International Space Station Tracker With Map Visuals

ISS Tracker is an embedded systems project built around the ESP32 that provides real-time tracking of the International Space Station as it orbits Earth at over 27,000 km/h. The device connects to the internet via Wi-Fi, periodically fetching live orbital data from a public API and translating raw coordinates into a meaningful visual representation. The ISS’s current latitude and longitude are plotted on a world map rendered on an OLED display, allowing users to see its position relative to the planet at a glance.

Alongside the graphical view, a 16×2 I²C LCD presents clear textual information such as coordinates, connection status, and system messages, ensuring readability even from a distance. An onboard buzzer adds audible feedback for key events, enhancing interactivity without overcomplicating the design. Beyond tracking the ISS itself, the project serves as a practical demonstration of real-world IoT concepts, including wireless networking, API consumption, data parsing, and multi-display coordination on a resource-constrained microcontroller. The ISS Tracker is intended as both an educational tool and a foundation for further experimentation in embedded networking and space-related visualization.

Component List

ESP32 38P Type-C CP2102

1. Description: A versatile micro-controller with Wi-Fi and Bluetooth capabilities, used for processing and controlling the circuit.
2. Pins: 5V, CMD, SD3, SD2, G13, GND, G12, G14, G27, G26, G25, G23, G32, G35, G34, SN, SP, EN, 3V3, CLK, SD0, SD1, G15, G2, G0, G4, G16, G17, G5, G18, G19, G21, RXD, TXD, G22

OLED Display

1. Description: A small, efficient display used for visual output, connected via I2C.
2. Pins: GND, VCC, SCL, SDA

LCD 16x2 Attached I2C

1. Description: A 16x2 character display module with I2C interface, used for displaying text.
2. Pins: GND, VCC, SDA, SCL

Component List (yeah its the same thing, just check it guys)

ESP32 38P Type-C CP2102

1. Description: A versatile microcontroller with Wi-Fi and Bluetooth capabilities, used for processing and controlling the circuit.
2. Pins: 5V, CMD, SD3, SD2, G13, GND, G12, G14, G27, G26, G25, G23, G32, G35, G34, SN, SP, EN, 3V3, CLK, SD0, SD1, G15, G2, G0, G4, G16, G17, G5, G18, G19, G21, RXD, TXD, G22

OLED Display

1. Description: A small, efficient display used for visual output, connected via I2C.
2. Pins: GND, VCC, SCL, SDA

LCD 16x2 Attached I2C

1. Description: A 16x2 character display module with I2C interface, used for displaying text.
2. Pins: GND, VCC, SDA, SCL

Bread Board or Proto-board

1. Description: To make connections. Either directly put it on breadboard or solder on protoboard for more permanent model.

You are good to go...

Wiring Details (make sure its correct)

ESP32 38P Type-C CP2102

1. G21: Connected to SDA of both OLED and LCD 16x2.
2. G22: Connected to SCL of both OLED and LCD 16x2.
3. 3V3: Connected to VCC of OLED.
4. 5V: Connected to VCC of LCD 16x2.
5. GND: Connected to GND of both OLED and LCD 16x2.

OLED Display

1. SDA: Connected to G21 of ESP32.
2. SCL: Connected to G22 of ESP32.
3. VCC: Connected to 3V3 of ESP32.
4. GND: Connected to GND of ESP32.

LCD 16x2 Attached I2C

1. SDA: Connected to G21 of ESP32.
2. SCL: Connected to G22 of ESP32.
3. VCC: Connected to 5V of ESP32.
4. GND: Connected to GND of ESP32

Note: Yeah lcd and oled sda and scl are on same pins cause they get different addresses so, all of this works out.

Soldering is better option ngl.

CODE:

#include <WiFi.h>

#include <HTTPClient.h>

#include <Arduino_JSON.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#include <LiquidCrystal_I2C.h>

// ========== CONFIG ==========

#define SCREEN_WIDTH 128

#define SCREEN_HEIGHT 64

#define BUZZER_PIN 15

#define ISS_UPDATE_INTERVAL 5000 // 5 sec (balance between API limits & freshness)

#define DISPLAY_UPDATE_INTERVAL 500 // 500ms for smooth visuals

#define DOT_BLINK_SPEED 600

#define BUZZER_INTERVAL 500

// WiFi Credentials (consider using NVS for flexibility)

const char* SSID = "wifi ssid/name";

const char* PASSWORD = "wifi password";

const char* ISS_API = "http://api.open-notify.org/iss-now.json";

// ========== DISPLAY OBJECTS ==========

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

LiquidCrystal_I2C lcd(0x27, 16, 2);

// ========== WORLD MAP BITMAP ==========

const unsigned char worldMap[] PROGMEM = {

0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0xfe, 0x7f, 0x0f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0x80, 0x80, 0x07, 0xfc, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xbf, 0x4e, 0x00, 0x07, 0xff, 0xff, 0xef, 0xfc, 0x3f, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xfc, 0x7b, 0xbf, 0xc0, 0x0f, 0xff, 0xff, 0xdf, 0xc0, 0x0d, 0xff, 0xff, 0xff, 0xff,

0xff, 0xcf, 0xfe, 0x1b, 0x07, 0xc0, 0x1f, 0xff, 0xff, 0xfc, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff,

0xfe, 0x00, 0x00, 0xb0, 0x63, 0xc0, 0xff, 0xfe, 0x03, 0x80, 0x80, 0x00, 0x00, 0x00, 0x1f, 0xff,

0xf8, 0x00, 0x10, 0x01, 0xc3, 0x87, 0xe7, 0xfc, 0x46, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0xff,

0xf0, 0x00, 0x00, 0x0f, 0xef, 0x8f, 0xff, 0xf0, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0xff,

0xe0, 0x80, 0x00, 0x3f, 0x3f, 0xdf, 0xff, 0xf0, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x03, 0x3f, 0xff,

0xf7, 0xf0, 0x00, 0x3e, 0x0f, 0xff, 0xff, 0x7d, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x3f, 0x7f, 0xff,

0xff, 0xe0, 0x00, 0x0e, 0x0f, 0xff, 0xff, 0x7f, 0x80, 0x00, 0x00, 0x00, 0x00, 0x7f, 0x3f, 0xff,

0xff, 0xe0, 0x02, 0x08, 0x07, 0xff, 0xfd, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0f, 0xbf, 0xff,

0xff, 0xe0, 0x00, 0x00, 0x07, 0xff, 0xff, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff,

0xff, 0xf0, 0x00, 0x80, 0x77, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xff, 0xff,

0xff, 0xe0, 0x00, 0x40, 0x7f, 0xff, 0xff, 0x80, 0x01, 0x08, 0x04, 0x00, 0x00, 0x07, 0xff, 0xff,

0xff, 0xc0, 0x00, 0x81, 0xff, 0xff, 0xff, 0x8a, 0x0f, 0x18, 0x00, 0x00, 0x00, 0x06, 0xff, 0xff,

0xff, 0x80, 0x00, 0x03, 0xff, 0xff, 0xfc, 0x3d, 0x8d, 0x88, 0x00, 0x00, 0x00, 0x1f, 0xff, 0xff,

0xff, 0x80, 0x00, 0x0f, 0xff, 0xff, 0xfc, 0x7e, 0xb0, 0x0c, 0x00, 0x00, 0x01, 0xdf, 0x7f, 0xff,

0xff, 0x80, 0x00, 0x1f, 0xff, 0xff, 0xfc, 0xfd, 0xf0, 0x04, 0x00, 0x00, 0x00, 0x6e, 0x7f, 0xff,

0xff, 0x80, 0x00, 0x1f, 0xff, 0xff, 0xfe, 0x07, 0xfe, 0x00, 0x00, 0x00, 0x00, 0x6c, 0xff, 0xff,

0xff, 0xc0, 0x00, 0x7f, 0xff, 0xff, 0xf8, 0x01, 0xbe, 0x00, 0x00, 0x00, 0x00, 0x3b, 0xff, 0xff,

0xff, 0xc0, 0x04, 0xff, 0xff, 0xff, 0xf8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff,

0xff, 0xd0, 0x3e, 0xff, 0xff, 0xff, 0xf0, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x3f, 0xff, 0xff,

0xff, 0xf0, 0x7f, 0xff, 0xff, 0xff, 0xe0, 0x00, 0x01, 0x03, 0x80, 0x00, 0x00, 0x3f, 0xff, 0xff,

0xff, 0xf8, 0x7f, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x80, 0x78, 0x00, 0x00, 0x5f, 0xff, 0xff,

0xff, 0xf8, 0x77, 0x7f, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x80, 0x7c, 0x06, 0x01, 0xff, 0xff, 0xff,

0xff, 0xfc, 0x67, 0xef, 0xff, 0xff, 0xc0, 0x00, 0x00, 0xc0, 0x7e, 0x0f, 0x05, 0xff, 0xff, 0xff,

0xff, 0xfe, 0x0f, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x61, 0xfe, 0x1f, 0x03, 0xef, 0xff, 0xff,

0xff, 0xff, 0xc3, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x23, 0xff, 0x3f, 0xc3, 0xef, 0xff, 0xff,

0xff, 0xff, 0xf3, 0xff, 0xff, 0xff, 0xc0, 0x00, 0x00, 0x1f, 0xff, 0x3f, 0xd1, 0xff, 0xff, 0xff,

0xff, 0xff, 0xfb, 0x81, 0xff, 0xff, 0xe0, 0x00, 0x00, 0x03, 0xff, 0xbf, 0xfb, 0xff, 0xff, 0xff,

0xff, 0xff, 0xfd, 0x00, 0xff, 0xff, 0xf0, 0x00, 0x00, 0x03, 0xff, 0xdf, 0xdf, 0xfb, 0xff, 0xff,

0xff, 0xff, 0xff, 0x00, 0x3f, 0xff, 0xf8, 0x60, 0x00, 0x07, 0xff, 0xff, 0xef, 0xdf, 0xff, 0xff,

0xff, 0xff, 0xff, 0x00, 0x1f, 0xff, 0xff, 0xf8, 0x00, 0x07, 0xff, 0xff, 0xd7, 0x3f, 0xff, 0xff,

0xff, 0xff, 0xfe, 0x00, 0x0f, 0xff, 0xff, 0xf8, 0x00, 0x1f, 0xff, 0xff, 0xce, 0x1f, 0xff, 0xff,

0xff, 0xff, 0xfe, 0x00, 0x07, 0xff, 0xff, 0xf8, 0x02, 0x1f, 0xff, 0xff, 0xe6, 0x3f, 0x7f, 0xff,

0xff, 0xff, 0xfe, 0x00, 0x00, 0xff, 0xff, 0xf8, 0x00, 0x3f, 0xff, 0xff, 0xf3, 0x2f, 0x87, 0xff,

0xff, 0xff, 0xfe, 0x00, 0x00, 0x3f, 0xff, 0xfc, 0x00, 0x7f, 0xff, 0xff, 0xfb, 0xff, 0xe1, 0xff,

0xff, 0xff, 0xff, 0x00, 0x00, 0x3f, 0xff, 0xfc, 0x00, 0x7f, 0xff, 0xff, 0xfc, 0x7f, 0xe1, 0xff,

0xff, 0xff, 0xff, 0x00, 0x00, 0x3f, 0xff, 0xfc, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xff,

0xff, 0xff, 0xff, 0x80, 0x00, 0x7f, 0xff, 0xfe, 0x00, 0x3f, 0xff, 0xff, 0xff, 0xff, 0x37, 0xff,

0xff, 0xff, 0xff, 0x80, 0x00, 0x7f, 0xff, 0xfc, 0x00, 0x3b, 0xff, 0xff, 0xff, 0xfa, 0x37, 0xff,

0xff, 0xff, 0xff, 0xe0, 0x00, 0x7f, 0xff, 0xfc, 0x00, 0x63, 0xff, 0xff, 0xff, 0xf0, 0x13, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x00, 0xff, 0xff, 0xfc, 0x00, 0xe7, 0xff, 0xff, 0xff, 0xe0, 0x03, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x00, 0xff, 0xff, 0xfe, 0x01, 0xe7, 0xff, 0xff, 0xff, 0x80, 0x01, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x03, 0xff, 0xff, 0xfe, 0x00, 0xe7, 0xff, 0xff, 0xff, 0x00, 0x01, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x07, 0xff, 0xff, 0xfe, 0x01, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x07, 0xff, 0xff, 0xfe, 0x03, 0xff, 0xff, 0xff, 0xfe, 0x00, 0x00, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x07, 0xff, 0xff, 0xff, 0x07, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x0f, 0xff, 0xff, 0xff, 0x07, 0xff, 0xff, 0xff, 0xfe, 0x1e, 0x03, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xff, 0x07, 0xff,

0xff, 0xff, 0xff, 0xf0, 0x1f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x0f, 0xff,

0xff, 0xff, 0xff, 0xf8, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfb,

0xff, 0xff, 0xff, 0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf, 0xef,

0xff, 0xff, 0xff, 0xf8, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x9f,

0xff, 0xff, 0xff, 0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f,

0xff, 0xff, 0xff, 0xfc, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xfe, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,

0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff

};

// ========== GLOBAL STATE ==========

struct ISSData {

float latitude;

float longitude;

unsigned long lastUpdate;

bool isValid;

} issData = {0, 0, 0, false};

unsigned long prevISS = 0;

unsigned long prevDisplay = 0;

unsigned long prevBuzz = 0;

bool dotVisible = true;

bool wifiConnected = false;

// ========== FUNCTION DECLARATIONS ==========

void initHardware();

void showIntro();

void connectWiFi();

void updateISS();

void drawISS(float lat, float lon);

void updateLCD(float lat, float lon);

void handleBuzzer();

// ========== SETUP ==========

void setup() {

Serial.begin(115200);

delay(500);

initHardware();

showIntro();

connectWiFi();

}

// ========== LOOP ==========

void loop() {

unsigned long now = millis();

// Update ISS data every interval

if (now - prevISS >= ISS_UPDATE_INTERVAL) {

prevISS = now;

updateISS();

}

// Update displays only when needed (not every millisecond)

if (now - prevDisplay >= DISPLAY_UPDATE_INTERVAL) {

prevDisplay = now;

if (issData.isValid) {

drawISS(issData.latitude, issData.longitude);

updateLCD(issData.latitude, issData.longitude);

}

}

// Handle buzzer with timing

handleBuzzer();

delay(10); // Prevent watchdog issues

}

// ========== HARDWARE INITIALIZATION ==========

void initHardware() {

lcd.init();

lcd.backlight();

if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {

Serial.println("OLED init failed!");

while (1);

}

pinMode(BUZZER_PIN, OUTPUT);

digitalWrite(BUZZER_PIN, LOW);

}

// ========== INTRO SCREEN ==========

void showIntro() {

display.clearDisplay();

display.setTextSize(2);

display.setTextColor(WHITE);

display.setCursor(15, 10);

display.println("ISS");

display.setCursor(10, 30);

display.println("TRACKER");

display.setTextSize(1);

display.setCursor(25, 55);

display.println("Initializing...");

display.display();

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("ISS Tracker");

lcd.setCursor(0, 1);

lcd.print("Initializing...");

delay(2000);

}

// ========== WIFI CONNECTION ==========

void connectWiFi() {

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("WiFi: Connecting");

// Disable power saving for more reliable connection

WiFi.setSleep(false);

WiFi.mode(WIFI_STA);

WiFi.disconnect(true); // Turn off WiFi first

delay(500);

Serial.println("\n--- WiFi Debug Info ---");

Serial.printf("SSID: %s\n", SSID);

Serial.printf("Signal Strength: %d\n", WiFi.RSSI());

WiFi.begin(SSID, PASSWORD);

int attempts = 0;

while (WiFi.status() != WL_CONNECTED && attempts < 30) {

delay(400);

Serial.printf("Attempt %d, Status: %d\n", attempts, WiFi.status());

lcd.setCursor(attempts % 16, 1);

lcd.print(".");

attempts++;

}

if (WiFi.status() == WL_CONNECTED) {

wifiConnected = true;

String ip = WiFi.localIP().toString();

Serial.println("\n--- WiFi Connected ---");

Serial.printf("IP: %s\n", ip.c_str());

Serial.printf("RSSI: %d\n", WiFi.RSSI());

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("WiFi: OK");

lcd.setCursor(0, 1);

lcd.print(ip.c_str());

delay(2000);

} else {

Serial.println("WiFi connection failed!");

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("WiFi: Failed");

lcd.setCursor(0, 1);

lcd.print("Retry in 10s");

wifiConnected = false;

delay(10000);

connectWiFi(); // Retry

}

}

// ========== UPDATE ISS POSITION ==========

void updateISS() {

if (WiFi.status() != WL_CONNECTED) {

wifiConnected = false;

issData.isValid = false;

Serial.println("WiFi not connected");

return;

}

HTTPClient http;

http.setTimeout(8000);

http.setConnectTimeout(8000);

// Use HTTP (not HTTPS) - simpler, faster

bool httpBegin = http.begin("http://api.open-notify.org/iss-now.json");

if (!httpBegin) {

Serial.println("HTTP begin failed");

issData.isValid = false;

http.end();

return;

}

// Add headers

http.addHeader("Connection", "close");

http.addHeader("User-Agent", "ESP32-ISS-Tracker");

Serial.println("Sending HTTP request...");

int httpCode = http.GET();

if (httpCode > 0) {

Serial.printf("HTTP Code: %d\n", httpCode);

if (httpCode == HTTP_CODE_OK || httpCode == 200) {

String payload = http.getString();

Serial.printf("Payload length: %d\n", payload.length());

Serial.printf("Payload: %.100s\n", payload.c_str());

JSONVar obj = JSON.parse(payload);

if (obj.hasOwnProperty("iss_position")) {

const char* latPtr = (const char*)obj["iss_position"]["latitude"];

const char* lonPtr = (const char*)obj["iss_position"]["longitude"];

if (latPtr && lonPtr) {

issData.latitude = atof(latPtr);

issData.longitude = atof(lonPtr);

issData.lastUpdate = millis();

issData.isValid = true;

Serial.printf("✓ ISS: %.2f, %.2f\n", issData.latitude, issData.longitude);

} else {

Serial.println("Latitude/Longitude missing");

issData.isValid = false;

}

}

} else {

Serial.println("JSON parse failed");

issData.isValid = false;

}

} else {

Serial.printf("HTTP Error: %d\n", httpCode);

issData.isValid = false;

}

http.end();

}

// ========== DRAW ISS ON OLED ==========

void drawISS(float lat, float lon) {

display.clearDisplay();

display.drawBitmap(0, 0, worldMap, 128, 64, WHITE);

// Map coordinates to pixel location

int x = map(lon, -180, 180, 0, 128);

int y = map(lat, 90, -90, 0, 64);

// Clamp values to screen bounds

x = constrain(x, 0, 127);

y = constrain(y, 0, 63);

// Blinking effect

static unsigned long lastBlink = 0;

if (millis() - lastBlink > DOT_BLINK_SPEED) {

lastBlink = millis();

dotVisible = !dotVisible;

}

if (dotVisible) {

display.fillCircle(x, y, 2, WHITE);

}

// Display timestamp

display.setTextSize(1);

display.setTextColor(WHITE);

display.setCursor(0, 0);

display.printf("Update: %lus ago", (millis() - issData.lastUpdate) / 1000);

display.display();

}

// ========== UPDATE LCD DISPLAY ==========

void updateLCD(float lat, float lon) {

static float prevLat = 0;

static float prevLon = 0;

// Only update if values changed significantly (>0.1 degrees)

if (fabs(lat - prevLat) > 0.1 || fabs(lon - prevLon) > 0.1) {

prevLat = lat;

prevLon = lon;

lcd.clear();

lcd.setCursor(0, 0);

lcd.print("LAT:");

lcd.print(lat, 2);

lcd.setCursor(0, 1);

lcd.print("LON:");

lcd.print(lon, 2);

}

}

// ========== BUZZER CONTROL ==========

void handleBuzzer() {

static unsigned long lastBuzzToggle = 0;

if (millis() - lastBuzzToggle >= BUZZER_INTERVAL) {

lastBuzzToggle = millis();

static bool buzzing = false;

buzzing = !buzzing;

if (buzzing && issData.isValid) {

tone(BUZZER_PIN, 1200, BUZZER_INTERVAL - 50);

} else {

noTone(BUZZER_PIN);

}

}

}

Enjoy!