Micro to tell when its night time?

[cupoftea]

We want to light up our house name by LEDs. Obviously only at night. So we need to sense when its day and night. Now, all light sensors available are horrifically bad in terms of tolerance. -And we don’t want to calibrate every light sensor. So the only way (would you agree?) is to use a light change algorithm. That is, read the light level every 10 minutes. What you find, is a massive change in light level from dawn/dusk/dawn. Then, with some extra coding…..you can pretty well say when its day and when its night.

Would you agree that this is the best way to distinguish day and night?

 

[danadakk]

You can always get time off internet with a ESP8266 or ESP32 and use that to
control leds.

Getting Time From Internet Using ESP8266 | NTP Clock Project With ESP8266 Nodemcu

Getting Time From Internet Using ESP8266 | NTP Clock Project With ESP8266 Nodemcu: In this tutorial we’ll see how to get time using the ESP8266/nodemcu with Arduino IDE. Getting time is especially useful in data logging to timestamp your readings. If your ESP8266 project has access to the...

www.instructables.com

Getting Date and Time with ESP32 (NTP Client) | Random Nerd Tutorials

This tutorials shows how to get date and time using an NTP Client with the ESP32 and Arduino IDE. Getting date and time is especially useful in data logging.

randomnerdtutorials.com

Regards, Dana.

 

[Aussie Susan]

There are well known formulae for calculating sunrise and subset times for a given location and date - a quick Google search shows pages such as https://en.wikipedia.org/wiki/Sunrise_equation
Susan

 

[betwixt]

I do it by keeping a 'time server' running at home. An ESP32 and DS3231 to give a back-up clock run continuously and send an MQTT packet every second. The data is JSON formatted and gives hours, minutes, seconds, date, month, year, day of the week, GMT/DST and finally a 1 or 0 to indicate daytime or night. It checks for connection to NTP at start up and every few hours and syncs if necessary. The DST and daytime calculation is dynamic so it updates every day. The day/night triggers at sunrise and sunset so it needs to be programmed for your latitude and longitude.
It controls all kinds of equipment, including wall clock displays, time overlay into CCTV pictures and of course the lighting. Sounds like what you need.

Brian.