ESP32 - Smart Weather Station
This tutorial instructs you how to turn an ESP32 and a 1.28 inch round TFT LCD display into a smart weather station that reads live weather from the Internet instead of from a sensor.
Here is what you will learn:
- How to wire the round GC9A01 TFT LCD and a push button to an ESP32
- How to make a secure HTTPS call to the Open-Meteo weather API
- How to read the JSON answer with the ArduinoJson library
- How to sync the ESP32 clock over NTP
- How to paint eight circular pages and move between them with one button
Because the ESP32 has WiFi built in, no extra network module is needed. The weather comes from a web service, so the station can also show values that a cheap sensor cannot measure, such as the rain chance for the next hours and the forecast for the next three days.
Hardware Used In This Tutorial
| 1 | × | ESP32 Development Board | |
| 1 | × | Micro USB Cable | |
| 1 | × | 1.28 Inch Round Circular TFT LCD Display Module | |
| 1 | × | Push Button | |
| 1 | × | Button Module Alternatively, | |
| 1 | × | Breadboard | |
| 1 | × | Jumper Wires |
Only one of the two button parts is required. Both options are wired below.
| 1 | × | Recommended: Screw Terminal Expansion Board for ESP32 | |
| 1 | × | Recommended: Breakout Expansion Board for ESP32 | |
| 1 | × | Recommended: Power Splitter for ESP32 |
Or you can buy the following kits:
| 1 | × | DIYables ESP32 Starter Kit (ESP32 included) | |
| 1 | × | DIYables ESP32 S3 Starter Kit (ESP32 S3 included) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
Disclosure: Some of the links in this section are Amazon affiliate links, meaning we may earn a commission at no additional cost to you if you make a purchase through them. Additionally, some links direct you to products from our own brand, DIYables .
Introduction to the Weather Station Pages
The station holds eight pages. A single push button walks through them:
| Page | What it shows |
|---|---|
| HOME | Weather icon, temperature, sky description, and an NTP clock |
| TEMP | Temperature and the apparent "feels like" temperature |
| HUMIDITY | Humidity drawn as a ring plus the exact percentage |
| WIND | Wind speed and wind direction on a compass rose |
| RAIN | Rain chance with an animated rain effect |
| NEXT HOURS | Temperature and rain chance hour by hour |
| FORECAST | Highest and lowest temperature for the next 3 days |
| SYSTEM | WiFi state, signal strength, API state, and location |
The ESP32 refreshes the weather every 10 minutes. Between two refreshes the clock on the home page keeps ticking, because the ESP32 keeps its own time after the NTP sync.
Introduction to the Open-Meteo Weather API
Open-Meteo supplies the weather data. It suits an ESP32 project well:
| Open-Meteo | |
|---|---|
| The API key | not required, no sign-up |
| The cost | free for personal use |
| The answer format | plain JSON |
| The place | chosen by latitude and longitude |
| The protocol | HTTPS on port 443 |
One request returns the weather now, the hourly values for the next days, and a three-day daily summary. The timezone parameter makes the service return local times rather than UTC.
Wiring Diagram
The display talks over the default hardware SPI bus of the ESP32, so GPIO18 and GPIO23 are fixed.
| TFT LCD Pin | ESP32 | Description |
|---|---|---|
| VCC | 3.3V | Power supply |
| GND | GND | Ground |
| SCL | GPIO18 | SPI Clock (fixed) |
| SDA | GPIO23 | SPI MOSI (fixed) |
| DC | GPIO25 | Data/Command |
| CS | GPIO26 | Chip Select |
| RST | GPIO27 | Reset |
The button input on GPIO16 accepts either a bare push button or a ready-made button module. Wire whichever part you own, then match the code to it.
※ NOTE THAT:
GPIO16 is a plain input pin on the ESP32-WROOM-32 board used here. It is not a strapping pin and it has a working internal pull-up.
One exception is worth knowing: on ESP32-WROVER modules, which carry PSRAM, GPIO16 and GPIO17 are wired to the PSRAM chip and cannot be used. If your board has PSRAM, move the button to another free pin, for example GPIO22, and change PIN_BUTTON in the code to match.
Option 1: Bare Push Button
A push button carries no resistor of its own. One leg goes to GPIO16, the other to ground, and the ESP32 supplies the pull-up internally. The pin therefore sits HIGH and falls to LOW while the button is held.
This image is created using Fritzing. Click to enlarge image
| Button Pin | ESP32 | Description |
|---|---|---|
| Pin 1 | GPIO16 | Button input, internal pull-up |
| Pin 2 | GND | Ground |
The sketch ships configured for this option:
ezButton button(PIN_BUTTON);
Option 2: Button Module
A button module carries a pull-down resistor on its own board and needs a supply rail. Its OUT pin rests at LOW and rises to HIGH on a press, which is the opposite of the bare button.
This image is created using Fritzing. Click to enlarge image
| Button Module Pin | ESP32 | Description |
|---|---|---|
| VCC | 3.3V | Power supply |
| GND | GND | Ground |
| OUT | GPIO16 | Signal, LOW at rest, HIGH when pressed |
Because the module brings its own resistor, the internal one has to stay off. One line changes:
ezButton button(PIN_BUTTON, EXTERNAL_PULLDOWN);
※ NOTE THAT:
Power the display from 3.3V. The GC9A01 module tolerates 5V on many boards, but 3.3V matches the ESP32 logic level and is the safer choice.
If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: The best way to Power ESP32 and sensors/displays.
How To Program ESP32 for the Weather Station
Pull in the libraries. WiFi.h, WiFiClientSecure.h, HTTPClient.h, and time.h all ship with the ESP32 core, so only ArduinoJson, DIYables_TFT_Round, and ezButton come from the Library Manager.
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <time.h>
#include <DIYables_TFT_Round.h>
#include <ezButton.h>
Build the display object from the reset, data/command, and chip select pins.
DIYables_TFT_GC9A01_Round tft(27, 25, 26);
Fill in the WiFi details and the place you want to watch.
#define WIFI_SSID "YOUR_WIFI_SSID"
#define WIFI_PASSWORD "YOUR_WIFI_PASSWORD"
#define LATITUDE 37.5665
#define LONGITUDE 126.9780
Join the network.
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
Sync the clock over NTP. GMT_OFFSET_SEC carries the offset from UTC in seconds.
configTime(GMT_OFFSET_SEC, DST_OFFSET_SEC, "pool.ntp.org", "time.nist.gov");
struct tm timeinfo;
getLocalTime(&timeinfo, 10000);
Open a secure connection and fire the request. setInsecure() skips certificate checking, which keeps the sketch short for a prototype.
WiFiClientSecure client;
client.setInsecure();
HTTPClient http;
http.begin(client, url);
int httpCode = http.GET();
String payload = http.getString();
Hand the answer to ArduinoJson and pick out a value.
JsonDocument doc;
deserializeJson(doc, payload);
float temperature = doc["current"]["temperature_2m"] | 0.0;
Paint it on the round screen.
tft.setTextSize(3);
tft.setTextColor(DIYables_TFT::colorRGB(255, 255, 255));
tft.setCursor(80, 100);
tft.print(temperature, 1);
ESP32 Code - Smart Weather Station
/*
* This ESP32 code is created by esp32io.com
*
* This ESP32 code is released in the public domain
*
* For more detail (instruction and wiring diagram), visit https://esp32io.com/tutorials/esp32-smart-weather-station
*/
/*
============================================================
SMART WEATHER STATION
ESP32 + GC9A01 Round TFT + Push Button
Location:
Seoul, South Korea (change it in USER CONFIGURATION)
Weather API:
Open-Meteo (free, no API key needed)
------------------------------------------------------------
GC9A01 Round TFT -> ESP32
VCC -> 3.3V
GND -> GND
SCL -> GPIO18 (hardware SPI clock, fixed)
SDA -> GPIO23 (hardware SPI MOSI, fixed)
RST -> GPIO27
DC -> GPIO25
CS -> GPIO26
Button
GPIO16 -> BUTTON -> GND
------------------------------------------------------------
BUTTON
Short press -> Next page
Long press -> Refresh weather
Very long press -> Back to home page
============================================================
*/
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <time.h>
#include <DIYables_TFT_Round.h>
#include <ezButton.h>
// ===== USER CONFIGURATION =====
#define WIFI_SSID "YOUR_WIFI_SSID"
#define WIFI_PASSWORD "YOUR_WIFI_PASSWORD"
#define LATITUDE 37.5665
#define LONGITUDE 126.9780
#define LOCATION_NAME "SEOUL"
// Time zone name for the API, URL-encoded.
// "/" must be written as "%2F".
#define TIMEZONE "Asia%2FSeoul"
// Offset from UTC in seconds, used by the NTP clock.
// Seoul is UTC+9, so 9 * 3600.
#define GMT_OFFSET_SEC (9 * 3600)
// Extra offset for summer time. Use 3600 where it applies.
#define DST_OFFSET_SEC 0
// ===== PIN CONFIGURATION =====
// SCK (GPIO18) and MOSI (GPIO23) are the hardware SPI pins of
// the ESP32. The library uses them on its own, so they are not
// listed here.
#define PIN_BUTTON 16
#define PIN_RST 27
#define PIN_DC 25
#define PIN_CS 26
// ===== TIMING =====
const unsigned long API_UPDATE_INTERVAL = 10UL * 60UL * 1000UL;
const unsigned long WIFI_RETRY_INTERVAL = 10UL * 1000UL;
const unsigned long WIFI_CONNECT_TIMEOUT = 15UL * 1000UL;
const unsigned long BUTTON_DEBOUNCE = 40;
const unsigned long LONG_PRESS_TIME = 600;
const unsigned long VERY_LONG_PRESS_TIME = 2000;
const unsigned long RAIN_ANIMATION_INTERVAL = 90;
const unsigned long CLOCK_UPDATE_INTERVAL = 1000;
// ===== TFT =====
DIYables_TFT_GC9A01_Round tft(PIN_RST, PIN_DC, PIN_CS);
// ===== SCREEN =====
const int SCREEN_W = 240;
const int SCREEN_H = 240;
const int CENTER_X = 120;
const int CENTER_Y = 120;
// ===== COLORS =====
#define BLACK DIYables_TFT::colorRGB(0, 0, 0)
#define WHITE DIYables_TFT::colorRGB(255, 255, 255)
#define CYAN DIYables_TFT::colorRGB(0, 220, 255)
#define BLUE DIYables_TFT::colorRGB(40, 120, 255)
#define LIGHT_BLUE DIYables_TFT::colorRGB(90, 190, 255)
#define GREEN DIYables_TFT::colorRGB(60, 230, 130)
#define YELLOW DIYables_TFT::colorRGB(255, 210, 60)
#define ORANGE DIYables_TFT::colorRGB(255, 150, 40)
#define RED DIYables_TFT::colorRGB(255, 70, 70)
#define PURPLE DIYables_TFT::colorRGB(180, 100, 255)
#define GRAY DIYables_TFT::colorRGB(125, 125, 135)
#define DARK_GRAY DIYables_TFT::colorRGB(42, 42, 52)
#define DARK_BLUE DIYables_TFT::colorRGB(12, 18, 48)
// ===== PAGE =====
enum Page {
PAGE_HOME = 0,
PAGE_TEMP,
PAGE_HUMIDITY,
PAGE_WIND,
PAGE_RAIN,
PAGE_HOURLY,
PAGE_FORECAST,
PAGE_SYSTEM,
PAGE_COUNT
};
Page currentPage = PAGE_HOME;
// ===== WEATHER DATA =====
struct WeatherData {
bool valid = false;
float temperature = 0;
float humidity = 0;
float feelsLike = 0;
float windSpeed = 0;
float windDirection = 0;
float pressure = 0;
int weatherCode = 0;
bool isDay = true;
int currentRainChance = 0;
float uvIndex = 0;
String sunrise;
String sunset;
// NEXT HOURS
float hourlyTemp[12];
int hourlyRainChance[12];
int hourlyWeatherCode[12];
String hourlyTime[12];
// DAILY
String dailyDate[3];
float dailyTempMax[3];
float dailyTempMin[3];
int dailyRainChance[3];
int dailyWeatherCode[3];
float dailyUV[3];
};
WeatherData weather;
// ===== SYSTEM STATE =====
bool apiOnline = false;
bool wifiOnline = false;
bool screenDirty = true;
bool isFetching = false;
bool pendingRefresh = false;
unsigned long lastApiUpdate = 0;
unsigned long lastWifiRetry = 0;
unsigned long wifiConnectStart = 0;
unsigned long lastRainAnimation = 0;
unsigned long lastClockUpdate = 0;
bool wifiConnecting = false;
// ===== BUTTON =====
// ezButton handles the debouncing, so the sketch only has to
// measure how long the button was held down.
//
// The line below is for a BARE push button wired to GND. ezButton then
// uses the internal pull-up resistor of the board, and the pin reads LOW
// while the button is held down.
ezButton button(PIN_BUTTON);
// If you use a BUTTON MODULE instead, the module carries its own resistor
// on the board, so the internal one must not be used. Comment the line
// above and use this line instead:
// ezButton button(PIN_BUTTON, EXTERNAL_PULLDOWN);
unsigned long buttonPressStart = 0;
// ===== RAIN ANIMATION =====
const int RAIN_DROP_COUNT = 16;
int rainX[RAIN_DROP_COUNT];
int rainY[RAIN_DROP_COUNT];
bool rainInitialized = false;
const int RAIN_AREA_X = 30;
const int RAIN_AREA_Y = 125;
const int RAIN_AREA_W = 180;
const int RAIN_AREA_H = 78;
// ===== WEATHER DESCRIPTION =====
String weatherDescription(int code) {
switch (code) {
case 0:
return "CLEAR";
case 1:
return "MAINLY CLEAR";
case 2:
return "PARTLY CLOUDY";
case 3:
return "OVERCAST";
case 45:
case 48:
return "FOG";
case 51:
case 53:
case 55:
return "DRIZZLE";
case 56:
case 57:
return "FREEZING DRIZZLE";
case 61:
case 63:
case 65:
return "RAIN";
case 66:
case 67:
return "FREEZING RAIN";
case 71:
case 73:
case 75:
return "SNOW";
case 77:
return "SNOW GRAINS";
case 80:
case 81:
case 82:
return "SHOWERS";
case 85:
case 86:
return "SNOW SHOWERS";
case 95:
return "THUNDERSTORM";
case 96:
case 99:
return "STORM";
default:
return "UNKNOWN";
}
}
// ===== WEATHER COLOR =====
uint16_t weatherColor(int code) {
if (code == 0) return YELLOW;
if (code == 1 || code == 2) return CYAN;
if (code == 3) return GRAY;
if (code >= 51 && code <= 67) return BLUE;
if (code >= 80 && code <= 82) return LIGHT_BLUE;
if (code >= 95) return RED;
return WHITE;
}
// ===== WIND DIRECTION =====
String windDirectionText(float degrees) {
const char* directions[] = {
"N",
"NE",
"E",
"SE",
"S",
"SW",
"W",
"NW"
};
int index = (int)((degrees + 22.5) / 45.0);
index %= 8;
return directions[index];
}
// ===== CENTER TEXT =====
void drawCenteredText(String text, int y, int size, uint16_t color) {
tft.setTextSize(size);
tft.setTextColor(color);
int width = text.length() * 6 * size;
int x = CENTER_X - width / 2;
if (x < 0) x = 0;
tft.setCursor(x, y);
tft.print(text);
}
// ===== HEADER =====
void drawHeader(String title, uint16_t color) {
// Safe radius from screen center (slightly less than the
// physical 120px radius, to keep a small margin from the
// round bezel).
const float SAFE_RADIUS = 116.0;
int size = 2;
int width = title.length() * 6 * size;
int half = width / 2;
int y;
if (half >= SAFE_RADIUS) {
// Too wide even at the lowest safe position -> use a
// smaller font instead of clipping.
size = 1;
width = title.length() * 6 * size;
half = width / 2;
y = 14;
} else {
// Compute the minimum y (top of text) so the top corners
// of the text stay inside the round visible area.
float insideSpan = sqrt((SAFE_RADIUS * SAFE_RADIUS) - ((float)half * (float)half));
int minY = (int)(120.0 - insideSpan);
y = (minY > 14) ? minY : 14;
}
drawCenteredText(title, y, size, color);
int lineY = y + (size == 2 ? 16 : 8) + 6;
tft.drawLine(45, lineY, 195, lineY, DARK_GRAY);
}
// ===== FOOTER =====
void drawFooter() {
tft.drawLine(55, 214, 185, 214, DARK_GRAY);
drawCenteredText(String(currentPage + 1) + "/" + String(PAGE_COUNT), 220, 1, GRAY);
}
// ===== SUN ICON =====
void drawSun(int x, int y, int radius) {
tft.fillCircle(x, y, radius, YELLOW);
for (int i = 0; i < 8; i++) {
float angle = i * PI / 4.0;
int x1 = x + cos(angle) * (radius + 7);
int y1 = y + sin(angle) * (radius + 7);
int x2 = x + cos(angle) * (radius + 14);
int y2 = y + sin(angle) * (radius + 14);
tft.drawLine(x1, y1, x2, y2, YELLOW);
}
}
// ===== CLOUD ICON =====
void drawCloud(int x, int y) {
tft.fillCircle(x - 20, y, 15, LIGHT_BLUE);
tft.fillCircle(x, y - 8, 20, LIGHT_BLUE);
tft.fillCircle(x + 20, y, 15, LIGHT_BLUE);
tft.fillRoundRect(x - 35, y, 70, 20, 10, LIGHT_BLUE);
}
// ===== STATIC RAIN ICON =====
void drawRainIcon(int x, int y) {
drawCloud(x, y);
for (int i = 0; i < 5; i++) {
int dx = -24 + i * 12;
int dy = 28;
tft.drawLine(x + dx, y + dy, x + dx - 4, y + dy + 10, BLUE);
}
}
// ===== WEATHER ICON =====
void drawWeatherIcon(int code, int x, int y) {
if (code == 0) {
drawSun(x, y, 18);
}
else if (code <= 2) {
drawSun(x - 12, y - 7, 13);
drawCloud(x + 10, y + 10);
}
else if (code == 3) {
drawCloud(x, y);
}
else if ((code >= 51 && code <= 67) || (code >= 80 && code <= 82)) {
drawRainIcon(x, y);
}
else if (code >= 95) {
drawCloud(x, y);
tft.drawLine(x - 5, y + 28, x - 12, y + 43, YELLOW);
tft.drawLine(x + 10, y + 28, x + 3, y + 43, YELLOW);
} else {
drawCloud(x, y);
}
}
void drawWifiIcon(int cx, int cy, int level) {
const int radii[3] = { 14, 27, 40 };
for (int arc = 0; arc < 3; arc++) {
uint16_t color = (arc < level) ? CYAN : DARK_GRAY;
for (int deg = -150; deg <= -30; deg += 5) {
float angle = deg * PI / 180.0;
int x = cx + (int)(cos(angle) * radii[arc]);
int y = cy + (int)(sin(angle) * radii[arc]);
tft.fillCircle(x, y, 2, color);
}
}
// Base dot (the "device")
tft.fillCircle(cx, cy, 5, CYAN);
}
// ===== PAGE 1 - HOME =====
void drawHome() {
uint16_t bg = weather.isDay ? BLACK : DARK_BLUE;
tft.fillScreen(bg);
if (!weather.valid) {
drawCenteredText("NO DATA", 90, 3, RED);
drawCenteredText("CHECK CONNECTION", 135, 1, WHITE);
drawFooter();
return;
}
// Weather icon
drawWeatherIcon(weather.weatherCode, CENTER_X, 65);
// Temperature
drawCenteredText(String(weather.temperature, 1) + " C", 112, 3, WHITE);
// Location
drawCenteredText(LOCATION_NAME, 153, 2, CYAN);
// Weather condition
drawCenteredText(weatherDescription(weather.weatherCode), 178, 1, weatherColor(weather.weatherCode));
// Clock area
drawHomeClock();
drawFooter();
}
// ===== HOME CLOCK =====
void drawHomeClock() {
uint16_t bg = weather.isDay ? BLACK : DARK_BLUE;
// Only clear a small region.
// This prevents full-screen flicker.
tft.fillRect(82, 196, 76, 12, bg);
drawCenteredText(getTimeString(), 197, 1, GRAY);
}
// ===== PAGE 2 - TEMPERATURE =====
void drawTemperature() {
tft.fillScreen(BLACK);
drawHeader("TEMPERATURE", ORANGE);
int cx = 120;
int cy = 125;
int radius = 68;
int value = constrain((int)weather.temperature, 0, 40);
int filled = map(value, 0, 40, 0, 240);
// Temperature gauge
for (int i = 0; i < 240; i += 4) {
float angle = (-135.0 + i) * PI / 180.0;
int x = cx + cos(angle) * radius;
int y = cy + sin(angle) * radius;
uint16_t color = (i < filled) ? ORANGE : DARK_GRAY;
tft.fillCircle(x, y, 2, color);
}
// Main value
drawCenteredText(String(weather.temperature, 1), 101, 3, WHITE);
drawCenteredText("C", 138, 2, ORANGE);
drawCenteredText("FEELS " + String(weather.feelsLike, 1) + " C", 168, 1, CYAN);
drawFooter();
}
// ===== PAGE 3 - HUMIDITY =====
void drawHumidity() {
tft.fillScreen(BLACK);
drawHeader("HUMIDITY", BLUE);
int cx = 120;
int cy = 125;
int radius = 68;
int progress = constrain((int)weather.humidity, 0, 100);
int filled = map(progress, 0, 100, 0, 270);
for (int i = 0; i < 270; i += 3) {
float angle = (-135.0 + i) * PI / 180.0;
int x = cx + cos(angle) * radius;
int y = cy + sin(angle) * radius;
uint16_t color = (i < filled) ? BLUE : DARK_GRAY;
tft.fillCircle(x, y, 3, color);
}
drawCenteredText(String((int)weather.humidity) + "%", 105, 3, WHITE);
String comfort;
if (weather.humidity < 40) comfort = "DRY";
else if (weather.humidity < 70) comfort = "COMFORTABLE";
else if (weather.humidity < 85) comfort = "HUMID";
else
comfort = "VERY HUMID";
drawCenteredText(comfort, 153, 1, CYAN);
drawFooter();
}
// ===== PAGE 4 - WIND =====
void drawWind() {
tft.fillScreen(BLACK);
drawHeader("WIND", GREEN);
int cx = 120;
int cy = 104;
int radius = 49;
// Compass
tft.drawCircle(cx, cy, radius, DARK_GRAY);
drawCenteredText("N", 43, 1, WHITE);
drawCenteredText("S", 157, 1, WHITE);
tft.setCursor(62, 101);
tft.setTextSize(1);
tft.setTextColor(WHITE);
tft.print("W");
tft.setCursor(172, 101);
tft.print("E");
// Direction arrow
float angle = weather.windDirection * PI / 180.0;
int x2 = cx + sin(angle) * 38;
int y2 = cy - cos(angle) * 38;
tft.drawLine(cx, cy, x2, y2, GREEN);
tft.fillCircle(cx, cy, 5, GREEN);
// Wind speed
drawCenteredText(String(weather.windSpeed, 1) + " km/h", 174, 2, WHITE);
drawCenteredText(windDirectionText(weather.windDirection), 198, 1, CYAN);
drawFooter();
}
// ===== PAGE 5 - RAIN =====
void drawRain() {
tft.fillScreen(BLACK);
drawHeader("RAIN", LIGHT_BLUE);
int rain = weather.currentRainChance;
// Static weather icon
if (rain >= 60) {
drawRainIcon(CENTER_X, 68);
} else {
drawCloud(CENTER_X, 73);
}
// Rain percentage
drawCenteredText(String(rain) + "%", 105, 3, WHITE);
drawCenteredText("RAIN CHANCE", 140, 1, LIGHT_BLUE);
// Status
if (rain >= 60) {
drawCenteredText("HIGH", 158, 1, RED);
}
else if (rain >= 30) {
drawCenteredText("MODERATE", 158, 1, YELLOW);
} else {
drawCenteredText("LOW", 158, 1, GREEN);
}
// Animation area
if (rain >= 20) {
initializeRainAnimation();
}
drawFooter();
}
// ===== INITIALIZE RAIN ANIMATION =====
void initializeRainAnimation() {
for (int i = 0; i < RAIN_DROP_COUNT; i++) {
rainX[i] = RAIN_AREA_X + random(RAIN_AREA_W);
rainY[i] = RAIN_AREA_Y + random(RAIN_AREA_H);
}
rainInitialized = true;
}
// ===== UPDATE RAIN ANIMATION =====
void updateRainAnimation() {
if (currentPage != PAGE_RAIN) return;
if (weather.currentRainChance < 20) return;
if (millis() - lastRainAnimation < RAIN_ANIMATION_INTERVAL) {
return;
}
lastRainAnimation = millis();
uint16_t bg = BLACK;
// Erase old drops
for (int i = 0; i < RAIN_DROP_COUNT; i++) {
tft.drawLine(rainX[i], rainY[i], rainX[i] - 3, rainY[i] + 7, bg);
}
// Move drops
for (int i = 0; i < RAIN_DROP_COUNT; i++) {
rainY[i] += 5;
if (rainY[i] > RAIN_AREA_Y + RAIN_AREA_H) {
rainX[i] = RAIN_AREA_X + random(RAIN_AREA_W);
rainY[i] = RAIN_AREA_Y;
}
tft.drawLine(rainX[i], rainY[i], rainX[i] - 3, rainY[i] + 7, BLUE);
}
}
// ===== PAGE 6 - NEXT HOURS =====
void drawHourly() {
tft.fillScreen(BLACK);
drawHeader("NEXT HOURS", PURPLE);
for (int i = 0; i < 5; i++) {
int y = 52 + i * 31;
// Row separator
if (i > 0) {
tft.drawLine(25, y - 8, 215, y - 8, DARK_GRAY);
}
// Time
tft.setCursor(25, y);
tft.setTextSize(1);
tft.setTextColor(WHITE);
tft.print(weather.hourlyTime[i]);
// Weather
int code = weather.hourlyWeatherCode[i];
String condition;
if (code == 0) condition = "SUN";
else if (code <= 3) condition = "CLOUD";
else if (code >= 95) condition = "STORM";
else
condition = "RAIN";
tft.setCursor(75, y);
tft.setTextColor(weatherColor(code));
tft.print(condition);
// Temperature
tft.setCursor(142, y);
tft.setTextColor(WHITE);
tft.print(weather.hourlyTemp[i], 0);
tft.print("C");
// Rain
tft.setCursor(180, y);
tft.setTextColor(LIGHT_BLUE);
tft.print(weather.hourlyRainChance[i]);
tft.print("%");
}
drawFooter();
}
// ===== PAGE 7 - FORECAST =====
// UI FIX:
// The card border (drawRoundRect) previously spanned x=15..225
// (width 210). For the TOP row, the corners of that rectangle
// fell outside the visible round area of the screen and were
// clipped. The card width below was reduced to 190px
// (x=25..215) which keeps every corner, on every row, safely
// inside the round bezel. Text start x was nudged in slightly
// to match the new card padding.
void drawForecast() {
tft.fillScreen(BLACK);
drawHeader("3-DAY FORECAST", CYAN);
const char* labels[] = {
"TODAY",
"TOMORROW",
"DAY 3"
};
// Card geometry (UI fix: narrower so it never touches
// the round bezel, even on the top row).
const int CARD_X = 25;
const int CARD_W = 190;
for (int i = 0; i < 3; i++) {
int y = 62 + i * 48;
// Card
tft.drawRoundRect(CARD_X, y - 5, CARD_W, 40, 8, DARK_GRAY);
// Day
tft.setCursor(CARD_X + 8, y + 4);
tft.setTextSize(1);
tft.setTextColor(WHITE);
tft.print(labels[i]);
// Temperature
tft.setCursor(CARD_X + 65, y + 4);
tft.print(weather.dailyTempMin[i], 0);
tft.print("/");
tft.print(weather.dailyTempMax[i], 0);
tft.print("C");
// Rain
tft.setCursor(CARD_X + 120, y + 4);
tft.setTextColor(LIGHT_BLUE);
tft.print(weather.dailyRainChance[i]);
tft.print("%");
// Weather
tft.setCursor(CARD_X + 155, y + 4);
tft.setTextColor(weatherColor(weather.dailyWeatherCode[i]));
int code = weather.dailyWeatherCode[i];
if (code == 0) tft.print("SUN");
else if (code <= 3) tft.print("CLD");
else if (code >= 95) tft.print("STM");
else
tft.print("RAIN");
}
drawFooter();
}
// ===== PAGE 8 - SYSTEM =====
void drawSystem() {
tft.fillScreen(BLACK);
drawHeader("SYSTEM", CYAN);
// WIFI
tft.setCursor(25, 57);
tft.setTextSize(1);
tft.setTextColor(WHITE);
tft.print("WIFI");
tft.setCursor(125, 57);
if (WiFi.status() == WL_CONNECTED) {
tft.setTextColor(GREEN);
tft.print("ONLINE");
} else {
tft.setTextColor(RED);
tft.print("OFFLINE");
}
// RSSI
tft.setCursor(25, 82);
tft.setTextColor(WHITE);
tft.print("RSSI");
tft.setCursor(125, 82);
if (WiFi.status() == WL_CONNECTED) {
tft.setTextColor(CYAN);
tft.print(WiFi.RSSI());
tft.print(" dBm");
} else {
tft.print("--");
}
// API
tft.setCursor(25, 107);
tft.setTextColor(WHITE);
tft.print("API");
tft.setCursor(125, 107);
if (apiOnline) {
tft.setTextColor(GREEN);
tft.print("ONLINE");
} else {
tft.setTextColor(RED);
tft.print("OFFLINE");
}
// LOCATION
tft.setCursor(25, 132);
tft.setTextColor(WHITE);
tft.print("LOCATION");
tft.setCursor(125, 132);
tft.setTextColor(CYAN);
tft.print(LOCATION_NAME);
// TEMP
tft.setCursor(25, 157);
tft.setTextColor(WHITE);
tft.print("TEMP");
tft.setCursor(125, 157);
tft.print(weather.temperature, 1);
tft.print(" C");
// STATUS
tft.setCursor(25, 182);
tft.setTextColor(WHITE);
tft.print("STATUS");
tft.setCursor(125, 182);
if (weather.valid) {
tft.setTextColor(GREEN);
tft.print("READY");
} else {
tft.setTextColor(RED);
tft.print("NO DATA");
}
drawFooter();
}
// ===== RENDER PAGE =====
void renderPage() {
// Rain animation must be initialized
// only when entering the page.
rainInitialized = false;
switch (currentPage) {
case PAGE_HOME:
drawHome();
break;
case PAGE_TEMP:
drawTemperature();
break;
case PAGE_HUMIDITY:
drawHumidity();
break;
case PAGE_WIND:
drawWind();
break;
case PAGE_RAIN:
drawRain();
break;
case PAGE_HOURLY:
drawHourly();
break;
case PAGE_FORECAST:
drawForecast();
break;
case PAGE_SYSTEM:
drawSystem();
break;
}
}
// ===== WEATHER API URL =====
String getWeatherURL() {
String url = "https://api.open-meteo.com/v1/forecast";
url += "?latitude=" + String(LATITUDE, 4);
url += "&longitude=" + String(LONGITUDE, 4);
url +=
"¤t="
"temperature_2m,"
"relative_humidity_2m,"
"apparent_temperature,"
"weather_code,"
"wind_speed_10m,"
"wind_direction_10m,"
"pressure_msl,"
"is_day";
url +=
"&hourly="
"temperature_2m,"
"precipitation_probability,"
"weather_code";
url +=
"&daily="
"temperature_2m_max,"
"temperature_2m_min,"
"precipitation_probability_max,"
"weather_code,"
"sunrise,"
"sunset,"
"uv_index_max";
url += "&timezone=" TIMEZONE;
url += "&forecast_days=3";
url += "&temperature_unit=celsius";
url += "&wind_speed_unit=kmh";
return url;
}
// ===== PARSE WEATHER =====
bool parseWeather(String payload) {
JsonDocument doc;
DeserializationError error = deserializeJson(doc, payload);
if (error) {
Serial.print("JSON ERROR: ");
Serial.println(error.c_str());
return false;
}
// CURRENT
JsonObject current = doc["current"];
if (current.isNull()) {
Serial.println("CURRENT DATA MISSING");
return false;
}
weather.temperature = current["temperature_2m"] | 0.0;
weather.humidity = current["relative_humidity_2m"] | 0.0;
weather.feelsLike = current["apparent_temperature"] | 0.0;
weather.weatherCode = current["weather_code"] | 0;
weather.windSpeed = current["wind_speed_10m"] | 0.0;
weather.windDirection = current["wind_direction_10m"] | 0.0;
weather.pressure = current["pressure_msl"] | 0.0;
int isDay = current["is_day"] | 1;
weather.isDay = (isDay == 1);
// HOURLY
JsonArray hourlyTime = doc["hourly"]["time"];
JsonArray hourlyTemp = doc["hourly"]["temperature_2m"];
JsonArray hourlyRain = doc["hourly"]["precipitation_probability"];
JsonArray hourlyCode = doc["hourly"]["weather_code"];
struct tm timeinfo;
int currentHour = 0;
if (getLocalTime(&timeinfo, 1000)) {
currentHour = timeinfo.tm_hour;
}
for (int i = 0; i < 12; i++) {
int index = currentHour + i;
// Safety check
if (index >= hourlyTemp.size()) {
weather.hourlyTemp[i] = weather.temperature;
weather.hourlyRainChance[i] = 0;
weather.hourlyWeatherCode[i] = weather.weatherCode;
weather.hourlyTime[i] = "--:--";
continue;
}
weather.hourlyTemp[i] = hourlyTemp[index] | weather.temperature;
weather.hourlyRainChance[i] = hourlyRain[index] | 0;
weather.hourlyWeatherCode[i] = hourlyCode[index] | weather.weatherCode;
// Extract HH:MM
// Example:
// 2026-09-11T14:00
//
// Result:
// 14:00
String fullTime = hourlyTime[index] | "";
if (fullTime.length() >= 16) {
weather.hourlyTime[i] = fullTime.substring(11, 16);
} else {
weather.hourlyTime[i] = "--:--";
}
}
weather.currentRainChance = weather.hourlyRainChance[0];
// DAILY
JsonArray dailyMax = doc["daily"]["temperature_2m_max"];
JsonArray dailyMin = doc["daily"]["temperature_2m_min"];
JsonArray dailyRain = doc["daily"]["precipitation_probability_max"];
JsonArray dailyCode = doc["daily"]["weather_code"];
JsonArray dailyDate = doc["daily"]["time"];
JsonArray dailySunrise = doc["daily"]["sunrise"];
JsonArray dailySunset = doc["daily"]["sunset"];
JsonArray dailyUV = doc["daily"]["uv_index_max"];
for (int i = 0; i < 3; i++) {
weather.dailyTempMax[i] = dailyMax[i] | 0.0;
weather.dailyTempMin[i] = dailyMin[i] | 0.0;
weather.dailyRainChance[i] = dailyRain[i] | 0;
weather.dailyWeatherCode[i] = dailyCode[i] | 0;
weather.dailyDate[i] = dailyDate[i] | "";
weather.dailyUV[i] = dailyUV[i] | 0.0;
}
if (dailySunrise.size() > 0) {
weather.sunrise = dailySunrise[0] | "";
}
if (dailySunset.size() > 0) {
weather.sunset = dailySunset[0] | "";
}
if (dailyUV.size() > 0) {
weather.uvIndex = dailyUV[0] | 0.0;
}
weather.valid = true;
return true;
}
// ===== FETCH WEATHER =====
bool fetchWeather() {
if (WiFi.status() != WL_CONNECTED) {
Serial.println("WIFI NOT CONNECTED");
apiOnline = false;
screenDirty = true;
return false;
}
Serial.println();
Serial.println("================================");
Serial.println("FETCHING WEATHER");
Serial.println("================================");
isFetching = true;
// Loading screen is shown only once.
drawLoadingScreen("FETCHING WEATHER...");
WiFiClientSecure client;
// Prototype / testing mode.
client.setInsecure();
HTTPClient http;
String url = getWeatherURL();
Serial.println(url);
if (!http.begin(client, url)) {
Serial.println("HTTP BEGIN FAILED");
isFetching = false;
apiOnline = false;
screenDirty = true;
return false;
}
http.setTimeout(15000);
int httpCode = http.GET();
Serial.print("HTTP CODE: ");
Serial.println(httpCode);
if (httpCode <= 0) {
Serial.print("HTTP ERROR: ");
Serial.println(http.errorToString(httpCode));
http.end();
isFetching = false;
apiOnline = false;
screenDirty = true;
return false;
}
if (httpCode != HTTP_CODE_OK) {
Serial.println("API ERROR");
http.end();
isFetching = false;
apiOnline = false;
screenDirty = true;
return false;
}
String payload = http.getString();
Serial.print("PAYLOAD SIZE: ");
Serial.println(payload.length());
bool result = parseWeather(payload);
http.end();
isFetching = false;
if (result) {
apiOnline = true;
lastApiUpdate = millis();
Serial.println("WEATHER UPDATED");
Serial.print("Temperature: ");
Serial.println(weather.temperature);
Serial.print("Humidity: ");
Serial.println(weather.humidity);
Serial.print("Weather: ");
Serial.println(weatherDescription(weather.weatherCode));
Serial.print("Wind: ");
Serial.println(weather.windSpeed);
Serial.print("Rain Chance: ");
Serial.println(weather.currentRainChance);
screenDirty = true;
return true;
}
apiOnline = false;
screenDirty = true;
return false;
}
// ===== LOADING SCREEN =====
void drawLoadingScreen(String message) {
tft.fillScreen(BLACK);
drawCenteredText("SMART WEATHER", 48, 2, CYAN);
drawCenteredText("STATION", 73, 2, WHITE);
// Loading ring
for (int i = 0; i < 12; i++) {
float angle = i * 2.0 * PI / 12.0;
int x = CENTER_X + cos(angle) * 42;
int y = CENTER_Y + sin(angle) * 42;
uint16_t color = (i == 0) ? CYAN : DARK_GRAY;
tft.fillCircle(x, y, 4, color);
}
drawCenteredText(message, 182, 1, WHITE);
}
// ===== WIFI CONNECT =====
bool connectWiFi() {
Serial.println();
Serial.println("CONNECTING TO WIFI...");
tft.fillScreen(BLACK);
drawCenteredText("CONNECTING", 26, 2, CYAN);
drawWifiIcon(CENTER_X, 95, 0);
drawCenteredText("WI-FI", 145, 2, WHITE);
drawCenteredText(WIFI_SSID, 178, 1, GRAY);
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
unsigned long start = millis();
int iconFrame = 0;
while (WiFi.status() != WL_CONNECTED && millis() - start < 15000) {
drawWifiIcon(CENTER_X, 95, iconFrame % 4);
iconFrame++;
delay(250);
Serial.print(".");
}
Serial.println();
if (WiFi.status() == WL_CONNECTED) {
wifiOnline = true;
wifiConnecting = false;
drawWifiIcon(CENTER_X, 95, 3);
Serial.println("WIFI CONNECTED");
Serial.print("IP: ");
Serial.println(WiFi.localIP());
Serial.print("RSSI: ");
Serial.print(WiFi.RSSI());
Serial.println(" dBm");
return true;
}
wifiOnline = false;
Serial.println("WIFI CONNECTION FAILED");
return false;
}
// ===== START WIFI RECONNECT =====
void startWiFiReconnect() {
Serial.println("START WIFI RECONNECT");
WiFi.mode(WIFI_STA);
WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
wifiConnecting = true;
wifiConnectStart = millis();
}
// ===== HANDLE WIFI =====
void handleWiFi() {
wl_status_t status = WiFi.status();
// Connected
if (status == WL_CONNECTED) {
if (!wifiOnline) {
Serial.println("WIFI CONNECTED");
screenDirty = true;
}
wifiOnline = true;
wifiConnecting = false;
return;
}
wifiOnline = false;
// Currently connecting
if (wifiConnecting) {
if (millis() - wifiConnectStart > WIFI_CONNECT_TIMEOUT) {
Serial.println("WIFI CONNECT TIMEOUT");
WiFi.disconnect(true);
wifiConnecting = false;
lastWifiRetry = millis();
}
return;
}
// Start another attempt
if (millis() - lastWifiRetry >= WIFI_RETRY_INTERVAL) {
lastWifiRetry = millis();
startWiFiReconnect();
}
}
// ===== NTP TIME =====
void setupTime() {
// The offset comes from USER CONFIGURATION.
configTime(
GMT_OFFSET_SEC,
DST_OFFSET_SEC,
"pool.ntp.org",
"time.nist.gov",
"time.google.com"
);
Serial.println("SYNCING TIME...");
struct tm timeinfo;
if (getLocalTime(&timeinfo, 10000)) {
Serial.println("TIME SYNCED");
Serial.println(&timeinfo, "%Y-%m-%d %H:%M:%S");
} else {
Serial.println("TIME SYNC FAILED");
}
}
// ===== BUTTON HANDLER =====
void handleButton() {
button.loop(); // MUST call the loop() function first
// The moment the button goes down, remember when it happened.
if (button.isPressed())
buttonPressStart = millis();
// The action is chosen when the button comes back up.
if (button.isReleased()) {
unsigned long duration = millis() - buttonPressStart;
if (duration >= VERY_LONG_PRESS_TIME) {
// VERY LONG PRESS -> back to the home page
currentPage = PAGE_HOME;
screenDirty = true;
Serial.println("VERY LONG PRESS -> HOME");
} else if (duration >= LONG_PRESS_TIME) {
// LONG PRESS -> ask the weather API for fresh data
pendingRefresh = true;
Serial.println("LONG PRESS -> REFRESH");
} else {
// SHORT PRESS -> next page
currentPage = (Page)((currentPage + 1) % PAGE_COUNT);
screenDirty = true;
Serial.print("SHORT PRESS -> PAGE ");
Serial.println(currentPage + 1);
}
}
}
// ===== PROCESS MANUAL REFRESH =====
void handleManualRefresh() {
if (!pendingRefresh) return;
pendingRefresh = false;
fetchWeather();
}
// ===== AUTO API UPDATE =====
void handleApiUpdate() {
if (!weather.valid) {
return;
}
if (millis() - lastApiUpdate >= API_UPDATE_INTERVAL) {
fetchWeather();
}
}
// ===== CLOCK =====
String getTimeString() {
struct tm timeinfo;
if (!getLocalTime(&timeinfo, 10)) {
return "--:--";
}
char buffer[10];
strftime(buffer, sizeof(buffer), "%H:%M", &timeinfo);
return String(buffer);
}
// ===== HANDLE CLOCK =====
void handleClock() {
if (currentPage != PAGE_HOME) {
return;
}
if (millis() - lastClockUpdate < CLOCK_UPDATE_INTERVAL) {
return;
}
lastClockUpdate = millis();
if (weather.valid && !isFetching) {
drawHomeClock();
}
}
// ===== SETUP =====
void setup() {
Serial.begin(115200);
delay(500);
Serial.println();
Serial.println("================================");
Serial.println("SMART WEATHER STATION");
Serial.println(LOCATION_NAME);
Serial.println("================================");
// BUTTON
// ezButton already set the pin to INPUT_PULLUP in its constructor.
button.setDebounceTime(BUTTON_DEBOUNCE);
// TFT
tft.begin();
tft.setRotation(2);
tft.fillScreen(BLACK);
// BOOT SCREEN
drawCenteredText("SMART WEATHER", 65, 2, CYAN);
drawCenteredText("STATION", 92, 2, WHITE);
drawCenteredText(LOCATION_NAME, 135, 2, YELLOW);
delay(1500);
// WIFI
if (connectWiFi()) {
setupTime();
delay(500);
fetchWeather();
} else {
tft.fillScreen(BLACK);
drawCenteredText("WIFI ERROR", 82, 2, RED);
drawCenteredText("CHECK SETTINGS", 120, 1, WHITE);
drawCenteredText("RETRYING...", 150, 1, GRAY);
delay(1500);
}
screenDirty = true;
}
// ===== LOOP =====
void loop() {
// Input
handleButton();
// WiFi
handleWiFi();
// Manual refresh
handleManualRefresh();
// Automatic API update
handleApiUpdate();
// Clock
handleClock();
// Static page rendering
if (screenDirty && !isFetching) {
renderPage();
screenDirty = false;
}
// Rain animation
updateRainAnimation();
}
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Connect the round TFT LCD display and the push button to the ESP32 as the provided wiring diagram.
- Connect the ESP32 board to your PC via a USB cable
- Open Arduino IDE on your PC.
- Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
- Navigate to the Libraries icon on the left bar of the Arduino IDE.
- Search “DIYables TFT Round”, then find the DIYables_TFT_Round library by DIYables.
- Click Install button to install the library.
- A windows appears to ask you to install dependencies.
- Click Install All button to install all library dependencies.
- Type “ArduinoJson” in the search box, find the ArduinoJson library by Benoit Blanchon, then click Install.
- Type “ezButton” in the search box, find the ezButton library by ArduinoGetStarted, then click Install.
- Copy the above code and paste it into the Arduino IDE editor.
- Replace WIFI_SSID and WIFI_PASSWORD with your own WiFi name and password.
- Replace LATITUDE, LONGITUDE, LOCATION_NAME, TIMEZONE and GMT_OFFSET_SEC with the values of your own city.
- Click the Upload button in Arduino IDE to upload the code to the ESP32.
- Open the Serial Monitor and set the baud rate to 115200.
- Watch the boot screen, then the WiFi screen, then the first weather page.
- Press the button to step to the next page.
- Check the result on the Serial Monitor.
8
Serial.println("Hello World!");
Message (Enter to send message to 'ESP32 Dev Module' on 'COM15')
New Line
9600 baud
================================
SMART WEATHER STATION
SEOUL
================================
CONNECTING TO WIFI...
......
WIFI CONNECTED
IP: 192.168.1.113
RSSI: -52 dBm
SYNCING TIME...
TIME SYNCED
2026-09-22 09:15:42
================================
FETCHING WEATHER
================================
https://api.open-meteo.com/v1/forecast?latitude=37.5665&longitude=126.9780¤t=...
HTTP CODE: 200
PAYLOAD SIZE: 5188
WEATHER UPDATED
Temperature: 21.80
Humidity: 68.00
Weather: OVERCAST
Wind: 13.70
Rain Chance: 39
SHORT PRESS -> PAGE 2
SHORT PRESS -> PAGE 3
LONG PRESS -> REFRESH
VERY LONG PRESS -> HOME
Setting Your Own City
Seoul is the place shipped with the sketch. Five lines near the top control it:
#define LATITUDE 37.5665
#define LONGITUDE 126.9780
#define LOCATION_NAME "SEOUL"
#define TIMEZONE "Asia%2FSeoul"
#define GMT_OFFSET_SEC (9 * 3600)
- LATITUDE and LONGITUDE point at your city. Any map website will give them.
- LOCATION_NAME is the label drawn on the screen. A short name fits the round display better.
- TIMEZONE goes into a web address, so the / character has to be written as %2F. Europe/Berlin becomes Europe%2FBerlin.
- GMT_OFFSET_SEC feeds the NTP clock. Berlin in winter is UTC+1, which is (1 * 3600).
- DST_OFFSET_SEC adds summer time where it applies. Use 3600 in that case, otherwise leave it at 0.
※ NOTE THAT:
Readings arrive in Celsius and km/h. Change the temperature_unit and wind_speed_unit parameters inside getWeatherURL() to fahrenheit and mph if you prefer imperial units.
Code Explanation
Check the explanations given in the source code comments for each line!
Troubleshooting
- Nothing appears on the display. Recheck SCL on GPIO18 and SDA on GPIO23. Those two belong to the hardware SPI bus and cannot be moved.
- The sketch is stuck on the WiFi screen. The ESP32 only joins 2.4 GHz networks. A 5 GHz-only network will never connect.
- HTTP CODE is negative. The secure connection failed. Confirm the ESP32 has Internet access, and note that a captive-portal WiFi will block the API call.
- The clock shows --:--. The NTP sync did not finish. Some networks block UDP port 123, which NTP needs.
- The sketch does not fit in flash. In the Arduino IDE, open Tools and pick a partition scheme with a bigger application area, such as Huge APP.
Video Tutorial
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