TechOnIt Hardware Test — 🕜 DS3231

A simple hardware test project for the DS3231 Real-Time Clock (RTC) module using an ESP32.

The project:

• Connects the ESP32 to Wi-Fi.
• Retrieves the current time from an NTP server.
• Synchronizes the DS3231 clock.
• Reads the time from the DS3231 every second.
• Prints the current date and time to Serial Monitor.

Hardware

• ESP32 / NodeMCU ESP32
• DS3231 RTC module
• CR2032 3V coin cell battery

Wiring

DS3231	ESP32
VCC	3.3V
GND	GND
SDA	GPIO 4
SCL	GPIO 5

Battery: The DS3231 module uses a standard CR2032 3V non-rechargeable battery as a backup power source to keep time when the main power is disconnected.

Dependencies

• Arduino Framework
• RTClib
• ESP32 Wi-Fi library
• ESP32 Wire (I2C)

Configuration

Update the Wi-Fi credentials in the source code:

const char* WIFI_SSID = "YOUR_WIFI";
const char* WIFI_PASSWORD = "YOUR_PASSWORD";

The current implementation uses:

Wire.begin(4, 5);

So:

SDA → GPIO 4
SCL → GPIO 5

How It Works

ESP32
  │
  ├── Connect to Wi-Fi
  │
  ├── Get current time from NTP
  │
  ├── Set DS3231 time
  │
  └── Read DS3231 every second
          │
          └── Serial Monitor

Serial Output

Example:

Connecting...
WiFi connected
RTC updated!

2026-10-01 21:37:01
2026-10-01 21:37:02
2026-10-01 21:37:03

Purpose

This repository is part of the TechOnIt Hardware Test collection and is intended for validating individual hardware modules before integrating them into the TechOnIt Edge Node system.

Related Projects

• agent-node — TechOnIt Edge Node firmware
• agent-controller — Raspberry Pi Controller
• agent-sdk — Shared SDK and communication contracts

License

Part of the TechOnIt open-source ecosystem.