The Scenario FIGURE $1$ shows part of a control system used to maintain the water level in a sump between the levels high and low. Two transducers $($HIGH and LOW$)$ are used to monitor the level. The water is pumped out by two pumps, P$1$ and P$2.$ The water level in the sump is to be controlled as follows: $$

If the level reaches high one pump will start to pump out. $$

If the level does not reach low within about $30$ seconds, the second pump will come into action. If the level does reach low before $30$ second pumping should stop. $$

If the level does not reach low within about $30$ seconds of the second pump starting, an alarm is given. The alarm is sounded until the level reaches low. If the level does reach low before $30$ seconds the pumping should stop. $$

The pumps will stop when low is detected. $$

To give even loading of the pumps they are to be used alternately, e$.$g$.$ if on one pump cycle P$1$ starts first and P$2$ is the $$back up$$ then on the next cycle P$2$ will start first and P$1$ is the $$back up$.$

The system is to be controlled by an Arduino microcontroller. The pumps can be mimicked by LEDs$*.$ Switches can be used to represent the LOW and HIGH transducers. The program should inspect the input switches at regular intervals and take appropriate action.

$*$If you chose to use the UnoArduSim then you can use its motor simulators to model the two pumps. A further enhancement would be to use a potentiometer as a $$level$$ transducer so that, say, $10\%$ travel is $$low level$$ and $90\%$high level$.$

PROGRAM SPECIFICATION

It is obvious that before starting to design and code a computer program, the programmer should have all the relevant information required to solve the problem. This information should include:

$$ what operation the program is expected to perform

$$ details of input data that will be used

$$ an indication of the expected output

$$ any additional information such as mathematical formulae to be used, as well as any hints that would help in the solution.

rIG. All this information forms the PROGRAM SPECIFICATION.