/////////////////////////////////////////
// Example of comparator using UDP Table for smart irrigation system (trustworthy event detection)
/////////////////////////////////////////
///Here we are using three different variables for four different sensors and two outputs one for 
///the actual output for an event and one for the flage (i.e., Gray Code).
///We use Intel Core i7, 16 GB RAM, Win 10,
/// 64 Bit OS. We utilised the latest version of the Icarus Verilog iverilog-0.9.7 (latest stable release) for PLD programming, and 
///  GTKWave (version 3.3.104)

`timescale 1ns / 1ps
module comparator(
	input AirTemperature,
	input SoilTemprature,
	input AirHumidity,
	input SoilMoisture,
	output Output,
	output [2:0] Flag
		
);
compare c0(Output, AirTemperature, SoilTemprature, AirHumidity, SoilMoisture);

compare2 c20(Flag, AirTemperature, SoilTemprature, AirHumidity, SoilMoisture);

endmodule

///The below logic table is used for the logic gate design
 
primitive compare(Output, in1, in2, in3, in4);
	output Output;
	input in1,in2,in3, in4;
table
// in1  in2  in3  in4: out
    0    0    0  0	 :  0; 
    0    0    0  1	 :  0; 
    0    0    1  0	 :  0; 
    0    0    1  1	 :  1; 
	0    1	  0  0	 :  0;
	0    1    0  1	 :  1;
	0    1    1  0	 :  1; 
	0    1    1  1	 :  1;
	1    0    0  0	 :  0; 
    1    0    0  1	 :  1; 
    1    0    1  0	 :  1; 
    1    0    1  1	 :  1; 
	1    1	  0  0	 :  1;
	1    1    0  1	 :  1;
	1    1    1  0	 :  1; 
	1    1    1  1	 :  1;
	
endtable
endprimitive

/// The below logic table is used for the Flag (i.e, Gray Code), it also transfer the status of all sensors such as which sensor or variables participate in the output

primitive compare2(Flag, in1, in2, in3, in4);
	output Flag;
	input in1,in2,in3, in4;
table
// in1  in2  in3  in4: out
    0    0    0  0	 :  0; 
    0    0    0  1	 :  1; 
    0    0    1  0	 :  1; 
    0    0    1  1	 :  1; 
	0    1	  0  0	 :  1;
	0    1    0  1	 :  1;
	0    1    1  0	 :  1; 
	0    1    1  1	 :  1;
	1    0    0  0	 :  1; 
    1    0    0  1	 :  1; 
    1    0    1  0	 :  1; 
    1    0    1  1	 :  1; 
	1    1	  0  0	 :  1;
	1    1    0  1	 :  1;
	1    1    1  0	 :  1; 
	1    1    1  1	 :  1;
	
endtable
endprimitive