Arduino: real timekeeping and alarms with the DS3231 RTC
Give your Arduino a real clock with the DS3231 RTC module. Set the time, read it back, and fire alarms that survive power loss, drift, and reboot.
Tag
#time
4 tutorials
Arduino: location and time from a NEO-6M GPS module
Read latitude, longitude, and the exact UTC time from a $12 NEO-6M GPS module over serial. Wiring, the TinyGPS++ library, and why the fix takes 5 minutes outside.
ESP32: location and time from a NEO-M8N GPS module
Wire a NEO-M8N GPS module to an ESP32 over serial, parse NMEA for position and UTC time, and understand why your first fix takes minutes.
ESP32: sync time over NTP and handle timezones + DST correctly
Get real wall-clock time on the ESP32 over NTP: settimeofday, the TZ string that handles DST for you, and a self-hosted angle pointing at your own router or a Pi.