Anemometer

1#include <Wire.h>
2
3#include <Wire.h>
4#include <TM1637Display.h>
5
6// TM1637 displays
7#define CLK_TIME 8
8#define DIO_TIME 7
9
10TM1637Display dispSpeed(CLK_TIME, DIO_TIME);
11
12volatile unsigned long pulseCount = 0;
13
14#include <TM1637Display.h>
15
16// TM1637 displays
17#define CLK_TIME 8
18#define DIO_TIME 7
19
20TM1637Display dispSpeed(CLK_TIME, DIO_TIME);
21
22volatile unsigned long pulseCount = 0;
23
24unsigned long lastMeasure = 0;
25static unsigned long lastPulseTime = 0;
26const int pulsesPerRevolution = 8;
27const float radius = 0.09;  // meters (90 mm)
28
29bool showKmh = true;
30unsigned long lastToggle = 0;
31
32float v_kmh = 0;
33float v_ms = 0;
34float v_kmh_filtered = 0;
35float v_ms_filtered = 0;
36
37void setup() {
38  Serial.begin(115200);
39  pinMode(2, INPUT_PULLUP);
40  attachInterrupt(digitalPinToInterrupt(2), countPulse, FALLING);
41
42  // init your display here if needed
43  dispSpeed.setBrightness(0x0f);
44
45  Serial.print("Test started");
46  Serial.println(" LastSecond:  ");
47}
48
49void loop() {
50  unsigned long now = millis();
51
52  if (now - lastMeasure >= 1000) {  // every 1 second
53    noInterrupts();
54    unsigned long count = pulseCount;
55    pulseCount = 0;
56    interrupts();
57
58    if (millis() - lastPulseTime > 1500) {
59      v_kmh = 0;
60      v_kmh_filtered = 0;
61    }
62
63    if (millis() - lastToggle >= 2000) {
64      showKmh = !showKmh;
65      lastToggle = millis();
66    }
67
68    if (count < 2) {
69      v_kmh = 0;
70      v_kmh_filtered = 0;  // ← force immediate zero
71    } else {
72      // rotations per second
73      float rps = count / (float)pulsesPerRevolution;
74      // linear speed of cups
75      float v_cups = 2 * PI * radius * rps;
76      // estimated wind speed
77      float v_wind = v_cups / 0.7;
78      v_kmh = v_wind * 3.6;
79      v_ms = v_kmh / 3.6;
80      // apply smoothing ONLY when moving
81      v_kmh_filtered = 0.7 * v_kmh_filtered + 0.3 * v_kmh;
82      v_ms_filtered = v_kmh_filtered / 3.6;
83    }
84
85    // simple smoothing (important for display stability)
86    v_kmh_filtered = 0.7 * v_kmh_filtered + 0.3 * v_kmh;
87    v_ms_filtered = 0.7 * v_ms_filtered + 0.3 * v_ms;
88
89    int whole_k = (int)v_kmh_filtered;
90    int whole_m = (int)v_ms_filtered;
91    int decimals_k = (int)((v_kmh_filtered - whole_k) * 100 + 0.5);
92    int decimals_m = (int)((v_ms_filtered - whole_m) * 100 + 0.5);
93
94    if (decimals_k >= 100) {
95      whole_k++;
96      decimals_k = 0;
97    }
98    if (decimals_m >= 100) {
99      whole_m++;
100      decimals_m = 0;
101    }
102    // convert for display (XX:YY)
103    int displayValue_k = whole_k * 100 + decimals_k;
104    int displayValue_m = whole_m * 100 + decimals_m;
105
106    // show 00:00 if stopped
107    if (v_kmh_filtered < 0.1) {
108      displayValue_k = 0;
109      displayValue_m = 0;
110      v_ms_filtered = 0;
111    }
112
113    if (v_ms_filtered < 0.1) {
114      
115    }
116
117    // show with colon
118    dispSpeed.showNumberDecEx(displayValue_m, 0b01000000, false);
119
120    Serial.print("Wind speed: ");
121    Serial.print(v_ms_filtered);
122    Serial.print(" m/s \t");
123    Serial.print(v_kmh_filtered);
124    Serial.println(" km/h");
125
126    lastMeasure = now;
127  }
128}
129
130void countPulse() {
131  pulseCount++;
132  lastPulseTime = millis();
133}