Relay Board Control

The following components utilise the relay board:

• Refill Control: refilling of fresh water depending on water level
• Feeder Control: stopping flow pumps, skimmer and actuating the feeder
• Water Exchange Control: actuating the external pump for water exchange
• Balling Control: actuating the pumps for mineral dosing

There are two requirements, which ask for a more sophisticated control of the relay board:

• The dosing of minerals needs to be as precise as possible.
• The communication with the board needs to be reinitialised and even reopened after certain periods of time.

The relay board control implements the following features:

• Low level communication via serial port to the board
• Watchdog for reading/writing to serial port
• Semaphores for avoiding conflicting access to relay board
• HW functionality test before executing commands
• Monitoring and repair of relay board states