DIY Shock Sensor

-
A speaker works by activating an electromagnet which is nearby a "regular" magnet. This produces vibration, resulting in sound. So if instead of supplying current to the speaker, we can produce current (if very little) by moving the speaker itsself. This current can then be detected and interpreted by a microcontroller such as the Arduino.

Step 1: Find a Speaker



You will need to find a speaker that you are willing to sacrifice for this project. You can buy one at SparkFun for under a dollar, but you probably already have one somewhere. I used a small speaker from an old pair of headphones, but you can find one almost anywhere - like a musical greeting card or an old alarm clock. Next:
  • Cut a jumper wire in half
  • Strip the ends of it
  • Solder it onto the speaker (there were probably already some wires on there - just cut them off)
  • Alternatively, you could use alligator clips if you have them.

Step 2: Build the Circuit 

Materials needed:
  • Arduino UNO
  • Breadboard
  • Jumper wires
  • An led (any color)
  • Two 220 ohm resistors (red-red-brown)
  • A speaker
  • Follow the above diagram to connect it all to the Arduino.

Step 3: Upload This Code

Upload this code in the Arduino IDE. You will probably need to calibrate it since you are not using the same speaker as me, so I'll explain how to do that in a few steps.
int shockMin = 996;  //you might need to change these
int shockMax = 1010;  //you might need to change these
void setup() {
  pinMode(11, OUTPUT);
  // Serial.begin(9600); //uncomment this to help with calibration
}
void loop() {
  int shock = analogRead(A0);
  int lightval = map(shock, shockMin, shockMax, 0, 255);
  if (lightval > 0) {
    analogWrite(11, lightval);
  }
  else {
    analogWrite(11, 0);
  }
  // Serial.println(shock); //uncomment this to help with calibration
}

Step 4: How to Use It

Press on the center of the speaker with your finger and it should make the led blink. If not, you will need to calibrate it in the next step. Otherwise, you can try attaching the speaker to something. Maybe you could make a drum by taping it to a paper plate? - Try using pencils as drumsticks.

Step 5: Calibrate

If your led is already blinking satisfactorily, you can skip this step. Otherwise, follow these steps:
  • Delete the "//" on the lines that say "//uncomment this to help with calibration"
  • Upload the code and open the serial monitor
  • Press on the center of the speaker and watch as the values change
  • Change the shockMin and shockMax variables to the low and high values in the serial monitor
int shockMin = 996; 
int shockMax = 1010;
For example, if the serial monitor reads 700 as the non-pushed state of your sensor (when it's just sitting there), and when you push it it goes up to 860, change the shockMax to somewhere around 900 (just a little above the sensor reading) and the shockMin to about 680. Next:
  • Close the serial monitor
  • Upload the new code
  • Press on the center of the speaker some more
If it all goes right, the led should turn on only when you press the sensor.

Popular posts from this blog

Arduino LED Temperature Indicator

-
Image
Above is a simuation.  Click the "Start Simulation" button to begin.  Click on the sensor labled "TMP" to change its value: the LEDs will light themselves according to the sensor's reading. This design is made to keep track of the temperature in a room. You give it the parameters you want and it will light a blue LED if it is too cold, a red LED if it's too hot, and a green one if it's just right. You will need: Arduino board:  https://amzn.to/2DLjxR2 Breadboard:  https://amzn.to/2RYqiSK Jumper wires:  https://amzn.to/2Q7kiKc 3 220Ω resistors (red-red-brown):  https://amzn.to/2S2sV5R 3 LEDs (colors of your choice):  https://amzn.to/2S5PFlM A temperature sensor (mine is an LM35, but most should work):  https://amzn.to/2ORLHuQ Step 1: Make the Circuit Red LED goes to digital pin 4 through one of the resistors, and ground Green LED goes to digital pin 3 though a resistor, and ground Blue LED goes to digital pin 2 through
Read more

Rubber Band Gatling Gun Turret (Arduino)

-
Image
T his is an Arduino controlled rubber band Gatling  gun.  It can hold about 20 rubber bands and it is operated with a USB game controller through processing.  The complete bill of materials can be seen below: Arduino UNO https://amzn.to/2DLjxR2 Jumper cables https://amzn.to/2Q7kiKc Breadboard https://amzn.to/2RYqiSK Servo motors https://amzn.to/2S6E5GZ Gear motor https://amzn.to/2DQUr3u Rubber bands https://amzn.to/2S8zgwR Electrical tape https://amzn.to/2BpvF8a Lego pieces https://amzn.to/2DROMtU Craft sticks (big) https://amzn.to/2zldtuH Craft sticks (small) https://amzn.to/2zldG0X Hot glue sticks https://amzn.to/2TCRND4 Binder clips https://amzn.to/2KnZWa3 Clothespins https://amzn.to/2BpOw2K Cardboard https://amzn.to/2BpOSGC Lazy susan https://amzn.to/2OVr4xH Diode https://amzn.to/2DPaVcn
Read more

DIY Plant Moisture Sensor

-
Image
This project will calculate the water content of soil around a plant by measuring the dielectric constant (the soil's ability to transmit electricity) and will alert you with a red LED when the plant needs more water or a blue one when it has too much. Step 1: Materials You will need to gather these things in order to build this project: Arduino UNO or equivalent (x1):  https://amzn.to/2DLjxR2 220Ω* resistors (for LED) (x3):  https://amzn.to/2S2sV5R 10kΩ resistor (x1) - brown black orange:  https://amzn.to/2S2sV5R RGB LED (x1) or 3 different colored LEDs:  https://amzn.to/2Fzbusx Long Jumper Cables (x2):  https://amzn.to/2Q7kiKc Jumper Cables (x6):  https://amzn.to/2Q7kiKc Breadboard (x1):  https://amzn.to/2RYqiSK Bolts of any size (x2):  https://amzn.to/2qWLYTF Nuts same diameter as bolts above (x2):  https://amzn.to/2qWLYTF * red-red-brown Step 2:  Create Sensor Prongs You will need to repeat this step twice (once for each prong): Begi
Read more