Embedded Lab

Analog wall clocks are an old invention. Besides telling time they also serve as a wall decoration. Most of the modern days inexpensive wall clocks are not good at keeping the time accurately. Also, they usually don’t have auto-adjustment for daylight saving time. Victor-chew shares his attempt to tether a cheap IKEA analog wall clock to the ESP8266 WiFi microcontroller and make it sync with a NTP server for accurate timekeeping as well as auto adjustment to daylight savings.

In this project, I connected a cheap $2 Ikea analog clock to the ESP-12/NodeMCU dev module and synchronized the clock time with NTP time (localized with Google Maps Timezone API). On startup, simply connect to the device configuration AP and configure your Wi-Fi login credentials and physical clock time. The config web page will capture your current location automatically using HTML5 Geolocation and use that to automatically figure the local time and DST offset via the Google Maps Timezone API.

The clock will sync within a few seconds of NTP time, take care of DST automatically and only cost a few dollars more due to the low cost of ESP12/ESP8266. The only problem that remains is the practical need to run this clock from the mains. Even when connected to a 10,000mha battery pack, it will only last for about 6 to 7 days.

For seven-segment LED based NTP clock, click here.