protection circuit with Zener 5,6V

Hi Marcio,

Using a Zener should have solved the issue, also note that zener is a low current regulator device. If zener did not work for you try using a Potential divider if our output load current is less.

Also why havent you used a Voltage regulator like 7805?

Elaborating more on the source of voltage and where you are using them would have helped me to do more justice to this question

Frist up all check your Zener diode rating, it may have limit voltage to 5.6 V

Hi marco,

Usually the voltage of a zener won't match in real live values. You should use lower than 5V, like 4.7V but you can even go lower as the microcontroller will still reed a one at say 3V.