Hello everyone, i have a problem with the sensitivity of an LDR in a laser security system.
The main aim of my setup is to provide some extra security to a cupboard door with a servo, laser, LDR, a bluetooth module, and LCD.
There aren't any errors in the IDE, but in the program, the ldr is ver sensitive and even though the laser is shining on the LDR the whole time, the program still reports a small instance of the interruption. I think it is because of the initial analog value of the LDR.
Here is my code-
#include <LiquidCrystal.h>
#include <SoftwareSerial.h>
Servo myservo;
SoftwareSerial MyBlue(3, 2); // RX | TX
char relay = ' ';
const int rs = 13, en = 12, d4 = 11, d5 = 10, d6 = 9, d7 = 8;
bool arm = false;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup()
{ myservo.attach(4);
pinMode(7, OUTPUT);
pinMode(6, OUTPUT);
MyBlue.begin(9600);
lcd.begin(16, 2);
lcd.print("Good day!");
lcd.setCursor(0, 1);
lcd.print("No Entry.");
}
void loop()
{
delay(500);
relay = MyBlue.read();
flip(relay);
int value = analogRead(A0);
if (value < 50 && arm == true) {
delay(30);
MyBlue.write('x');
digitalWrite(5, HIGH);
lcd.clear();
lcd.print("INTRUDER");
delay(5000);
lcd.setCursor(0,1);
lcd.print("Reset prog.");
arm = false;
relay = '1';
flip(relay);
}
}
void flip(char yee){
if (yee == '0') { // Checks whether value of relay is equal to 1
digitalWrite(7, HIGH);
arm = true;
}
else if (yee == '1') // Checks whether value of relay is equal to 1
{ digitalWrite(7, LOW);
arm = false;
}
else if (yee == '2') {
myservo.write(90);
lcd.clear();
lcd.write("Please Enter.");
}
else if (yee == '3') { // Checks whether value of relay is equal to 1
myservo.write(0);
lcd.print("Good day!");
lcd.setCursor(0, 1);
lcd.print("No Entry.");
}
}
Also, i have a problem with me wanting to keep the function going after the intruder message is displayed.
Is it possible to fix that, or should I just press the reset button on the arduino every time an intruder is detected??
Me is a newbie so PLEEEEEZ help me
don't understand the purpose of the delays when you trigger. it seems like you trigger an alarm ("INTRUDER") for just 5 seconds. should there be a command sent over the serial I/F as well and should there be some command to reset the alarm?
re: sensitivity
maybe better to recognize a detection only after the level is below some threshold several times or over some period of times. rather than sampling once every 1/2 second
leaky integration is one approach averaging
avg += (samp - avg) * K; // K < 1.0
re: blocking
is there a need for any type of delay or timer? A timer could be used to check for the passing of some time without "blocking" the execution of other code
Oof, I'll fix that
It does look kind of easier with variables....
This, i think is an older version of the code, and removed pin 6 later.
Pin 5 is an active buzzer and pin 7 is a laser.
But, i am still struggling with the sensitivity.
Please show and explain the code here because i am doing this for door security.
OK, so the problem has changed. Now, the function(the one below) is being executed after the arm message and everything else is working fine. But now, there is a weird problem with it that the LCD shows some nonsensical values, like chars with accents when I tell it to move the servo and when it is armed and getting good values from the LDR. Here is my code.
#include <Servo.h>
#include <LiquidCrystal.h>
#include <SoftwareSerial.h>
Servo myservo;
int value;
int xyc;
float avg;
const float K = 1.0 / 8;
int n;
int samp = value;
SoftwareSerial MyBlue(3, 2); // RX | TX
char relay = ' ';
const int rs = 13, en = 12, d4 = 11, d5 = 10, d6 = 9, d7 = 8;
bool arm = false;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup()
{ Serial.begin(74880);
myservo.attach(4);
pinMode(5, OUTPUT);
pinMode(7, OUTPUT);
pinMode(6, OUTPUT);
MyBlue.begin(9600);
lcd.begin(16, 2);
lcd.print("Good day!");
lcd.setCursor(0, 1);
lcd.print("No Entry.");
}
void loop()
{ Serial.println(avg);
relay = MyBlue.read();
flip(relay, xyc);
avg += (samp - avg) * K;
value = analogRead(A0);
Serial.println(relay);
if (value < 30 && arm == true) {
MyBlue.write('x');
digitalWrite(5, HIGH);
lcd.clear();
lcd.print("IIINTRUDER");
xyc = + 1;
delay(5000);
arm = false;
relay = '0';
flip(relay, xyc);
}
if (value > 30) {
lcd.write("Armed.");
lcd.setCursor(0, 1);
lcd.write("Times stolen-");
lcd.print(xyc);
// Checks whether value of relay is equal to 1
digitalWrite(7, HIGH);
arm = true;
flip(relay, xyc);
}
}
void flip(char yee, int xyx) {
value = analogRead(A0);
if (yee == '0') {
lcd.clear();
lcd.write("Armed.");
lcd.setCursor(0, 1);
lcd.write("Times stolen-");
lcd.print(xyx);
// Checks whether value of relay is equal to 1
digitalWrite(7, HIGH);
arm = true;
}
else if (yee == '1')
// Checks whether value of relay is equal to 1
{ lcd.clear();
lcd.write("Disarmed.");
digitalWrite(7, LOW);
arm = false;
}
else if (yee == '2') {
myservo.write(90);
lcd.clear();
lcd.write("Please Enter.");
}
else if (yee == '3') { // Checks whether value of relay is equal to 1
myservo.write(0);
if (arm == true) {
lcd.write("Armed.");
lcd.setCursor(0, 1);
lcd.write("Times stolen-", xyx);
}
else {
lcd.clear();
lcd.write("Disarmed.");
}
}
}
OK, it is a normal hobby servo. SG90, to be specific.
Here is the datasheet Servo Motor Micro SG90 - ProtoSupplies
I will send a fritzing diagram as soon as I can.
I am powering it with a USB port on a 21 in desktop.
I have-
A normal 650 nm laser diode
A hobby servo (SG90)
An LDR (hooked up to A0)
An LCD
An HC-05
And an active buzzer.
And after looking at the datasheet of the servo, I know now that I messed up here.
You've already noticed the one potential problem, supplying the power for the servo.
So maybe think about powering the whole thing with an appropriately powerful 5 volt power supply or wall wart instead of through the USB and off the 5 volt output of the Arduino.
When are you going to add something like a pungent electric shock output for troublemakers?
FWIW I was the little brother, so here's me sticking my tongue out and never apologizing for reverse engineering your train set into a pile of worthless components.
For the record, I scribbled that whole thing in like 15 minutes. I was doing my homework.
I'll get back to you with a spray of water from a 12v pump on 24v
Yes, I will take the juice from a power bank or, since its stationary, maybe a wall adaptor. Before the first post on the forum, I cranked out this whole project on a bleak and dusty Sunday, wiring and all.
