added idea for command parser

ideas/cmd_parser.cpp

@@ -0,0 +1,100 @@
+// Example program
+#include <iostream>
+#include <string>
+#include <array>
+#include <stdint.h>
+#include <iomanip>
+
+#define PACKET_N_BYTES 16
+
+using ui8_t = uint8_t;
+
+using packet_t = std::array<ui8_t, PACKET_N_BYTES>;
+using payload_t = std::array<ui8_t, 12>;
+
+const std::array<ui8_t,2> head = {0xAE, 0xAE};
+const std::array<ui8_t,2> tail = {0xAE, 0xAE};
+
+enum packetParts
+{
+    Head,
+    Payload,
+    Tail
+};
+
+void outputPayload(payload_t payload)
+{
+    
+    for (int i = 0; i < 12; ++i)
+        std::cout << std::hex << std::setfill('0') << std::setw(2) << payload[i] << " ";
+    std::cout << std::endl;
+}
+
+void parsePacket(const packet_t& newPacket)
+{
+    bool done = false;
+    payload_t payload;
+    packetParts packetIndex = Head;
+    ui8_t i = 0;
+
+    do {
+        switch(packetIndex) {
+            case Head:
+                std::cout << "checking packet head..." << std::endl;
+                // check head
+                for(i = 0; i < 2; i++) {
+                    if(head[i] != newPacket[i]) {
+                        std::cout << "...failed!" << std::endl;   
+                        return;
+                    }
+                }
+                std::cout << "...head valid!" << std::endl;
+                packetIndex = Payload;
+                break;
+            case Payload:
+                // copy payload
+                std::cout << "copy payload..." << std::endl;
+                for(;i < 14; i++) {
+                    payload[i - 2] = newPacket[i];
+                }
+                std::cout << "...done!" << std::endl;
+                packetIndex = Tail;
+                break;
+            case Tail:
+                // check tail
+                std::cout << "checking packet tail..." << std::endl;
+                for(;i < 16; i++) {
+                    if(tail[(i - 14)] != newPacket[i]) {
+                        std::cout << "...failed!" << std::endl;   
+                        return;
+                    }
+                }
+                std::cout << "...tail valid!" << std::endl;
+                std::cout << "forwarding payload!" << std::endl;
+                outputPayload(payload);
+                done = true;
+                break;
+            default:
+                return;
+        };
+    } while(!done);
+}
+
+
+
+
+int main()
+{
+    packet_t receivedPacket = {0xAE, 0xAE, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0xAE, 0xAE};
+                               
+    packet_t corruptedPacket = {0xAE, 0xAE, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0x00, 0x00,
+                               0x00, 0x00, 0xAE, 0xFE};         
+             
+    parsePacket(receivedPacket);
+    parsePacket(corruptedPacket);
+}