Revision 13:b44c1f678aff, committed 2017-10-22

Comitter:

Cheroukee

Date:

Sun Oct 22 20:20:42 2017 +0000

Parent:

12:e21604b50719

Commit message:

Needs testing, added CRC calculations and adapted queue code to work with radio

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crc.cpp	Sun Oct 22 20:20:42 2017 +0000
@@ -0,0 +1,43 @@
+
+#include "crc.h"
+
+#define POSSIBLE_VALUES 256
+
+char crc_table[POSSIBLE_VALUES];
+
+void init_crc_module()
+{
+    /* iteration sur toutes la valeurs possible de CRC pour le valeurs de byte possible */
+    for (int i = 0; i < POSSIBLE_VALUES; i++)
+    {
+        char current_byte = (char)i;
+        /* calcul de la valeur de CRC pour le byte actuel a l'aide des operations bit a bit avec XOR */
+        for (char bit = 0; bit < 8; bit++)
+        {
+            /* lorsque la valeur du MSB est 1, on execute le XOR en plus du decalage */
+            if ((current_byte & 0x80) != 0)
+            {
+                current_byte = current_byte << 1;
+                current_byte ^= CRC_GEN_NUM;
+            }
+            else
+            {
+                current_byte = current_byte << 1;
+            }
+        }
+        /* en ajoute cette valeur a la table des valeurs pre calculees */
+        crc_table[i] = current_byte;
+    }
+}
+
+char get_crc_value(char* buffer, int buffer_length)
+{
+    char crc = 0;
+    for (int i = 0; i < buffer_length; i++)
+    {
+        /* get current CRC value = remainder */
+        crc = crc_table[buffer[i] ^ crc];
+    }
+
+    return crc;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/crc.h	Sun Oct 22 20:20:42 2017 +0000
@@ -0,0 +1,8 @@
+
+
+
+#define CRC_GEN_NUM 0x1D
+
+void init_crc_module();
+
+char get_crc_value(char* buffer, int buffer_length);
\ No newline at end of file

--- a/main.cpp	Mon Oct 16 01:51:32 2017 +0000
+++ b/main.cpp	Sun Oct 22 20:20:42 2017 +0000
@@ -1,7 +1,6 @@
 #include "mbed.h"
 
 #include "radio.h"
-#include "quick_queue.h"
 
 // Debug serial output
 Serial debug_output(USBTX, USBRX);
@@ -30,12 +29,11 @@
 void display_all_messages(){
     radio_message_t* message;
 
-    while((message = get_last_in_message()) != NULL)
+    while(get_message(message))
     {
         // Display messages
         debug_output.printf("===========================\n\r");
         debug_output.printf("===========START===========\n\r");
-        debug_output.printf("OUT = %i :::: IN = %i\n\r", get_input_out_index(), get_input_in_index());
         debug_output.printf("Start value = 0x%x\n\r", message->start);
         debug_output.printf("Options value = 0x%x\n\r", message->options);
         debug_output.printf("Length value = %u\n\r", message->length);
@@ -46,8 +44,6 @@
         debug_output.printf("End value = 0x%x\n\r", message->end);
         debug_output.printf("===========================\n\r");
         //format
-
-        last_in_message_read();
         message = NULL;
     }
 }
\ No newline at end of file

--- a/radio.cpp	Mon Oct 16 01:51:32 2017 +0000
+++ b/radio.cpp	Sun Oct 22 20:20:42 2017 +0000
@@ -8,7 +8,7 @@
 #include "mbed.h"
 #include "rtos.h"
 
-
+#include "crc.h"
 // Vitesse de sortie des message manchester
 #define MANCHESTER_SPEED_OUT 4    
 
@@ -483,6 +483,7 @@
 */
 void init_radio_system()
 {
+   init_crc_module();
    setup_radio_in();   
    setup_radio_out(); 
 }
@@ -506,7 +507,7 @@
         }         
         
         // Ajouter calcul du CRC
-        message->control = 0xCE;
+        message->control = get_crc_value(message->data, message->length);//0xCE;
         
         message->end = FOOTER_END;
         // On avance dans le buffer;
@@ -516,6 +517,32 @@
     //////////////////////////////////////////////////////   
 }
 
+bool get_message(radio_message_t* message)
+{
+    radio_message_t* received_message;
+    // Si un message a ete recu par la radio
+    if((received_message = get_last_in_message()) != NULL)
+    {
+        // Si la valeur de CRC est valide par rapport a ce qui est calcule
+        if (get_crc_value(received_message->data, received_message->length) == received_message->control)
+        {
+            message->preambule = received_message->preambule;
+            message->start = received_message->start;
+            message->options = received_message->options;
+            message->length = received_message->length;
+            // memcopy
+            memcpy(message->data, received_message->data, received_message->length);
+            
+            message->control = received_message->control;
+            message->end = received_message->end;
+            
+            last_in_message_read();
+            return true;
+        }
+    }
+    return false;
+}
+
 ////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////

--- a/radio.h	Mon Oct 16 01:51:32 2017 +0000
+++ b/radio.h	Sun Oct 22 20:20:42 2017 +0000
@@ -16,7 +16,7 @@
     byte start;
     byte options;
     byte length;
-    byte data[MAX_MESSAGE_LENGTH] = { 0 };
+    byte data[MAX_MESSAGE_LENGTH];
     byte control;
     byte end;
 } radio_message_t;
@@ -25,4 +25,6 @@
 // public functions
 void init_radio_system();
 
-bool send_message(char* buffer, int length);
\ No newline at end of file
+bool send_message(char* buffer, int length);
+
+bool get_message(radio_message_t* message);
\ No newline at end of file