ESP32-WeatherStationRTC

This project is an ESP32-based desk clock with functionality of monitoring the temperature, atmospheric pressure and humidity in the air. It is coded using the arduino framework.

Features

• Time and date: Utilizes the DS3231 RTC module for accurate timekeeping and displays the current time and date.
• Temperature, Humidity, and Pressure Measurement: Uses the BME280 sensor to measure and display the current temperature, humidity, and pressure.
• Automatic Brightness Adjustment: Adjusts the LED matrix display brightness based on the ambient light level detected by the BH1750 sensor.
• WiFi Time Sync: In case the RTC loses power, the device attempts to sync the time via an NTP server over WiFi (needs an open AP).
• Button Control: A button allows cycling through the display modes and turning the display on/off with a long press.

Hardware Requirements

• ESP32 (other arduino compatible boards are okay, just change the pins)
• MAX7219 LED matrix module (8 devices needed)
• DS3231 Real-Time Clock module
• BME280 sensor module (temperature, humidity, pressure)
• BH1750 light sensor module
• (OPTIONAL) PushButton (the default button is the BOOT button in the ESP32-DevKitC V4 devboard)

Software Requirements

• PlatformIO
• If you use the Arduino IDE you will need this libraries:
  • majicdesigns/MD_MAX72XX@^3.5.1
  • majicdesigns/MD_Parola@^3.7.3
  • adafruit/RTClib@^2.1.1
  • arduino-libraries/NTPClient@^3.2.1
  • jchristensen/Timezone@^1.2.4
  • adafruit/Adafruit BME280 Library@^2.2.4
  • adafruit/Adafruit Unified Sensor@^1.1.14
  • claws/BH1750@^1.3.0
  • thomasfredericks/Bounce2@^2.71

Setup

Hardware Setup:

• The reference board is an ESP32-DevKitC V4

PushButton	ESP32-DevKitC V4
+	0
-	GND

N.B. The PIN 0 is the one used by the BOOT button on the ESP32-DevKitC V4 devboard so it's not necessary using an external push button.

I2C DEVICES	ESP32-DevKitC V4
VCC	3V3
GND	GND
SCL	22
SDA	21

MAX7219 (SPI Interface)	ESP32-DevKitC V4
VCC	5V
GND	GND
CLK	18
DIN	23
CS	5

N.B. The two 4 devices displays needs to be connected like this:

Software Setup:

• Install the PlatformIO IDE (or the VSCode extension).
• Connect the board to your computer.
• Update the pin definitions and the NTP servers if needed.
• Change the I2C addresses if needed.
• Change the timezone if needed.
• Compile and upload the code to your ESP32 board.

First boot

At the first boot the display shows "POWER LOST" and if you push the button it tries to connect to the first open AP it finds to sync the RTC with an NTP server. So:

• Set up an open AP (mobile hotspot is ok)
• Press the push button on the clock
• Wait for it to connect to the server

IMPORTANT: this procedure is necessary whenever the DS3231 loses power (i.e. when the battery runs out or one is not inserted and the ESP32 loses power) and this is the only way the clock is synced.

Usage

• The device will automatically display the time and temperature upon startup.
• Press the button to cycle through the different display modes:
  • time & temperature (in Celsius)
  • date (DDD DD MMM YYYY)
  • humidity & pressure (in hPa)
• Hold the button for more than 500ms to turn off the display. Press again to turn it back on.

License

This project is licensed under the GNU GENERAL PUBLIC LICENSE - see the LICENSE file for details.

Credits

Leonardo Mirabella