Make slaves send their protocol version to the master.

left/src/module.h

@@ -3,6 +3,7 @@
 
 // Macros:
 
+    #define MODULE_PROTOCOL_VERSION 1
     #define MODULE_KEY_COUNT (KEYBOARD_MATRIX_ROWS_NUM * KEYBOARD_MATRIX_COLS_NUM)
     #define MODULE_HAS_POINTER false
 

left/src/slave_protocol_handler.c

@@ -75,6 +75,11 @@ void SlaveTxHandler(void)
                     TxMessage.length = 1;
                     break;
                 }
+                case SlaveProperty_ProtocolVersion: {
+                    TxMessage.data[0] = MODULE_PROTOCOL_VERSION;
+                    TxMessage.length = 1;
+                    break;
+                }
                 case SlaveProperty_Features: {
                     uhk_module_features_t *moduleFeatures = (uhk_module_features_t*)&TxMessage.data;
                     moduleFeatures->keyCount = MODULE_KEY_COUNT;

right/src/slave_drivers/uhk_module_driver.c

@@ -87,11 +87,31 @@ status_t UhkModuleSlaveDriver_Update(uint8_t uhkModuleDriverId)
             bool isSyncValid = memcmp(rxMessage->data, SlaveSyncString, SLAVE_SYNC_STRING_LENGTH) == 0;
             status = kStatus_Uhk_NoTransfer;
             *uhkModulePhase = isSyncValid && isMessageValid
-                ? UhkModulePhase_RequestModuleId
+                ? UhkModulePhase_RequestProtocolVersion
                 : UhkModulePhase_RequestSync;
             break;
         }
 
+        // Get protocol version
+        case UhkModulePhase_RequestProtocolVersion:
+            txMessage.data[0] = SlaveCommand_RequestProperty;
+            txMessage.data[1] = SlaveProperty_ProtocolVersion;
+            txMessage.length = 2;
+            status = tx(i2cAddress);
+            *uhkModulePhase = UhkModulePhase_ReceiveProtocolVersion;
+            break;
+        case UhkModulePhase_ReceiveProtocolVersion:
+            status = rx(rxMessage, i2cAddress);
+            *uhkModulePhase = UhkModulePhase_ProcessProtocolVersion;
+            break;
+        case UhkModulePhase_ProcessProtocolVersion:
+            if (CRC16_IsMessageValid(rxMessage)) {
+                uhkModuleState->protocolVersion = rxMessage->data[0];
+            }
+            status = kStatus_Uhk_NoTransfer;
+            *uhkModulePhase = UhkModulePhase_RequestModuleId;
+            break;
+
         // Get module id
         case UhkModulePhase_RequestModuleId:
             txMessage.data[0] = SlaveCommand_RequestProperty;

right/src/slave_drivers/uhk_module_driver.h

@@ -26,6 +26,11 @@
         UhkModulePhase_ReceiveSync,
         UhkModulePhase_ProcessSync,
 
+        // Get protocol version
+        UhkModulePhase_RequestProtocolVersion,
+        UhkModulePhase_ReceiveProtocolVersion,
+        UhkModulePhase_ProcessProtocolVersion,
+
         // Get module id
         UhkModulePhase_RequestModuleId,
         UhkModulePhase_ReceiveModuleId,
@@ -54,6 +59,7 @@
 
     typedef struct {
         uint8_t moduleId;
+        uint8_t protocolVersion;
         uhk_module_phase_t phase;
         uhk_module_vars_t targetVars;
         i2c_message_t rxMessage;

shared/slave_protocol.h

@@ -27,6 +27,7 @@
 
     typedef enum {
         SlaveProperty_Sync,
+        SlaveProperty_ProtocolVersion,
         SlaveProperty_ModuleId,
         SlaveProperty_Features,
     } slave_property_t;