[SeanHodgins] has a project in mind where he needs to sample over 500 analog ... digital pins to control the device. The device in question is an ADG732. The board layout and the source code ...

But what exactly are these PWM pins, and how do you use them? The Arduino Mega's PWM pins are digital output ... One is using an analog input like a potentiometer. In this case, the analogWrite ...

A potentiometer ... the analog output (AO) of the module, to one analog input (A0) of the Arduino. Here is the test code that indicates the soil wet/dry conditions using just two LEDs (green & red).