I want to build a device for measuring pH, TDS/Ec, ORP and temperature using Arduino. Can you help me with a diagram and sketch? Perhaps you have already seen the finished product somewhere? I will be very glad if you help me
There are Fritzing parts for PH and TDS (I have no idea if it also does Ec), I have no idea what ORP is and there are a variety of temperature sensors available. In general a google search of the form "fritzing part part number: (where part number is the part you need) will find Fritzing parts that people have made. Good luck.
Peter