I am implementing an Hydroponic System that uses two Sensors (EC and pH), I have faced a problem that the readings from the two sensors are interfered greatly while both are powered, but when I switch off one of them then the readings are right.Unfortunately both power and ground pins must be separated from the sensor controller to get the right reading from the other one.Now to do that I have thought of a circuit that may do the trick but i dont know if it will work like that !!
Crosstalk between sensors is usually solved by reading the sensor twice, and using the second reading.No delays or other code between the readings.Another solution could be a (10-100n) capacitor from pin to ground.Need to see a wiring diagram and links to sensors to see if that's possible.Leo..
This is nothing to do with crosstalk, these are electrolytically in contact with the same solution, so must be isolated in order to measure anything meaningful. In fact I suspect the entire Arduino system will need to float for truly accuracte measurement.Given the electrode potentials are unknown I think you need complete isolation with small relays -any semiconductor approach might not work if one sensor has significantly different electrode potentialfrom the other (creating an inadvertent elctrochemical cell between the devices)So I presume you'd need at least s 3PDT relay for GND, power, signal?
Hi Tom,Yes there's a settling time of 1 min or less especially when both are powered.So Switching schematic uploaded in the first post will work correctly ?!My main Question is Is the circuit right electronically ?? Whatever Load is put there Will it (in means of electronics) switch both Power and Ground with no problems ?! Or Am I missing something?!Thanks,