2 Replies Latest reply on Aug 23, 2014 6:03 AM by user_14586677

    IRIG-B demodulation/decoding

    charles.hermann

       Hello:

         

      I have no experience with PSoC devices, but suspect this will be a perfect platform for a new project I am working on. I need to demodulate and decode a IRIG-B 12x AM  time code signal.It uses a 1khz carrier. It encodes with a mark to space ratio of 10/3 and uses pulse width coding (10 cycles of the carrier represents an index count interval) 80% duration mark is a reference pulse 50%duration of the mark is a binary 1 and 20% is a binary 0. I wonder if anyone on this forum has used these devices for any thing of the sort . Any assistance will be appreciated.

         

       

         

      Thanks,

         

       

         

      C. Hermann

        • 1. Re: IRIG-B demodulation/decoding
          user_1377889

          Welcome in the fascinating world of PSoCs!

             

          It does not sound too difficult, there are plenty of counters and timers availlable within a PSoC5 all equipped with a capture function. The ARM cortex m3 is fast enough to handle interrupts with 1kHz frequency.

             

          Counting the pulse-width of a 1 kHz signal can be done mostly in hardware.

             

          To start with I would suggest you to get hands on an evaluation kit as this secure.cypress.com/. It gives you debug-capabilities as setting breakpoints and inspecting variables. Additionally you need the Creator software that you may download (Free, just registration) from the Cypress website here secure.cypress.com/psoccreator/.

             

          Lastly there is a whole bunch of videos showing how to get acquainted to "Thinking PSoC".

             

           

             

          Bob

          • 2. Re: IRIG-B demodulation/decoding
            user_14586677

            I have seen HW and SW only solutions on the web to do the decode.

               

             

               

            Basic info here               http://www.irigb.com/IRIGB_standard.html

               

             

               

            Timing does not look too critical. Peak detection in PSOC simple as well as

               

            period counting. Maybe even a LUT to control most of the activity. On e

               

            complication is possibilitry there is a need for an AGC loop, but there are

               

            many methods to handle that.

               

             

               

            Regards, Dana.