Re: can i measure AC voltage with a mcu with only resistance
yes. if you have high voltage such as 110v or 220v you must first reduce it.
and if you don't have ADC and you want to use mcu adc, you must have an offset DC valtage.
you can use AVR MCU such as ATMega32 or ATmega16 Or Atmega8.
Re: can i measure AC voltage with a mcu with only resistance
without aux. ADC or built-in ADC it seems not possible. Bu as a theory, if you know the frequency of AC signal, you can make a R-2R ladder to create a DAC synchrosed with your test signal at zero-crossing. By changing amplitude of DAC output and adding it to test signal, you can find the AC amp. up to 4.7 volts.