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I'm going to use a very precise potentiometer that can measure angles from 0 to 3600 degrees (10 rounds), but I only need the first 180 degrees or so in this project and I need it to be more precise than 3600/1024=3,52 degrees. I thought about connecting the pot to 5v and setting analog reference to INTERNAL (1.1V on Uno r3) so I can measure the first 1.1V with enough precision. My question is if this will damage my Arduino if the pot accidentally gives more than 1.1V. It will never increase 5V though. I have read multiple answers on the internet but I don't know who to trust. I want an answer of someone who knows what he's talking about. Will supplying up to 5V damage with analog reference set to 1.1V?


marked as duplicate by PeterJ, user17592, Ignacio Vazquez-Abrams, Dave Tweed Nov 30 '14 at 13:02

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


Whenever, you should trust the MCU's datasheet. In ATmega328's (which MCU Uno use) datasheet, p. 313, it states:

Voltage on any Pin except \$\overline{RESET}\$ with respect to Ground ...............................-0.5V to VCC+0.5V

Note: "VCC" means the voltage on your MCU's VCC pin, if you MCU's VCC is 0V, your ADC's input shouldn't beyond 0.5V (this may appear when your system is powering on).


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