12 Replies Latest reply on Oct 25, 2013 6:03 AM by user_200706552

    Simple DDS [State Variable, IIR]


      Here is a DDS approach another poster turned me on to, very fascinating.




      Think State Variable, second order, 2 integrators + sign change = oscillator. Or think


      second order IIR with positive feedback.




      Runs just from C code, 80 uS ( 12.5 Khz ), 40 samples/sine.




      With optimization, conversion to fixed point, binary size elements, ASM vs C, or HW solution,


      should yield much higher freq.




      Add a timer to control code placed in ISR, eg.  sample period, or just use a delay function to control sample rate.




      Regards, Dana.