diff --git a/protocol.c b/protocol.c
new file mode 100644
--- /dev/null
+++ b/protocol.c
@@ -0,0 +1,104 @@
+#include "protocol.h"
+
+
+bool protocol_receive_message(CanRxMsgTypeDef* can_message)
+{
+    bool result = true;
+    
+    protocol_message_t message;
+    message.command = can_message->Data[0] & 0x80;
+    message.id = can_message->Data[0] & 0x7F;
+    message.key = (can_message->Data[1] << 8) & can_message->Data[2];
+    message.sensor = can_message->Data[3];
+    message.data.byte_data[0] = can_message->Data[4];
+    message.data.byte_data[1] = can_message->Data[5];
+    message.data.byte_data[2] = can_message->Data[6];
+    message.data.byte_data[3] = can_message->Data[7];
+    
+    protocol_process_message(&message);
+    
+    return result;
+}
+
+bool protocol_send_message(protocol_message_t* message)
+{
+    bool result = true;
+    uint8_t data[8];
+    
+    data[0] = (message->command & 0x80) & (message->id & 0x7F);
+    data[1] = (message->key >> 8) & 0xFF;
+    data[2] = (message->key >> 0) & 0xFF;
+    data[3] = message->sensor;
+    data[4] = (message->data.byte_data[0] >> 24) & 0xFF;
+    data[5] = (message->data.byte_data[1] >> 16) & 0xFF;
+    data[6] = (message->data.byte_data[2] >> 8) & 0xFF;
+    data[7] = (message->data.byte_data[3] >> 0) & 0xFF;
+    
+    can_send(CAN_SEND_ID, CAN_ID_STD, 8, data);
+    
+    return result;
+}
+
+bool protocol_process_message(protocol_message_t* message)
+{
+    bool result = true;
+    
+    if (message->command)
+    {
+        switch(message->id)
+        {
+            case ESTOP:
+                {
+                    //call estop weak function
+                    result = protocol_estop(message->data.float_data!=0.0f);
+                }
+                break;
+            case SILENCE_BUS:
+                {
+                    //silence can bus
+                    result = can_silence_bus(message->data.float_data!=0.0f);
+                }
+                break;
+            case SET_OUTPUT:
+                {
+                    //call set output weak function
+                    result = protocol_set_output(message);
+                }
+                break;
+            case GET_DATA:
+                {
+                    //call get data weak function
+                    result = protocol_get_data(message);
+                }
+                break;
+            case CONFIG:
+                {
+                    //call config weak function
+                    result = protocol_config(message);
+                }
+                break;
+        }
+    }
+    
+    return result;
+}
+
+__weak bool protocol_estop(bool value)
+{
+    return false;
+}
+
+__weak bool protocol_set_output(protocol_message_t* message)
+{
+    return false;
+}
+
+__weak bool protocol_get_data(protocol_message_t* message)
+{
+    return false;
+}
+
+__weak bool protocol_config(protocol_message_t* message)
+{
+    return false;
+}
diff --git a/protocol.h b/protocol.h
new file mode 100644
--- /dev/null
+++ b/protocol.h
@@ -0,0 +1,61 @@
+#ifndef _PROTOCOL_H
+#define _PROTOCOL_H
+
+#include <stdbool.h>
+
+#include "config.h"
+#include "can.h"
+
+typedef struct {
+    bool command;
+    uint8_t id;
+    uint16_t key;
+    uint8_t sensor;
+    union {
+    	float float_data;
+		uint8_t byte_data[4];
+    } data;
+}  protocol_message_t;
+
+typedef enum {
+    ESTOP = 0x00,
+    SILENCE_BUS = 0x01,
+    SET_OUTPUT = 0X10,
+    GET_DATA = 0x11,
+    CONFIG = 0x12,
+    CALIBRATE = 0x13,
+} protocol_command_t;
+
+typedef enum {
+    NONE = 0x0000,
+    DIGITAL_INPUT = 0x0001,
+    FREQ_INPUT = 0x0002,
+    ANALOG_INPUT = 0x0003,
+    DIGITAL_OUTPUT = 0x0004,
+    FREQ_OUTPUT = 0x0005,
+    ANALOG_OUTPUT = 0x0006,
+    AIR_TEMP = 0x0007,
+    AIR_HUMIDITY = 0x0008,
+    AIR_PRESSURE = 0x0009,
+    AMBIENT_LIGHT = 0x000A,
+    WATER_TEMP = 0x000B,
+    WATER_LEVEL = 0x000C,
+    WATER_CONDUCTIVITY = 0x000D,
+    WATER_PH = 0x000E,
+    CAN_ID = 0x0100,
+    DATA_RATE = 0x0101,
+    GPIO = 0x0102,
+    LED_BRIGHTNESS = 0x0103,
+} protocol_data_key_t;
+
+
+bool protocol_receive_message(CanRxMsgTypeDef* can_message);
+bool protocol_send_message(protocol_message_t* message);
+bool protocol_process_message(protocol_message_t* message);
+
+__weak bool protocol_estop(bool value);
+__weak bool protocol_set_output(protocol_message_t* message);
+__weak bool protocol_get_data(protocol_message_t* message);
+__weak bool protocol_config(protocol_message_t* message);
+
+#endif //_PROTOCOL_H