Arduino Data Logger (Log Temperature, Humidity, Time on SD Card and Computer)

The Arduino Data Logger system integrates multiple sensing, timing, and storage modules to capture environmental data over time. At the center of the system is an Arduino Mega 2560 (or compatible Arduino board) connected via a breadboard and wires to a DHT11 sensor, a DS3231 Real-Time Clock (RTC) module, and an SD card module. The DHT11 temperature and humidity sensor measures ambient atmospheric conditions, transmitting digital signal data to the microcontroller. Simultaneously, the DS3231 RTC module keeps precise track of the current date and time using a crystal oscillator and communicates this timing information to the Arduino via the I2C communication protocol. Once the Arduino gathers the environmental readings from the DHT11 and the accurate timestamp from the DS3231, it handles the data in two distinct ways. First, it writes the formatted data text string directly to a physical SD card inserted into the SPI-based SD card module, ensuring non-volatile offline storage. Second, the Arduino streams the exact same dataset over a serial USB connection to a connected computer or laptop running PLX-DAQ software, which automatically logs the incoming values into an active Microsoft Excel spreadsheet in real time.