Arduino Radar Scanner with OLED Display and Servo Sweep Visualization

1#include <Servo.h>
2#include <Wire.h>
3#include <Adafruit_GFX.h>
4#include <Adafruit_SSD1306.h>
5
6#define SCREEN_WIDTH 128
7#define SCREEN_HEIGHT 64
8#define OLED_RESET    -1
9Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
10
11#define TRIG_PIN 9
12#define ECHO_PIN 10
13#define SERVO_PIN 11
14
15Servo servo;
16const int maxDistance = 50; 
17const int centerX = SCREEN_WIDTH / 2;
18const int centerY = SCREEN_HEIGHT - 1;
19const int maxRadius = 50; 
20
21struct Blip {
22  float angle;
23  int distance;
24  unsigned long timestamp;
25  bool active;
26};
27
28Blip blips[20];  
29int blipCount = 0;
30unsigned long lastUpdate = 0;
31const long fadeTime = 3000; 
32
33void setup() {
34  pinMode(TRIG_PIN, OUTPUT);
35  pinMode(ECHO_PIN, INPUT);
36  servo.attach(SERVO_PIN);
37  servo.write(0);
38
39  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
40    for(;;); 
41  }
42  display.clearDisplay();
43  display.display();
44}
45
46float measureDistance() {
47  digitalWrite(TRIG_PIN, LOW);
48  delayMicroseconds(2);
49  digitalWrite(TRIG_PIN, HIGH);
50  delayMicroseconds(10);
51  digitalWrite(TRIG_PIN, LOW);
52  
53  long duration = pulseIn(ECHO_PIN, HIGH, 30000); 
54  if (duration == 0) return maxDistance;
55  
56  float distance = duration * 0.034 / 2;
57  return (distance > maxDistance) ? maxDistance : distance;
58}
59
60void addBlip(float angle, int distance) {
61  if (blipCount < 20 && distance < maxDistance) {
62    blips[blipCount].angle = angle;
63    blips[blipCount].distance = distance;
64    blips[blipCount].timestamp = millis();
65    blips[blipCount].active = true;
66    blipCount++;
67  }
68}
69
70void updateBlips() {
71  unsigned long currentTime = millis();
72  for (int i = 0; i < blipCount; i++) {
73    if (blips[i].active && (currentTime - blips[i].timestamp > fadeTime)) {
74      blips[i].active = false;
75      
76      for (int j = i; j < blipCount - 1; j++) {
77        blips[j] = blips[j + 1];
78      }
79      blipCount--;
80      i--;
81    }
82  }
83}
84
85void drawBlips() {
86  unsigned long currentTime = millis();
87  for (int i = 0; i < blipCount; i++) {
88    if (blips[i].active) {
89      float age = (currentTime - blips[i].timestamp) / (float)fadeTime;
90      int alpha = 255 * (1.0 - age); // Fade effect
91      int x = centerX + (blips[i].distance * maxRadius / maxDistance) * cos(radians(blips[i].angle));
92      int y = centerY - (blips[i].distance * maxRadius / maxDistance) * sin(radians(blips[i].angle));
93      
94      if (age < 0.5) {
95        
96        display.drawLine(x-2, y-2, x+2, y+2, SSD1306_WHITE);
97        display.drawLine(x-2, y+2, x+2, y-2, SSD1306_WHITE);
98      } else {
99        
100        display.drawPixel(x, y, SSD1306_WHITE);
101      }
102    }
103  }
104}
105
106void drawRadar() {
107  
108  display.drawCircle(centerX, centerY, maxRadius / 2, SSD1306_WHITE);
109  display.drawCircle(centerX, centerY, maxRadius, SSD1306_WHITE);
110}
111
112void loop() {
113  static int angle = 0;
114  static bool forward = true;
115  static unsigned long lastServoMove = 0;
116  static unsigned long lastMeasurement = 0;
117
118  unsigned long currentTime = millis();
119
120  
121  if (currentTime - lastServoMove >= 25) {
122    servo.write(angle);
123    if (forward) {
124      angle += 2;
125      if (angle >= 180) {
126        angle = 180; // Ensure exact boundary
127        forward = false;
128      }
129    } else {
130      angle -= 2;
131      if (angle <= 0) {
132        angle = 0; // Ensure exact boundary
133        forward = true;
134      }
135    }
136    lastServoMove = currentTime;
137  }
138
139  
140  if (currentTime - lastMeasurement >= 100) {
141    float distance = measureDistance();
142    if (distance < maxDistance) {
143      addBlip(angle, (int)distance);
144    }
145    lastMeasurement = currentTime;
146  }
147
148  
149  if (currentTime - lastUpdate >= 33) {
150    display.clearDisplay();
151    updateBlips();
152    drawRadar();
153    
154    // Draw sweep line
155    int sweepX = centerX + maxRadius * cos(radians(angle));
156    int sweepY = centerY - maxRadius * sin(radians(angle));
157    display.drawLine(centerX, centerY, sweepX, sweepY, SSD1306_WHITE);
158    
159    drawBlips();
160    display.display();
161    lastUpdate = currentTime;
162  }
163}