Reply To: PH Sensor Issue

The way a voltage divider works is for you to use 2 resistors in series, and then you measure the junction between the two resistors, and you’ll see a fraction of the overall voltage. The best method for breaking a 5v signal down to something the Mayfly can tolerate would be to use two identical value resistors (like 10k-ohms each), so that way the point your measuring is exactly half of the overall voltage, hence the *2 multiplication in my formula above. You can use any ratio you want, but a pair of identical resistors is easiest for your first voltage divider.