diff --git a/common/auxiliar.c b/common/auxiliar.c
index 9adbb20..8230ad4 100644
--- a/common/auxiliar.c
+++ b/common/auxiliar.c
@@ -120,4 +120,44 @@ void normalize(char **inputs, int num_inputs)
                         }
                 }
         }
+}
+
+int bin2dec(char *bin)
+{
+        int i;
+        int num = 0;
+        int length = strlen(bin);
+        int pos = length - 1;
+        char *aux = (char*) malloc(sizeof(char) * length);
+        strcpy(aux,bin);
+        normalize(&aux,1);
+        for(i = 0; i < length; i++)
+        {
+                if(aux[pos--])
+                {
+                        num += pow(2,i);
+                }
+        }
+        free(aux);
+        return num;
+}
+
+char* dec2bin(int dec, int length)
+{
+        char *bin = (char*) malloc(sizeof(char) * length + 1);
+        int pos = length-1;
+        int i;
+        for(i = 0; i < length; i++)
+        {
+                if(dec & 0x1)
+                {
+                        bin[pos--] = '1';
+                }
+                else
+                {
+                        bin[pos--] = '0';
+                }
+                dec >>= 1;
+        }
+        return bin;
 }
\ No newline at end of file
diff --git a/common/auxiliar.h b/common/auxiliar.h
index b3eb016..1633f57 100644
--- a/common/auxiliar.h
+++ b/common/auxiliar.h
@@ -13,3 +13,5 @@ void error();
 void free_mem(char **inputs, int num_inputs);
 
 void normalize(char **inputs, int num_inputs);
+int bin2dec(char *bin);
+char* dec2bin(int dec, int length);
\ No newline at end of file
diff --git a/plexers/Makefile b/plexers/Makefile
index 3229256..69be5b7 100644
--- a/plexers/Makefile
+++ b/plexers/Makefile
@@ -1,4 +1,4 @@
-TARGETS = multiplexor
+TARGETS = multiplexor demultiplexor encoder decoder
 
 .PHONY: all clean
 
@@ -9,3 +9,11 @@ clean:
 
 multiplexor:
 	gcc -I../common/ ../common/auxiliar.c multiplexor.c -o multiplexor -lm
+
+demultiplexor:
+		gcc -I../common/ ../common/auxiliar.c demultiplexor.c -o demultiplexor -lm
+
+encoder:
+		gcc -I../common/ ../common/auxiliar.c encoder.c -o encoder -lm
+decoder:
+		gcc -I../common/ ../common/auxiliar.c decoder.c -o decoder -lm
diff --git a/plexers/decoder.c b/plexers/decoder.c
new file mode 100644
index 0000000..0b193cd
--- /dev/null
+++ b/plexers/decoder.c
@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <string.h>
+#include "auxiliar.h"
+#include <math.h>
+
+int main(int argc, char **argv)
+{
+	int i;
+	if(argc != 2)
+	{
+		error();
+	}
+	char *input = argv[1];
+	if(!strcmp(input,"error"))
+	{
+		error();
+	}
+	char **inputs = comma_separate(input);
+	if(inputs == NULL)
+	{
+		error();
+	}
+	int num_inputs = num_occurrences(input,',');
+	if(num_inputs != 1)
+	{
+		error();
+	}
+	int selected = bin2dec(inputs[0]);
+	int num_outputs = pow(2,strlen(inputs[0]));
+	for(i = 0; i < num_outputs; i++)
+	{
+		if(i == selected)
+		{
+			printf("1");
+		}
+		else
+		{
+			printf("0");
+		}
+		if(i != (num_outputs-1))
+		{
+			printf(",");
+		}
+	}
+	free_mem(inputs,num_inputs);
+	return 0;
+}
diff --git a/plexers/demultiplexor.c b/plexers/demultiplexor.c
new file mode 100644
index 0000000..78547d1
--- /dev/null
+++ b/plexers/demultiplexor.c
@@ -0,0 +1,52 @@
+#include <stdio.h>
+#include <string.h>
+#include "auxiliar.h"
+#include <math.h>
+
+int main(int argc, char **argv)
+{
+	int i;
+	int j;
+	if(argc != 2)
+	{
+		error();
+	}
+	char *input = argv[1];
+	if(!strcmp(input,"error"))
+	{
+		error();
+	}
+	char **inputs = comma_separate(input);
+	if(inputs == NULL)
+	{
+		error();
+	}
+	int num_inputs = num_occurrences(input,',');
+	if(num_inputs != 2)
+	{
+		error();
+	}
+	int input_length = strlen(inputs[0]);
+	int selected = bin2dec(inputs[1]);
+	int num_outputs = pow(2,strlen(inputs[1]));
+	for(i = 0; i < num_outputs; i++)
+	{
+		if(i == selected)
+		{
+			printf("%s",inputs[0]);
+		}
+		else
+		{
+			for(j = 0; j < input_length; j++)
+			{
+				printf("0");
+			}
+		}
+		if(i != (num_outputs-1))
+		{
+			printf(",");
+		}
+	}
+	free_mem(inputs,num_inputs);
+	return 0;
+}
diff --git a/plexers/encoder.c b/plexers/encoder.c
new file mode 100644
index 0000000..c0086f2
--- /dev/null
+++ b/plexers/encoder.c
@@ -0,0 +1,68 @@
+#include <stdio.h>
+#include <string.h>
+#include "auxiliar.h"
+#include <math.h>
+
+int check_length(char **inputs, uint8_t num_inputs)
+{
+    int i;
+    for(i = 0; i < num_inputs; i++)
+    {
+            if(strlen(inputs[i]) != 1)
+            {
+                    return -1;
+            }
+    }
+    int max_value = 1;
+    i = 0;
+    while(max_value < num_inputs)
+    {
+    	max_value = pow(2,++i);
+    }
+    return i;
+}
+
+int main(int argc, char **argv)
+{
+	int i;
+	int pos;
+	if(argc != 2)
+	{
+		error();
+	}
+	char *input = argv[1];
+	if(!strcmp(input,"error"))
+	{
+		error();
+	}
+	char **inputs = comma_separate(input);
+	if(inputs == NULL)
+	{
+		error();
+	}
+	int num_inputs = num_occurrences(input,',');
+	pos = num_inputs - 1;
+	int sel_length = check_length(inputs,num_inputs);
+	if(sel_length == -1)
+	{
+		error();
+	}
+	int selected = -1;
+	for(i = 0; i < num_inputs; i++)
+	{
+		if(inputs[i][0] == '1')
+		{
+			selected = i;
+			break;
+		}
+	}
+	if(selected == -1)
+	{
+		error();
+	}
+	char *result = dec2bin(selected,sel_length);
+	printf("%s",result);
+	free(result);
+	free_mem(inputs,num_inputs);
+	return 0;
+}
diff --git a/plexers/multiplexor b/plexers/multiplexor
deleted file mode 100755
index 181bc09..0000000
--- a/plexers/multiplexor
+++ /dev/null
diff --git a/plexers/multiplexor.c b/plexers/multiplexor.c
index 0d8dde0..1207657 100644
--- a/plexers/multiplexor.c
+++ b/plexers/multiplexor.c
@@ -3,26 +3,6 @@
 #include "auxiliar.h"
 #include <math.h>
 
-int bin2dec(char *bin)
-{
-	int i;
-	int num = 0;
-	int length = strlen(bin);
-	int pos = length - 1;
-	char *aux = (char*) malloc(sizeof(char) * length);
-	strcpy(aux,bin);
-	normalize(&aux,1);
-	for(i = 0; i < length; i++)
-	{
-		if(aux[pos--])
-		{
-			num += pow(2,i);
-		}
-	}
-	free(aux);
-	return num;
-}
-
 int check_length(char **inputs, uint8_t num_inputs)
 {
         int i;
diff --git a/todo b/todo
index 970a6f4..3088924 100644
--- a/todo
+++ b/todo
@@ -1,6 +1,3 @@
-demuxer
-coder
-decoder
 bit selector
 
 adder