!blog - corey menscher

Today I created a pair of digital chopsticks. Using the Arduino and breadboard, a pair of chopsticks, a force sensor, and some foil…I created a pair of chopsticks that when used correctly, activate some LED’s on the breadboard.

This sounds pretty boring, but it’s kind of interesting. The green LED lights only when the user holds the chopsticks properly. That is, they must put pressure on the top of the upper stick a few inches near the tip. This activates the force sensor. While the force sensor is being held down, the foil on the tips acts as a switch. If a user picks up a conductive material, or simply closes the chopsticks together, the yellow LED lights…but ONLY if the force sensor is also pressed (and the green LED is lit).

The logic is performed in the Arduino…the breadboard only holds the two voltage divider circuits so that one analog input and one digital input can be read by the Arduino. Here’s a video to demonstrate:

The labs were pretty basic, but definitely educational. Fortunately, I already had experience soldering. But I definitely had issues with the Serial and Parallel circuits…not the actual serialization and parallelization of the components, but more along the lines of having TOO much power.

Important safety tip…when depending on a voltage regulator, do not forget to plug your power to the input rather than the output. I accidentally did that, and instead of getting a nice 5V circult, I got a 12V pyrotechnics show of exploding LED’s. No injuries, other than maybe to my ego.

I am still having a hard time grasping how to use the multimeter. Hans was generous enough to explain how to measure amperage…which is the “i” in Ohm’s law (V=IR). I’m sure I’ll get the hang of it when we move to projects that really depend on it. Practice makes perfect, eh? Here’s some media:

So I’ve started the Lab.  I’ll be taking pictures to document it soon…but I’m loving it so far.  The act of building these circuits with my hands is exhilarating.  There’s nothing like that feeling when you see the LED light up for the first time.  I’ve soldered before, so I wasn’t apprehensive, but I’m still unsure using the multimeter.  I’m sure I’ll get it soon.