Diff: main.cpp

Revision:

5:b73ea174e997

Parent:

4:f537311ddc53

Child:

6:ec3b01ce9687

--- a/main.cpp	Tue Oct 14 09:10:45 2014 +0000
+++ b/main.cpp	Tue Oct 14 14:54:32 2014 +0000
@@ -7,7 +7,7 @@
 
 const int SLAVE_ADDRESS = 0x84;
 const int I2C_FREQUENCY = 100000;
-const int I2C_BUFFER_SIZE = 5;
+const int I2C_BUFFER_SIZE = 6;
 
 enum COMMAND { PUSH, PULL, CLEAR, PRINT };
 
@@ -40,14 +40,14 @@
     int pointer = 0;
     
     while (1) {
-        int i = slave.receive();
-        switch (i) {
+        int rec = slave.receive();
+        switch (rec) {
             case I2CSlave::ReadAddressed:
             {
                 int value = memory.get(pointer);
                 buffer[0] = pointer;
                 intToByte(buffer+1, value);
-                if (!slave.write(buffer, I2C_BUFFER_SIZE)) {
+                if (!slave.write(buffer, 5)) {
                     pc.printf("Retrieving and sending to master %d@%d\r\n", value, pointer);
                 } else {
                     pc.printf("Failed to send to master %d@%d\r\n", value, pointer);
@@ -56,45 +56,52 @@
             }
             case I2CSlave::WriteAddressed:
             {
-                if (!slave.read(buffer, I2C_BUFFER_SIZE)) {
-                    // Check command byte
-                    switch (buffer[0]) {
-                        case PUSH:
-                        {
-                            int address = buffer[1];
+                // First we read the command byte
+                int command = slave.read();
+                
+                // Check the command
+                switch (command)
+                {
+                    case PUSH:
+                        // Expect 5 more bytes [address] [int value]
+                        if(!slave.read(buffer, 5)) {
+                            int address = buffer[0];
                             int value;
-                            byteToInt(buffer+2, &value);
+                            byteToInt(buffer+1, &value);
                             pc.printf("Storing %d@%d\r\n", value, address);
                             memory.set(address, value);
-                            break;
+                        } else {
+                            pc.printf("PUSH received with missing address/data\r\n");   
                         }
-                        
-                        case PRINT:
-                        {
-                            memory.print();
-                            break;
-                        }
-                            
-                        case PULL:
-                        {
-                            pc.printf("Setting pointer to %d\r\n", buffer[1]);
-                            if (buffer[1] < Memory::MEMORY_SIZE) {
-                                pointer = buffer[1];
+                        break;
+                    
+                    case PULL:
+                        // Expect 1 more byte [address]
+                        if(!slave.read(buffer, 1)) {
+                            int address = buffer[0];
+                            pc.printf("Setting pointer to %d\r\n", address);
+                            if (address < Memory::MEMORY_SIZE) {
+                                pointer = address;
                             } else {
                                 pc.printf("Address out of boundary\r\n");    
                             }
-                            break;
+                        } else {
+                            pc.printf("PULL received with missing address\r\n");   
                         }
-                        
-                        default:
-                        {
-                            pc.printf("Unknown command byte\r\n");
-                        }
-                    }
-                } else {
-                    pc.printf("Received WriteAddressed] without data\r\n");
+                        break;
+                    
+                    case CLEAR:
+                        pc.printf("Clearing the memory\r\n");    
+                        memory.reset();
+                        break;
+                    
+                    case PRINT:
+                        memory.print();
+                        break;
+                    
+                    default:
+                        pc.printf("Unknown command byte\r\n");
                 }
-                break;
             }
         }