diff --git a/debugging_tool/server.py b/debugging_tool/server.py
index 4a580bb..c8984e2 100644
--- a/debugging_tool/server.py
+++ b/debugging_tool/server.py
@@ -42,8 +42,9 @@ class Message:
     def sender_id(self):
         return (self.received_from >> 0) & 0b1111_1111
 
-    def human_readable_type(self):
-        return [('controller' if self.sender_id() == 0 else 'info'), 'puzzle', 'needy', 'RESERVED TYPE'][self.sender_type()]
+    @staticmethod
+    def human_readable_type(sender_type, sender_id):
+        return [('controller' if sender_id == 0 else 'info'), 'puzzle', 'needy', 'RESERVED TYPE'][sender_type]
 
     def _parse_state_update(self):
         timeleft = self.payload[1] << 0x18 | self.payload[2] << 0x10 | self.payload[3] << 0x08 | self.payload[4]
@@ -58,7 +59,7 @@ class Message:
         try:
             if sender_type == 0b00 and self.sender_id() == 0:  # controller
                 if message_type == 0:
-                    return "ACK"
+                    return f"ACK {Message.human_readable_type(self.payload[1], self.payload[2])} {self.payload[2]}"
                 elif message_type == 1:
                     return "HELLO"
                 elif message_type == 2:
@@ -99,7 +100,7 @@ class Message:
             'parsed': self.parse_message(),
             'pretty_raw_sender_id': f'{self.priority_bit():01b} {self.sender_type():02b} {self.sender_id():08b}',
             'raw_message': f"{self.payload.hex(' ')}",
-            'human_readable_type': self.human_readable_type(),
+            'human_readable_type': Message.human_readable_type(self.sender_type(), self.sender_id()),
             'sender_id': self.sender_id(),
             'internal_id': self.internal_id
         }
diff --git a/docs/protocol.txt b/docs/protocol.txt
index 3c2c543..0ef8eef 100644
--- a/docs/protocol.txt
+++ b/docs/protocol.txt
@@ -38,8 +38,10 @@ Types for controller:
 
     - 0 acknowledge valid message
       [ X B B B  B B B B ]
-          --------------
-             reserved
+          - - ----------
+          | ↓  reserved
+          ↓ module ID
+       type
 
     - 1 hello
       [ X B B B  B B B B ]
@@ -64,10 +66,10 @@ Types for controller:
           end time ↓ ↓ reserved
             #strikes #max strikes
 
-		- 7 info start
+    - 7 info start
       [ X B B B  B B B B ]
           --------------
-					   reserved
+             reserved
 
     - 8-255 reserved
 
diff --git a/lib/obus_can.cpp b/lib/obus_can.cpp
index 34d2178..421dd1a 100644
--- a/lib/obus_can.cpp
+++ b/lib/obus_can.cpp
@@ -37,6 +37,7 @@ uint8_t payload_type(uint8_t module_type, uint8_t module_id, uint8_t msg_type) {
 	if (module_type == OBUS_TYPE_CONTROLLER && module_id == OBUS_CONTROLLER_ID) {
 		switch (msg_type) {
 			case OBUS_MSGTYPE_C_ACK:
+			  return OBUS_PAYLDTYPE_MODULEADDR;
 			case OBUS_MSGTYPE_C_HELLO:
 				return OBUS_PAYLDTYPE_EMPTY;
 
@@ -137,6 +138,16 @@ bool receive(struct message *msg) {
 				msg->infomessage.len = data_len;
 			}
 			break;
+		case OBUS_PAYLDTYPE_MODULEADDR:
+			{
+				if (receive_frame.can_dlc < 3) {
+					Serial.println(F("W Received illegal count msg: payload <3"));
+					return false;
+				}
+				msg->payload_address.type = receive_frame.data[1];
+				msg->payload_address.id = receive_frame.data[2];
+			}
+			break;
 		default:
 			Serial.println(F("W Couldn't determine payload type"));
 			return false;
@@ -188,6 +199,11 @@ void send(struct message *msg) {
 			length = msg->infomessage.len + 1;
 			break;
 
+		case OBUS_PAYLDTYPE_MODULEADDR:
+			send_frame.data[1] = msg->payload_address.type;
+			send_frame.data[2] = msg->payload_address.id;
+		break;
+
 		default:
 			Serial.print(F("E Unknown payload type "));
 			Serial.println(pyld_type);
diff --git a/lib/obus_can.h b/lib/obus_can.h
index b384ea2..3a3a420 100644
--- a/lib/obus_can.h
+++ b/lib/obus_can.h
@@ -35,6 +35,7 @@
 #define OBUS_PAYLDTYPE_GAMESTATUS 1
 #define OBUS_PAYLDTYPE_COUNT      2
 #define OBUS_PAYLDTYPE_INFO       3
+#define OBUS_PAYLDTYPE_MODULEADDR 4
 
 #define OBUS_PAYLD_INFO_MAXLEN (OBUS_MSG_LENGTH - 1)
 
@@ -66,6 +67,7 @@ struct message {
 		struct payld_gamestatus gamestatus;
 		uint8_t count;
 		struct payld_infomessage infomessage;
+		struct module payload_address;
 	};
 };
 
@@ -140,9 +142,10 @@ inline void _send_payld_gamestatus(
 /**
  * Send a controller "ACK" OBUS message
  */
-inline void send_c_ack(struct module from) {
+inline void send_c_ack(struct module from, struct module payload_address) {
 	assert(from.type == OBUS_TYPE_CONTROLLER);
 	struct message msg = _msg(from, false, OBUS_MSGTYPE_C_ACK);
+	msg.payload_address = payload_address;
 	send(&msg);
 }
 
@@ -200,6 +203,15 @@ inline void send_c_timeout(
 			from, false, OBUS_MSGTYPE_C_TIMEOUT, time_left, strikes, max_strikes);
 }
 
+/**
+ * Send a controller "info start" OBUS message
+ */
+inline void send_c_infostart(struct module from) {
+	assert(from.type == OBUS_TYPE_CONTROLLER);
+	struct message msg = _msg(from, false, OBUS_MSGTYPE_C_INFOSTART);
+	send(&msg);
+}
+
 /**
  * Send a controller "strikeout" OBUS message
  */
diff --git a/src/controller/controller.ino b/src/controller/controller.ino
index 2d86a71..d439ec9 100644
--- a/src/controller/controller.ino
+++ b/src/controller/controller.ino
@@ -157,7 +157,7 @@ void receive_hello() {
 				Serial.println(F("W Max # modules reached"));
 			}
 
-			obus_can::send_c_ack(this_module);
+			obus_can::send_c_ack(this_module, msg.from);
 			Serial.println("  ACK");
 		}