Hi..
If i'll give a analog input in form of voltage( let 5 volt) to a Arduino Board through analog pin A0 , and if we'll use the codeanalogread(0) then what it'll give?
It'll give 5 or something else.
It will give 1023. See http://arduino.cc/en/Reference/AnalogRead.
Actually sir I have one circuit(Buck converter) and I want to fix its output voltage .
To do this I am using the PID controller code for generating PWM , by giving the reference of the voltage what I want in the output and taking the actual output voltage of circuit and giving to the Arduino analog input .
My doubt is that , how it'll work, if analogread(0) will give 1024 ?
If the voltage you want to measure may go above 5V then you need to use a voltage divider (2 resistors) to reduce it to a suitable range. For example, if you connect a 10K resistor between the output of your buck converter and an Arduino analog input, and another 10K resistor between the input and ground, then you will get a reading of 512 when the converter is producing 5V, and it would have to go to nearly 10V to get a reading of 1023. Then setting your PID controller to have a target of 512 should give you 5V output. This all assumed that the Arduino itself has a stable +5V supply independent of the buck converter output.