FlowSense Alert

1/*
2Liquid flow rate sensor -DIYhacking.com Arvind Sanjeev
3
4Measure the liquid/water flow rate using this code. 
5Connect Vcc and Gnd of sensor to arduino, and the 
6signal line to arduino digital pin 2.
7 
8 */
9
10
11#include <TM1637Display.h>
12
13byte statusLed    = 11;
14
15#define CLK 5
16#define DIO 4
17
18// Initialize TM1637 display object
19TM1637Display display(CLK, DIO);
20
21// Interval for updating display (milliseconds)
22const unsigned long DISPLAY_UPDATE_INTERVAL = 1000; // Update every second
23
24//Water flow sensor pins 
25byte sensorInterruptA = 0;  // 0 = digital pin 2
26byte sensorInterruptB = 1; 
27byte sensorPinA       = 2;
28byte sensorPinB       = 3;
29
30
31// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
32// litre/minute of flow.
33float calibrationFactor = 4.5;
34volatile byte pulseCount;  
35
36float flowRate;
37float thresholdFlowRate = 2; // flow rate limit 
38unsigned long oldTime;
39
40void setup()
41{
42  
43  // Initialize a serial connection for reporting values to the host
44  Serial.begin(9600);
45   
46  // Set up the status LED line as an output
47  pinMode(statusLed, OUTPUT);
48  display.setBrightness(7); // Set brightness level (0 to 7)
49
50  pinMode(sensorPinA, INPUT);
51  pinMode(sensorPinB, INPUT);
52  digitalWrite(sensorPinA, HIGH);
53  digitalWrite(sensorPinB, HIGH);
54
55  pulseCount        = 0;
56  flowRate          = 0.0;
57  oldTime           = 0;
58
59  // The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
60  // Configured to trigger on a FALLING state change (transition from HIGH
61  // state to LOW state)
62  attachInterrupt(sensorInterruptA, pulseCounter, FALLING);
63  attachInterrupt(sensorInterruptB, pulseCounter, FALLING);
64}
65
66/**
67 * Main program loop
68 */
69void loop()
70{
71   
72   if((millis() - oldTime) > 1000)    // Only process counters once per second
73  { 
74    // Disable the interrupt while calculating flow rate and sending the value to
75    // the host
76    detachInterrupt(sensorInterruptA);
77    detachInterrupt(sensorInterruptB);
78        
79    // Because this loop may not complete in exactly 1 second intervals we calculate
80    // the number of milliseconds that have passed since the last execution and use
81    // that to scale the output. We also apply the calibrationFactor to scale the output
82    // based on the number of pulses per second per units of measure (litres/minute in
83    // this case) coming from the sensor.
84    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
85    
86    // Note the time this processing pass was executed. Note that because we've
87    // disabled interrupts the millis() function won't actually be incrementing right
88    // at this point, but it will still return the value it was set to just before
89    // interrupts went away.
90    oldTime = millis();
91
92 
93    unsigned int frac;
94    
95    // Print the flow rate for this second in litres / minute
96    Serial.print("Flow rate: ");
97    Serial.print(int(flowRate));  // Print the integer part of the variable
98    Serial.print(" L/min");
99    Serial.print("\t");       // Print tab space
100
101
102    // Display flow rate on all 4 digits
103    int flowRateInt=int(flowRate);
104    display.showNumberDec(flowRateInt, true);
105
106    // Reset the pulse counter so we can start incrementing again
107    pulseCount = 0;
108    
109    // Enable the interrupt again now that we've finished sending output
110      attachInterrupt(sensorInterruptA, pulseCounter, FALLING);
111      attachInterrupt(sensorInterruptB, pulseCounter, FALLING);
112
113      if (flowRate > thresholdFlowRate) {
114      digitalWrite(statusLed, HIGH); // Turn on buzzer
115      delay(500); // Buzzer on for 500ms
116      digitalWrite(statusLed, LOW);  // Turn off buzzer
117    }
118
119    
120  }
121}
122
123/*
124Insterrupt Service Routine
125 */
126void pulseCounter()
127{
128  // Increment the pulse counter
129  pulseCount++;
130}