I wanted a tripwire. This is just the circuit and the code, you can use it for quite a few things, like a trigger for a camera, or you could make it shut down your computer if someone crosses it.
When I have the time, I want to hook it up to an electric airsoft gun with a relay and have it shoot you when you break the beam. I suppose I'll add to the Instructable when that happens.
So let's start!
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Signing UpStep 1: Components Needed
-Arduino
-10k Resistor
-Photo resistor (Practically any value will work, the program will just need to be changed slightly)
-Laser Pointer
-Jumper Cables
-Alligator clips





































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and wont run
please help ?
thanx
If you just copy and paste the code has there, it won't work.
void setup() {
pinMode(4, OUTPUT);
pinMode(13, OUTPUT);
}
void loop(){
digitalWrite(4, HIGH);
if(analogRead(0) < 750){
digitalWrite(13, HIGH);
} else{
digitalWrite(13, LOW);
}
}
void setup() {
pinMode(4, OUTPUT);
Serial.begin(9600);
}
void loop(){
digitalWrite(4, HIGH);
Serial.println(analogRead(0));
}
Those two seperate sections of code need to be combined, as thse are both programs in their own right. From memory it should be something similar to this:
void setup() {
pinMode(4, OUTPUT);
pinMode(13, OUTPUT);
Serial.begin(9600);
}
void loop(){
digitalWrite(4, HIGH);
if(analogRead(0) < 750){
digitalWrite(13, HIGH);
} else{
digitalWrite(13, LOW);
Serial.println(analogRead(0));
}
}
Please not though that each of those segments of code were designed for a seperate task; one to simply trigger an LED when the beam is broken, the other to send data from the LDR to the computer so that Processing may be used. The combined code does both of these tasks, although you pobably don't need the serial transfer section if you had an error like that that you couldn't fix. Most of the people who will want to try this will be content with the first segment of code; that is, just turn on an LED or similar device when the beam is broken. The second piece of code is for more advanced users who wish to create a monitoring program in Processing (probably not you).
Hope this helped.
-Archive
What I want to achieve is to have a computer screen using the mirror function in Processing and camera that is triggered by a person entering the space. Ideally the camera should track the person so that they can never see their own face in the mirror but that might be a bit ambitious for my skils / knowledge level at present.
Thanks in anticipation,
Frank
from the motion and tracking thing. I bet you could modify his code for what your wanting to do.
http://gallactronics.blogspot.in/2011/11/laser-people-counter.html
Thanks
You're onto a very smart idea to make it frequency dependent. Then there would be a good reason to use the Arduino. (The project as it is can be done with a transistor, trimpot, couple of resistors, LDR and LED)
I do think that's a great instructable though.
Brian Whatcott
Place the sensor at the back end of a black tube to block ambient light.
if(analogRead(0) = analogRead(1)) {
digitalWrite(13, LOW);
it doesnt work though! :S but the principle is close right? lol
And I would turn on the light if they are within a certain percentage of each other, so it would be:
if(analogRead(0) - (.25 * analogRead(1)) < 0) {
digitalWrite(13, LOW);
}
Or at least something like that