As the title suggests, the objective of this setup is to control a servo motor with an arduino. The control values will be passed to the arduino from a potentiometer. The schematic is shown below.
(image courtesy of itp. The complete tutorial and the arduino code is here.)
So taking Rory's lab as a point of departure, I decided to add a few elements to spice things up a bit. In this demo, instead of using a potentiometer to control the brightness of the LED, I'll be using sound. That is, the loudness of the sound determines how bright or soft the LED will glow - the louder the sound, the brighter the LED.
I used a simple audio pre-amp that was lying around on my breadboard from a previous project to setup the input. The schematic is shown below. The output from the pre-amp section (figure 1) goes into a line driver stage (figure 2, optional, just to steady things a bit and in case you want a 3 wire configuration instead of a 2 wire) and then into the analog in of the arduino ( instead of the potentiometer as in Rory's session). The rest of the circuit (from arduino out to LED) and the code is the same as Rory's. Here's the video.
I couldn't find a steady monotone to experiment with (my voice failed miserably and I don't own an oscillator). So in the second part of the video I'm using a sruthi box (the next best thing I could find). Notice the LED on the left of the screen.
Car Horn Opening an umbrella Automatic Wheel Chair (I live next to an old age home) Automatic Doors (with reference to the aforementioned old age home) Shop shutters Street light switch Coke Machine The order screen at White Castle Credit card machine