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hello guys, i am doing this project to detect earthquake, when there is still movement after 5 seconds the arduino will activate the relay. My problem is the timer resets immediately when the sensor goes back to its original position so the 5 second timer does not end and it keeps resetting.
i used adxl 335 accelerometer sensor
here is my code:
#define buzzer 12 // buzzer pin
#define led 13 //led pin
#define relay 11 // relay pin
#define x A0 // x_out pin of Accelerometer
#define y A1 // y_out pin of Accelerometer
#define z A2 // z_out pin of Accelerometer
/*variables*/
int xsample = 0;
int ysample = 0;
int zsample = 0;
long start;
unsigned long movementStarted;
unsigned long currentMillis;
unsigned long period = 5000;
/*Macros*/
#define samples 50
#define maxVal 4 // max change limit
#define minVal -4 // min change limit
bool moving = false;
void setup()
{
pinMode(buzzer, OUTPUT);
pinMode(led, OUTPUT);
pinMode(relay, OUTPUT);
for (int i = 0; i < samples; i++) // taking samples for calibration
{
xsample += analogRead(x);
ysample += analogRead(y);
zsample += analogRead(z);
}
xsample /= samples; // taking avg for x
ysample /= samples; // taking avg for y
zsample /= samples; // taking avg for z
delay (3000);
}
void loop()
{
currentMillis = millis();
int value1 = analogRead(x); // reading x out
int value2 = analogRead(y); // reading y out
int value3 = analogRead(z); // reading z out
int xValue = xsample - value1; // finding change in x
int yValue = ysample - value2; // finding change in y
int zValue = zsample - value3; // finding change in z
// Check if there is currently movement.
if (xValue < minVal || xValue > maxVal || yValue < minVal || yValue > maxVal || zValue < minVal || zValue > maxVal)
{
if (moving == false) // Did we just started moving?
{
movementStarted = currentMillis; // Capture the time we started moving
tone(buzzer, 1000);
}
moving = true; // Flag that we are moving
if (currentMillis - movementStarted > period) // Check how long we have been moving for
{
digitalWrite(relay, HIGH);
}
}
else // Not moving.
{
moving = false; // Flag that we are not moving
noTone(buzzer);
// Turn relay OFF (active LOW)
}
}
Hi vjcp,
I do not have an accelerometer available (or earthquakes for that matter 😋 ).
This is an interesting challenge for sure though.
One key problem would be this:
Say we detection motion at 0 seconds. And again at 1 second, 2 seconds, 4 seconds, and ... 6 seconds.
This could be seen as an earthquake detection, right? But when we strictly stick to 5 seconds it would not be seen as such.
Maybe we'd need to define clearer what is considered motion that indicates an earth quake.
For example:
X number of motion detection within 5 seconds?
Or at the most X seconds between two motion detections?
Note: I'd make a separate function for motion detection to make code more readable. Something like this (returns true or false):
bool motionDetected()
{
int value1 = analogRead(x); // reading x out
int value2 = analogRead(y); // reading y out
int value3 = analogRead(z); // reading z out
int xValue = xsample - value1; // finding change in x
int yValue = ysample - value2; // finding change in y
int zValue = zsample - value3; // finding change in z
return (xValue < minVal || xValue > maxVal || yValue < minVal || yValue > maxVal || zValue < minVal || zValue > maxVal);
}
p.s. maybe this article is helpful for your project?
Is this the project you got your code?