EpochLog DS3231 Time-Series Logger

About this project

EpochLog DS3231 Time-Series Logger is a standalone sensor data recorder that permanently saves timestamped readings to a MicroSD card — even when power is removed. A DS3231 real-time clock module maintains the current date and time to within ±2 minutes per year, powered by a CR2032 coin cell between Arduino sessions. Every 10 seconds, the system reads an LDR light sensor, pairs the reading with a precise timestamp from the DS3231, and appends one row to a CSV file on the SD card. The LCD shows the live clock and running log entry count. Pull the SD card, plug it into a computer, and open the CSV in Microsoft Excel or Google Sheets — every reading across the entire session appears as a timestamped data table ready for analysis, graph generation, or export. This is how real IoT weather stations, environmental monitors, industrial data loggers, and scientific instruments work. The system demonstrates simultaneous I2C (DS3231 + LCD) and SPI (SD card) bus operation — a multi-protocol architecture used in virtually every embedded product that stores data. Build time: 3 hours.

What you get

• Complete, commented source code
• Full components list with quantities
• Pin-by-pin wiring guide and connection table
• Step-by-step upload and testing guide
• Project report (.docx, IEEE style)
• Presentation slides (.pptx)