4 Replies Latest reply on Oct 17, 2011 2:33 PM by philip.nielsen

    SPI Code example for PSOC1

    philip.nielsen

      I am using the PSoC 1 CY29466 MCU. I discovered the internal ADC do not have enough resolution or linearity  for my project. I decided to use ADS1211 ADC. It takes a three wire SPI interface. Can you point me in a direction for examples to write and read from the external ADC?

         

       

         

      Thank You,

         

       

         

      Philip

        • 1. Re: SPI Code example for PSOC1
          pmad

           Hello Philip,

             

           

             

          I agree that the ADC provided does not have good resolution and it introduces some offset but there are a few app notes available which employees a technique called Correlated Double Sampling (CDS) to measure the signal. App not available here: http://www.cypress.com/?rID=2894 explains that method in detail with an example of how to measure signal of a thermocouple, where resolution required is as low as 40uV.

             

           

             

          If you want some code examples for SPI then let me know your email address, I shall be able to send you the projects.

             

           

             

          Best regards,

             

          Pushek

          • 2. Re: SPI Code example for PSOC1
            philip.nielsen

            I would love help on SPI code. I spent the weekend looking for SPI code to a ADS1211 ADC. I received some nice responses and some responses that should be put in the nasty list. If I can make the 13 bit linear that would be great. I will eventualy need to solve the SPI code problem.

               

             

               

            Thank You,

               

             

               

            Philip

            • 3. Re: SPI Code example for PSOC1
              philip.nielsen

              Would it be very difficult to creat a SPI code and .h file to communicate with the TI ADS1211?

                 

               

                 

              Thank You,

                 

               

                 

              Philip

              • 4. Re: SPI Code example for PSOC1
                philip.nielsen

                I did look at the app note. It would not open. It complained about a cmx problem. I opened the main.C file. Even if I could get my 13 bit AD working with 0% error. The best I could acheive would be +/- .0006. This is marginal. My custumer wants x.xxx. So I am forced into using a high accuracy ADC IC. Do you have any sampls of SPI code talking to ADCS? I am stumped on the SPI code.

                   

                 

                   

                Thanks

                   

                 

                   

                Philip