Temperature control and Datalogin

/*
This program is a transcription in C of a Ladder program to control our temperature during the stress test.

Analog Cabinet In
Oximeter (4-20mA)

Digital Cabinet In
Presence Detector

Digital Cabinet OUT
Dor Lock
Sign

Analog Test In
External Temperature 1 - T1 (4-20mA)
External Temperature 2 - T2 (4-20mA)
External Temperature 3 - T3 (4-20mA)
Internal Temperature - Temp (4-20mA)

Digital Test OUT (always the same value)
Resistence 1 - R1
Resistence 2 - R2
Resistence 3 - R3

Nitrogen Freezing - N2

Supervisory parameters
Step - Step for hising the temperature
Cicle - Heat our Freeze
Temperature - Set Point

*/

// Includes
#<stdio.h>

//Declarations Global
float Temperature;
float Temp;
float T1;
float T2;
float T3;

int Res;
int N2;

float Oximeter;
int Detector;

int Lock;
int Fan;
int Sign;

//Functions

//Read and comprare the temperature to the parameters from supervisory
int ReadTemp (int Cicle, float Step){
	printf("/nread the temperature 1 from pt-100 on CLP: ")
	scanf("%f", &T1);
	printf("/nread the temperature 2 from pt-100 on CLP: ")
	scanf("%f", &T2);
	printf("/nread the temperature 3 from pt-100 on CLP: ")
	scanf("%f", &T3);
	printf("/nread the internal temperature from pt-100 on CLP: ")
	scanf("%f", &Temp);
	printf("/n");
	
	switch (Cicle){
		case 1: //heat
			if ((T1+T2+T3)/3 <= Temperature and Temp <= Temperature){
				if ((T1+T2+T3)/3 < Temp + Step){
					return 1;
				}
			}
		case 2: //cool
			if ((T1+T2+T3)/3 >= Temperature and Temp >= Temperature){
				if ((T1+T2+T3)/3 < Temp - Step){
					return 1;
				}
			}
	}
	return 0;
}

char *datetime()
{
    char *array = (char*)malloc(sizeof(char)*25);
    time_t result;
    result = time(NULL);
    sprintf(array, "%s", asctime(localtime(&result)));
    array[25] = '\0';
    return array;
}

//Main Program
int main (){
	//Declarations
	int Cicle;
	int OUT;
	int Start;
	int converg;
	
	float Step;
	
	FILE * fp;
	
	fp = fopen ("file.txt", "w+");
	
	printf("/nread the Oximeter value: ")
	scanf("%f", &Oximeter);
	Oximeter = Oximeter * 4/5 //convert from 4-20 to absule value
	
	do{
		//Oximeter function to lock the doors and star the fan
		if (Oximeter<16 ){
			Fan=1;
			if (Detector = 0){  //needs to add a time at this routine just locks after 2 minutes withot detection
				Lock=1;
			}
		}
		OUT=ReadTemp(Cicle, Step);

		// prints Mon Oct 24 09:39:07 2016-27
		fprintf(fp, "%s-%f/n", datetime(), Temp);
		
		if (OUT = 1  and Cicle = 1) {
			Res = 1;
			N2=0;
		}
		else if (OUT=1 and Cicle=2){
			Res = 0;
			N2=1;
		}
		
		if ((T1+T2+T3)/3 = Temp and Temp = Temperature)
			converg = 1;
		
		
		scanf("%f", &Oximeter);
		Oximeter = Oximeter * 4/5	
	} while Start = 1;
	
	fclose(fp);
	
}
return 0;