3-axis accelerometer motion detector project

 1
 2
 3
 4
 5
 6
 7
 8
 9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219

//Motion Detector Alarm - Written by ScottC on 2/08/2012

//Global Variables and constants
constint buttonPin = A0; // button Pin connected to Analog 0
constint buzzerPin = A1; // buzzer Pin connected to Analog 1


//Accelerometer Pins
constint x = A3; // X pin connected to Analog 3
constint y = A4; // Y pin connected to Analog 4
constint z = A5; // Z pin connected to Analog 5


//Alarm LED
constint ledPin = 8; // LED connected to Digital 8



int tolerance=20; // Sensitivity of the Alarm
boolean calibrated=false; // When accelerometer is calibrated - changes to true 
boolean moveDetected=false; // When motion is detected - changes to true



//Accelerometer limits
int xMin; //Minimum x Value
int xMax; //Maximum x Value
int xVal; //Current x Value

int yMin; //Minimum y Value
int yMax; //Maximum y Value
int yVal; //Current y Value

int zMin; //Minimum z Value
int zMax; //Maximum z Value
int zVal; //Current z Value



void setup(){
//Begin Serial communication
 Serial.begin(38400);

//Initilise LED Pin
 pinMode(ledPin, OUTPUT);

}



void loop(){
// If the button is pressed, initialise and recalibrate the Accelerometer limits.
if(analogRead(buttonPin)>500){
 calibrateAccel();
 }

// Once the accelerometer is calibrated - check for movement 
if(calibrated){
if(checkMotion()){
 moveDetected=true;
 } 
 }

// If motion is detected - sound the alarm !
if(moveDetected){
 Serial.println("ALARM");
 ALARM();
 delay(1000);
 }

}





//This is the function used to sound the buzzer
void buzz(int reps, int rate){
for(int i=0; i<reps; i++){
 analogWrite(buzzerPin,900);
 delay(100);
 analogWrite(buzzerPin,0);
 delay(rate);
 }
} 




// Function used to calibrate the Accelerometer
void calibrateAccel(){
// reset alarm
 moveDetected=false;

//initialise x,y,z variables
 xVal = analogRead(x);
 xMin = xVal;
 xMax = xVal;

 yVal = analogRead(y);
 yMin = yVal;
 yMax = yVal;

 zVal = analogRead(z);
 zMin = zVal;
 zMax = zVal;

// Calibration sequence initialisation sound - 3 seconds before calibration begins
 buzz(3,1000);

//calibrate the Accelerometer (should take about 0.5 seconds)
for (int i=0; i<50; i++){
// Calibrate X Values
 xVal = analogRead(x);
if(xVal>xMax){
 xMax=xVal;
 }elseif (xVal < xMin){
 xMin=xVal;
 }

// Calibrate Y Values
 yVal = analogRead(y);
if(yVal>yMax){
 yMax=yVal;
 }elseif (yVal < yMin){
 yMin=yVal;
 }

// Calibrate Z Values
 zVal = analogRead(z);
if(zVal>zMax){
 zMax=zVal;
 }elseif (zVal < zMin){
 zMin=zVal;
 }

//Delay 10msec between readings
 delay(10);
 }

//End of calibration sequence sound. ARMED.
 buzz(3,40);
 printValues(); //Only useful when connected to computer- using serial monitor.
 calibrated=true;

}



//Function used to detect motion. Tolerance variable adjusts the sensitivity of movement detected.
boolean checkMotion(){
 boolean tempB=false;
 xVal = analogRead(x);
 yVal = analogRead(y);
 zVal = analogRead(z);

if(xVal >(xMax+tolerance)||xVal < (xMin-tolerance)){
 tempB=true;
 Serial.print("X Failed = ");
 Serial.println(xVal);
 }

if(yVal >(yMax+tolerance)||yVal < (yMin-tolerance)){
 tempB=true;
 Serial.print("Y Failed = ");
 Serial.println(yVal);
 }

if(zVal >(zMax+tolerance)||zVal < (zMin-tolerance)){
 tempB=true;
 Serial.print("Z Failed = ");
 Serial.println(zVal);
 }

return tempB;
}





// Prints the Sensor limits identified during Accelerometer calibration.
// Prints to the Serial monitor.
void printValues(){
 Serial.print("xMin=");
 Serial.print(xMin);
 Serial.print(", xMax=");
 Serial.print(xMax);
 Serial.println();

 Serial.print("yMin=");
 Serial.print(yMin);
 Serial.print(", yMax=");
 Serial.print(yMax);
 Serial.println();

 Serial.print("zMin=");
 Serial.print(zMin);
 Serial.print(", zMax=");
 Serial.print(zMax);
 Serial.println();

 Serial.println("------------------------");
}




//Function used to make the alarm sound, and blink the LED.
void ALARM(){

//don't check for movement until recalibrated again
 calibrated=false;

// sound the alarm and blink LED
 digitalWrite(ledPin, HIGH);
 buzz(4,20);
 digitalWrite(ledPin, LOW);
}