Question

The value read at an analog input pin using analogRead() is returned as a binary number between 0 and the maximum value that can be stored in [X] bits. 1. This binary number is directly linearly proportional to the input voltage at the analog pin, with the smallest and largest numbers returned corresponding to the minimum and maximum ADC input values, respectively. At a Vcc of 3.3 V, analogRead(A0) returns a value of 1023. Approximately what voltage is present at the pin A0 on the MSP430F5529?

Answer 1

Answer: The approximate voltage would be the result from computing analogRead(A0)*3.3 V / 1023

Explanation:

Depending on the binary read of the function analogRead(A0) we would get a binary value between 0 to 1023, being 0 associated to 0V and 1023 to 3.3V, then we can use a three rule to get the X voltage corresponding to the binary readings as follows:

3.3 V ---------> 1023

X  V------------>analogRead(A0)

Then $X=\frac{3.3 \times analogRead(A0)}{1023} Volts$

Thus depending on the valule analogRead(A0) has in bits we get an approximate value of the voltage at pin A0, with a precission of 3,2mV approximately (3.3v/1023).