I have a 3.3V circuit with an ADC chip that reads values between 0V and 2.1V, that means anything above 2.1V will return 2047. If I use a voltage divider with the Vcc power supply, I would lose a lot of range. What is the best solution to measure all values? Do I have to buy a 2.1V regulator? Or can I supply 2.1V with another voltage divider?
The variable resistor in that provides the voltage to measure would be a potentiometer or a light sensor (photoresistor).