I recently did something similar making a simple RTC from a PCF8563 with battery backup provided by a CR2032. I just used a couple of 1N4004 diodes as shown/described in the circuit here.
Seems to work fine for my needs.
I recently did something similar making a simple RTC from a PCF8563 with battery backup provided by a CR2032. I just used a couple of 1N4004 diodes as shown/described in the circuit here.
Seems to work fine for my needs.