Question

What does the command Value = 2.0*analogRead(A1)/512.0 do? a) Reads an analog signal from pin A1 and doubles its value

b) Scales the analog input from pin A1 to a value between 0 and 2
c) Converts the analog input from pin A1 to a floating-point number between 0 and 1
d) Adjusts the analog signal from pin A1 to a value between 0 and 512

Answer 1

The command scales the analog input from pin A1 to a value between 0 and 2 by reading the analog value, doubling it, and then dividing by 512.0, resulting in a floating-point number within the specified range.

Step-by-step explanation:

The command Value = 2.0*analogRead(A1)/512.0 performs several operations:

• It calls the analogRead() function on pin A1 to read the analog voltage level, which returns a value between 0 and 1023 (assuming a 10-bit analog-to-digital converter).
• The read value is then multiplied by 2.0, effectively doubling it.
• Finally, the doubled value is divided by 512.0, which scales the original analog read value down by a factor of 256 and converts it to a floating-point number.

The correct answer to the student's question is therefore b) Scales the analog input from pin A1 to a value between 0 and 2. The command does not simply double the value of the analog signal, nor does it adjust it to a range between 0 and 512. It also does not convert the signal to a range between 0 and 1.