10 Replies Latest reply on Aug 10, 2014 7:31 AM by JoMe_264151

    measuring electrical signals

    feme_285141

       hola a todo nesecito tomar datos de señales en el orden de la 200mV con ocho canelales diferentes pero las señales que quiero regitrar solo tradan 5 ms como podria tomar esto dato con psoc? soy nuevo en esto.

        • 1. Re: measuring electrical signals
          feme_285141

           hello to all nesecito take data signals in the order of 200mV with eight different signals canelales but I want regitrar tradan only 5 ms and could take this data with psoc? I'm new to this.

          • 2. Re: measuring electrical signals
            JoMe_264151

            A PSoC4 has got an SAR with up to 1 Msps (Million samples per second) with a resolution of 12 bits and can use an 8 channel analog multiplexer. So your required 5ms will be no problem.

               

            The conversion range is 0 to 1024mV, so your effective precision is 9 to 10 bits. When that is good enough for you I would suggest you to get hands on a Pioneer Kit CY8C-049, look here www.cypress.com/. It will give you the ability for prototyping and debugging your projects.

               

             

               

            Bob

            • 3. Re: measuring electrical signals
              JoMe_264151

              Ooops, I just see that you are questioning for a PSoC5 solution. The PSoC5 is quite more capable,but the development kit more expensive secure.cypress.com/

                 

               

                 

              Bob

              • 5. Re: measuring electrical signals
                feme_285141

                 I'm doing a thesis on a plant called mimosa pudica that when touched generates an electrical impulse that causes the leaves cierre.Pues as I live in Panama there is no equipment to measure electrical impulse that so I decided to use a microcontroller and investigating met the mucho.Como psoc and I like my thesis is to measure the electric imposed eight different part of the so planata to analyze data that concerns me is the amount of sample taken in quickly .I psoc have one?: cy8c29466-24pxi, psoc four pioneer CY8CKIT-050 and I'm PSoC® 5LP convinar thinker as any since psoc 1 has amplier intrumentales nesecito and filters. what worries me is the adc.

                • 6. Re: measuring electrical signals
                  JoMe_264151

                  ADC specs for DELSIG www.cypress.com/

                     

                  SAR specs www.cypress.com/, both from PSoC5LP.

                     

                   

                     

                  Bob

                  • 7. Re: measuring electrical signals
                    DaKn_263916

                    There are some additional considerations.

                       

                     

                       

                    If the plant response is 5 ms and you want to detect its peak response either

                       

                    you have to oversample the 5 ms response pulse or use a peak detection scheme.

                       

                    Add on top of this you want to examine 8 plants simultaneously ?

                       

                     

                       

                    As example lets say we oversample by factor 5, and do 8 plants, then we have

                       

                    5 mS / ( 5 * 8 ) = 125 uS, 8000 SPS, certainly within range of DelSig or SAR. Peak

                       

                    detection done in code for each channel. Delsig would give you buffer gain capability

                       

                    and 14 - 15 bit resolution.

                       

                     

                       

                    Sequencing SAR certainly would do this to 12 bit resolution.

                       

                     

                       

                    Or use peak detector, take a look at this -

                       

                     

                       

                        

                       

                              http://www.cypress.com/?rID=41001

                       

                     

                       

                    Although muxing the peak detector would have to be evaluated in terms of settling

                       

                    time to desired resolution.

                       

                     

                       

                    Regards, Dana.

                    • 8. Re: measuring electrical signals
                      JoMe_264151

                      By the way:

                         

                      I have learnt (some years ago) that the signalling for this plant is done by a chemical substance and not by electric connections like in animal nerves. The substance acts on certain cells which alter their size by soaking water into and so move the leaves of the branch instantly.

                         

                      Are there any new / other perceptions within the last 20 years?

                         

                       

                         

                      Bob

                      • 9. Re: measuring electrical signals
                        feme_285141

                         well what happens is an exchange of ions between the cell which gives the result to an osmosis that leaves the cell with almost no water and therefore the cell walls do not have the strength to stand and therefore the ground moves devido gravity and has no strength to stand. In reliza what I measure is concentration of ions through the electrode becoming just electric pulse. For this reason and more; today shown great debates that if the plant have the same perception that animal.

                        • 10. Re: measuring electrical signals
                          JoMe_264151

                          Thanks for that clarification! ...always learning...

                             

                           

                             

                          Bob