working

Distinguish.c

+#include <stdio.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdint.h>     
+#ifndef  SCNu8
+#define  SCNu8 "hhu"
+#endif
+#include "Distinguish.h"
+
+int main(void){
+	
+	//starting off with actually getting the data and then inputting it
+	//into the function ( void distinguish() ) that does the real work
+
+	printf("enter size of packet \n");
+	int size;
+ 
+	scanf("%d", &size);
+	int test;
+	uint8_t scanned [size];
+	int i = 0;	
+
+	while(i<size){
+		printf("Enter the %dth index of packet data \n", i);
+		scanf("%8x" , &test);	
+		scanned[i] = (unsigned char)test;
+		i++;
+	}
+        printf("\n\n");	
+	Distinguish(scanned); 	//pass reference into real function
+	
+	
+	return 0; //done
+}
+
+
+//	The only real stuff that happens. First I separate the data into respective variables, then
+//identify the message_type either as display motor or neither (fail). Create input data from rest to 
+//be inputted and call correct function.
+//
+//Input:  Array pointer to unsigned bytes (uint8_t *array)
+//Output: Prints an error statement IF the message type isn't recognized
+
+
+void Distinguish(uint8_t *data){
+	
+	uint8_t packet_id = *data;
+	uint8_t message_type = *(data+1);
+	uint16_t message_length = *(data+2);     		// grouping useful data 
+	
+	if(message_type == 0x34){				 //messagetype = display
+		char message_message [message_length];
+		int i = 0;
+		for(i = 0; i< message_length; i++){
+			message_message[i] = *(data+i + 4);      //loop through data to creat string
+		}
+		display_message(message_message, message_length);
+	} 
+	else if(message_type == 0x80){				 //messagetpye = motor
+		int32_t forwardback=0;
+		int32_t leftright = 0;
+		for(int i=0; i<4; i++){ 			 //loop places data bytes into right
+			forwardback += *(data+4+i);		 //spot
+			leftright   += *(data+8+i);
+			if(i!=3){
+			leftright = leftright << 8;
+			forwardback = forwardback << 8;          // left shift a byte except for last
+			}
+		}
+		update_motor(forwardback, leftright);
+	}
+	else{
+		printf(" unknown message_type \n");
+		return;
+	}
+
+	return;
+}
+
+
+void display_message(char *message, uint16_t message_length){
+
+	printf(" display_message() was called \n" );
+	printf(" message: ");
+	int i = 0;
+	for(i=0; i<message_length; i++){
+		printf("%c",message[i]);
+	}
+	return;
+}
+
+void update_motor( int32_t fowardback, int32_t leftright){
+
+	printf(" update_motor() was called \n");
+	printf(" Forward_back = %d \n", fowardback);
+	printf(" Left_Right = %d \n", leftright);
+	return;
+}

Distinguish.h

+#ifndef DEFINE
+
+
+void Distinguish(uint8_t *data);  //real function that is tested
+
+void display_message(char* message, uint16_t message_length);   //called if display message type
+
+void update_motor( int32_t fowardback, int32_t leftright); //called if update_motor type
+
+
+
+
+#endif

Makefile

+CC = gcc
+CFLAGS = -I
+LDFLAGS = -lm
+
+.PHONY: all
+all: test
+test: Distinguish.o
+	$(CC) -o test Distinguish.o
+
+
+ 
+clean:
+	rm -f *.o test

README.md

@@ -2,8 +2,9 @@ This is the code submission for Elliot Couvignou
 
 To run this program all you need to do is:
 
-1. type /make to compile
+1. type make to compile (in the correct directory)
 2. type ./test to begin
 3. enter the packet data to distinguish (uint8_t 1D array)
 4. check my result :).
 
+if for some reason things dont work try /make clean and repeat the steps.