Weather Monitor Module

What is it?

This repo shows my attempt to build a wireless weather monitor module which connects to the internet via WiFi and pulling some useful weather status information every let's say 5 minutes.

How does it work?

The brain of the module is ESP32 microcontroller, a low-powered with built-in WiFi and Bluetooth functionality, which submits an HTTP request to OpenWeatherMap as the weather data server. The server returns a response to the ESP32 which contains all the required information. Finally, it reads the data into JSON format, represents them in a TFT display, and reacting to them using, changing the text color, different LED indicators, or generating a gentle beep sound.

Features

Wireless connection to WiFi
Various weather info are available: temperature, feels-like temperature, min/max temperature, pressure, humidity, wind speed, visibility
Temperature status LEDs: red (hot), green (normal), blue (cold)
Weather temperature LED (yellow) and buzzer: in case of extreme weather (e.g. rain or snow)
Change texts color when a status is not normal (e.g. high wind speed, low visibility, rain)
Report date and time of the latest update using NTP client

Prerequisites

Access:
- Connection to a WiFi network
- OpenWeatherMap enabled API to request weather data (account creation is required, see here)
Hardware:
- EPS32 microcontroller
- 1.8 SPI TFT 128x160 display
- Four LEDs (red, green, blue, and yellow)
- A Piezo buzzer
- Few 100 Ohm resistors for LEDs
- A breadboard and some wires (or soldering prototype board)
Software
- Arduino IDE with ESP32 Add-on
- Arduino json library
- Adafruit TFT display driver library

Wiring

The wiring is pretty straightforward as follows (see ESP32 Pinout Reference):

TFT display pins:
- CS ➡ 12
- RST ➡ 14
- DC ➡ 13
- SCLK ➡ 22
- MOSI ➡ 21
LEDs pin:
- Blue ➡ 25
- Green ➡ 26
- Red ➡ 27
- Yellow ➡ 32
Buzzer pin ➡ 15

Code adjustment

A few parameters have to be known and set before compiling the sketch.

SSID : WiFi network's name
PASSWORD : WiFi password
APIKEY : Open weather map api key (see the references)
CITY : e.g. "Antwerp"
COUNTRY : e.g. "BE"
TIMEZONE : Time zone respect to GMT e.g. 7200 for GMT+2h

const char* ssid = "SSID";
const char* password = "PASSWORD";

// Your Domain name with URL path or IP address with path (see references)
String openWeatherMapApiKey = "APIKEY";

// Replace with your country code and city
String city = "CITY";                // e.g. "Antwerp"
String countryCode = "COUNTRY";      // e.g. "BE"
unsigned long timezone = "TIMEZONE"  // e.g. 7200 (GMT+2)

Blow parameters work just fine with their default values but they can be also adjusted based on your needs.

// LED indicators
#define LED_COLD        25    // pin
#define LED_NORM        26    // pin
#define LED_HOT         27    // pin
#define LED_WEATHER     32    // pin

// Set thresholds
#define TEMP_COLD       5.0   // Celsius
#define TEMP_HOT        25.0  // Celsius
#define WIND_SPEED_HIGH 30.0  // km/h 
#define VISIBILITY_LOW  2.0   // km
#define HUMIDITY_HIGH   90.0  // Percent

// Define settings for buzzer
#define BUZZER_PIN      15    // pin
#define BUZZER_FRQ      2000  // Hz
#define BUZZER_CHANNEL  0     // PWM channel

// Define pins of TFT screen
#define TFT_CS          12    // pin
#define TFT_RST         14    // pin 
#define TFT_DC          13    // pin
#define TFT_SCLK        22    // pin
#define TFT_MOSI        21    // pin    

// Pulling time in Milliseconds (e.g. 5 min)
unsigned long timerDelay = 300000;

References

Some useful links that part of this work is based on them are as follows:

hghcomphys/weather-monitor-module