is free to rotate along 3 axes, so the camera can stay in place. The whole thing cost less than $15. The first video he made with he mount is after the break.

[youtube http://www.youtube.com/watch?v=nXB0ncUQLn4%5D

Related: Building a Snorricam

[via Gizmodo]

Cheap ARM Color LCD Platform

July 18, 2008 by 6 Comments


Today, [sprite_tm] let us in on one of his pet projects. This is an inexpensive portable game platform runs about $50 and happens to use an ARM CPU and a 320×240 color LCD. Because it’s so cheap, he’s been working on reverse engineering the thing and there’s already a proof of concept homebrew version of Pong out for it.
Update: Yeah, yeah – title’s fixed.

Ard-e: Cheap Arduino Robot Platform

July 14, 2008 by 5 Comments


[Adam] sent in his robot: Ard-e. It’s build on a cheap remote control bull dozer kit along with a pile of cheap parts. He managed to keep the cost under $100. You might be getting sick of the Arduino love, but we love how the platform makes it possible for the micro controller novice to get results without taking advanced assembly language.

Cheap Projector Repair

May 22, 2008 by 31 Comments


[Ryan] sent in this writeup on some DIY projector repair. The write-up is a little hard to follow, but maybe it’ll inspire some future projector landfill saves. [Dissident] replaced the light bulb and ballast in an older DLP projector with some salvaged MR-16 hardware from an even older over head projector. The main trick required was to bridge the trigger leads that tell the projector that the bulb is on and working.