diff --git a/Project/applications/smartcities/include/json.h b/Project/applications/smartcities/include/json.h
index bb2627a..2c53d93 100644
--- a/Project/applications/smartcities/include/json.h
+++ b/Project/applications/smartcities/include/json.h
@@ -1,14 +1,17 @@
 #ifndef JSON_H
 #define JSON_H
 
+#include <string.h>
+#include <stdint.h>
+
 #define	JSON_POST_OK		0
 #define	JSON_COMM_ERROR		1
 #define JSON_OTHER_ERROR	2
 
-char* prepare_json_statement(char* data, uint32_t length);
+char* prepare_json_statement(char** data, uint32_t nObservations);
 char* prepare_observation(char* observation, uint32_t length);
 uint8_t send_json(char* statement, uint32_t length);
 uint32_t find_next_index(char* string, uint32_t length, char delimiter);
-char* join_strings(char* str1, char* str2, uint32_t len1, uint32_t len2)
+char* join_strings(char* str1, char* str2, uint32_t len1, uint32_t len2, bool)
 
 #endif
diff --git a/Project/applications/smartcities/json.c b/Project/applications/smartcities/json.c
index 76ee66e..03c9a5f 100644
--- a/Project/applications/smartcities/json.c
+++ b/Project/applications/smartcities/json.c
@@ -1,11 +1,30 @@
-char* prepare_json_statement(char* data, uint32_t length)
+#include "json.h"
+
+char* prepare_json_statement(char** data, uint32_t nObservations)
 {
 
 }
 
 char* prepare_observation(char* observation, uint32_t length)
 {
-
+	char *json_data, *str_aux, *str_aux2;
+	int value_length = find_next_index(observation,length,',');
+	int timestamp_length = length - (value_length + 1);
+	char *value = (char*) chHeapAlloc(NULL,value_length+1);
+	char *timestamp = (char*) chHeapAlloc(NULL,timestamp_length+1);
+	strncpy(value,observation,value_length);
+	strncpy(timestamp,observation+(value_length+1),timestamp_length);
+	value[value_length] = '\0';
+	timestamp[timestamp_length] = '\0';
+	str_aux = join_strings("{\"value\":\"",value,10,value_length,0);
+	str_aux2 = join_strings(str_aux,"\",\"timestamp\":\"",10+value_length,15,0);
+	str_aux2 = join_strings(str_aux2,timestamp,25+value_length,timestamp_length,1);
+	json_data = join_strings(str_aux2,"\"}",25+value_length+timestamp_length,2,0);
+	chHeapFree(str_aux);
+	chHeapFree(str_aux2);
+	chHeapFree(value);
+	chHeapFree(timestamp);
+	return json_data;
 }
 
 uint8_t send_json(char* statement, uint32_t length)
@@ -31,14 +50,18 @@ uint32_t find_next_index(char* string, uint32_t length, char delimiter)
 	return -1;
 }
 
-char* join_strings(char* str1, char* str2, uint32_t len1, uint32_t len2)
+char* join_strings(char* str1, char* str2, uint32_t len1, uint32_t len2, uint8_t free_mem)
 {
 	char* str = (char*) chHeapAlloc(NULL,len1+len2+1);
-	/*strcat(str,str1);
-	strcat(str,str2);
-	USAR STRNCAT
-	*/ 
-
+	strncpy(str,str1,len1);
+	str[len1] = '\0';
+	strncat(str,str2,len2);
+	if(free_mem)
+	{
+		free(str1);
+		free(str2);
+	}
+	return str; 
 }
 
 /*