After much deliberation the winner for the Get your next project sponsored by us contest is Murray Harms from Queensland Australia. His idea was to develop a system to help him manage his fish farm.

in his words...

Aquaculture System Controller.

Overview
The proposed project is to construct a controller for an automated self cleaning filtration system for a commercial Recirculating Aquaculture System (RAS). The proposed RAS system consists of a number of culture tanks, which share a self cleaning filter system between 2 tanks. Briefly the filter system is the first stage of filtration in the RAS, which mechanically filters the heavy solids from the culture water via a settling sump followed by a screen filter for the finer, suspended solids. The controller is designed to automatically trigger the rinse cycles to flush the solids from the sump and the screen filters.

The filtration system is also fitted with sensors for monitoring water levels, flow rates and other key water quality parameters associated with each culture tank. Importantly, the controller is designed to act as a data logger to log data to a central system (via Ethernet) – if connected – or provide some limited storage locally to store and forward the data.

Theory of Operation
The system is designed as a stacked set of boards (prototype system has only 3), each board having a 4 way DIP switch to provide a settable ID for the board, expandable to 16. The Master board is the Ethernet controller – responsible for comms with the central computer system and driving the human feedback devices (LCD display and status LEDs) and reads inputs from switches which provide the manual override (manual flush, open valve etc).

The slave board(s) act as the primary I/O device(s) for reading the sensors – providing the signal conditioning and triggering the outputs for the rinsing pumps and valves. (Note that an external relay switching package will be used for the mains power switching). The slave board(s) connects to the master board via stacking header(s), with comms achieved via a simple serial protocol.

Given that some of the sensors are critical alarms, some self test and redundancy will be built in to provide positive feedback that the board is functional and the IO lines are acting correctly.

Thanks to all who entered and congratulations to Murray.