How to implement relay switching once a day?

Question

Microcontrollers

The bottom line is, alternately working pumps should switch once a day (one turned off the other turned on), but the catch is that the board will not have access to either a PC or the Internet to find out the time, I'm in a stupor

Answer 1

Well, if you really really want to do it on the MK, then you buy a real-time sensor (for example, DS1307), a relay, and in the code, respectively, write that the MK takes the time from the sensor and switches the relay every 24 hours. But in general it will be a collective farm, it is better to do it without MK, as described above.

Answer 2

And what prevents you from putting your own clock on the board? And if the whole task of the board is only to switch pumps, then a microcontroller is not needed, only a clock and a bistable relay.

Answer 3

For such a task, even a microcontroller is not needed.
Buy a mechanical timer-socket and a switching contactor in any electrical store (although they only have a dial for a day, after switching for 12 hours for pumps it’s even better)