Howdy,



        I am interested in finding some information for a PIC project.

        Is there a sensor that can measure pH that is cheapish and can
        say be connected to a PIC (similar to a DS1820 temp chip)?

        Also, is there a sensor which can measure the amount of CO2 gas
        in a given area?? again, it would be good to connect this to a PIC
        chip.

        The reason is that I am interested in starting a little hydroponics
        set up, and any information on these (including the hydroponics :-))
        would be of great help.


Regards,


Rob Walker.