I am using Atmel Studio 7 to program my Arduino and am just having an issue setting specific pins to certain voltages. For example, I want to set Pin 4 in PORT C to 2.75 V, how can I do that? I only know how to set them to high (5V) or low (0V).
Or use a processor that has a built in DAC...
" I want to set Pin 4 in PORT C to 2.75 V, how can I do that? I only know how to set them to high (5V) or low (0V)."
If it is always a single discrete voltage for that pin, you might set the pin for 5v and then use an attached pot or voltage divider to supply the desired output voltage.
Google: ‘voltage divider’.
...Just in case it's not clear, the regular Arduino doesn't have true-analog outputs. analogWrite() "fakes it" with PWM. PWM can be low-pass filtered to get analog (although this is often "imperfect").
PWM can control the speed of a motor, dim an incandescent lamp, or it can make an LED appear dim.
The Arduino does have an ADC and a true-analog input.