Build your own Arduino Controlled Sip-and-Puff switch.
Sip-and-Puff (SNP) controllers are nothing new - you've probably seen one in action yourself. SNPs are often seen on electric wheelchairs and allow individuals who can't use their hands to control their wheelchairs (or whatever else) by either "sipping" (inhaling) or "puffing" (exhaling) into a straw. Depending on how hard the individual inhales or exhales, it makes the wheelchair respond differently. It's a pretty amazing technology that has changed the lives of millions of people for the better.
An illustration of the Arduino Controlled Sip-and-Puff.
If you are counting on a sip-and-puff switch for something like controlling a wheelchair, it is probably in your best interest to have a professionally built one that can be perfectly calibrated. But what if you want to build an SNP controller for something else? SNP controllers can run upwards of $400 and if you want to, say, build an SNP controlled joystick for a video game or some other use, buying an actual SNP might be cost prohibitive.
The schematic for the Arduino SNP. Click on the image for a larger version.
That is where this next project comes in. Check out the Arduino Controlled Sip-and-Puff. Using an Arduino, some pressure/vacuum switches, tubing, and some clever programming, this SparkFun customer made a DIY SNP controller that can be integrated into thousands of projects. This is an amazing project with some very useful real-world applications. It is always great to see SparkFun parts used in a way that can truly benefit society - it warms our nerdy little hearts.