Alogrithm of a sine wave using look up table

[MathsLearner]

I am trying to write an algorithm for generating a sine wave using look up table (then i have to write as a program) the max frequency of the sine wave is now [math]1KHz[/math] as a first attempt. Please advise if my algorithm is correct.
Step1: I want to divide the sine wave of period [math]360deg[/math] into [math]1024[/math] samples (I could have chosen another value, but i saw lot of people assuming this value). Hence each step will be [math]\frac {360} {1024} = 0.35deg[/math] and store in an array say [math] sinarray[1024] [/math].
Step2: I will be sampling these at every [math]50uS [/math]. So each degree value will be taken at [math]50uS [/math].
Step3: Let us say i want to now generate a 500Hz signal. It means 2ms to complete 1cycle. To complete [math] 2ms [/math] using [math]50uS [/math], [math]40 [/math] values to be output [math] \frac {(2ms)} {(50uS)} [/math]. So each value corresponds to an angle of [math]\frac {360} {40} = 9Deg [/math]Step4: The index in the [math] sinarray[] [/math]is [math] \frac 9 {0.35} = 25.7 =>26 [/math], so every [math]26th[/math] value to be taken so [math]0,26,52..[/math] etc and repeat.
Step5: If i want to generate a [math]250Hz [/math] signal, then every [math]13th[/math] value to be taken.

 

[Cubist]

Your calculation looks correct to me.

You might find it useful if you produce a single equation that gives the number of samples to skip, say "n", for a desired output frequency. Then you could rearrange the equation in terms of "n" to see what frequency you'll obtain after rounding the "n" value. If the obtained frequency is too far away from the desired, then you'll need to consider ways of improving your algorithm.