The K28 Flow Controller is used to control the pump speed of a submersible brushless DC pump. It is a product replacement for the Crayfish Controller. The controller is powered by a 12V or 24V DC desktop adapter, or universal battery for use in the field. It passes DC power to the pump and controls the pump speed, and the flow rate of the water into our Emriver models, using an analog voltage output. The knob/button combination is used to adjust the flow rate or quickly set it to 0. It features a clear lid to view the internals and the power and pump LEDs.

I designed the circuit board and wrote the software for the instrument's operation in Arduino C++. I've had a few iterations of the board to improve quality, reduce production costs, and simply the device assembly.