I have a very simple circuit that uses a hall effect sensor to measure water flow which then in turn sends pulses to GPIO 13 on my PI. Problem is, for some reason the count of pulses is way below what I know the rate of speed of the impeller to be. Has anyone seen this issue? I have a simple setup of the ground direct to the board, the 5 V direct and pulse output through a voltage divider back to the PI. Its odd that I get a good reading, and a pretty consistent on the number of pulses, but its like 5 a minute.... yet the sensor has 4000GPH going through it.... Could my voltage divider be causing this? I am using a 10k and a 4.7k. Any other issues that anyone can think of before I assume a faulty magnet in the housing?