How to store a number in decimal format in avr

Question

I am trying to enter the decimal values using a keypad in ATMega8 Till now I have been able to enter only the integer values The code is given below

switch (         


        

Answer 1

Its basic high school math, you need represent numbers in powers of 10.

Example - 
138.25 = (1 * 10^2) + (3 * 10^1) + (8 * 10^0) +         // integer part
         (2 * 10^-1) + (5 * 10^-2)                      // Float part

I will not give you complete code, but you can use this idea

if (decimal)
{
    a = a + b / (10 ^ pow);
}
else
{
    a = a * 10 + b
}

pow is the decimal digit - In above example (138.25) pow 2 is 1, and pow for 5 is 2. So you need to maintain counter for pow