From b94eb542a9c4cc578265442f05f2457c7ee44c6b Mon Sep 17 00:00:00 2001
From: "Mikael Falkvidd git@mjo.se" <git@mjo.se>
Date: Thu, 30 May 2019 13:15:33 +0200
Subject: [PATCH] Rename "soft ack" to echo

The ack parameter is often confused with what might be called
"hardware ack"
(see https://forum.mysensors.org/post/34263 for one of many
lengthy discussions)

This change should make it harder to confuse echo with the
hardware ack, and reflects more accurately what will actually
happen.

This fixes https://github.com/mysensors/MySensors/issues/1103

I hope I have found all places where the naming needs to be
changed, and that I haven't inadvertently renamed any of the
*real* ack stuff.
---
 core/MyGatewayTransport.cpp |  11 ++--
 core/MyMessage.cpp          |   8 ++-
 core/MyMessage.h            |  31 ++++++----
 core/MyOTALogging.cpp       |   2 +-
 core/MyProtocol.cpp         |  16 ++---
 core/MySensorsCore.cpp      |  41 ++++++-------
 core/MySensorsCore.h        | 114 ++++++++++++++++++++++--------------
 core/MySigning.cpp          |   4 +-
 core/MySigning.h            |   2 +-
 core/MyTransport.cpp        |  20 +++----
 core/MyTransport.h          |   4 +-
 11 files changed, 146 insertions(+), 107 deletions(-)

diff --git a/core/MyGatewayTransport.cpp b/core/MyGatewayTransport.cpp
index 042631f6e..bab8bd1ae 100644
--- a/core/MyGatewayTransport.cpp
+++ b/core/MyGatewayTransport.cpp
@@ -31,13 +31,14 @@ inline void gatewayTransportProcess(void)
 		_msg = gatewayTransportReceive();
 		if (_msg.destination == GATEWAY_ADDRESS) {
 
-			// Check if sender requests an ack back.
-			if (mGetRequestAck(_msg)) {
+			// Check if sender requests an echo
+			if (mGetRequestEcho(_msg)) {
 				// Copy message
 				_msgTmp = _msg;
-				mSetRequestAck(_msgTmp,
-				               false); // Reply without ack flag (otherwise we would end up in an eternal loop)
-				mSetAck(_msgTmp, true);
+				// Reply without echo flag, otherwise we would end up in an eternal loop
+				mSetRequestEcho(_msgTmp,
+				                false);
+				mSetEcho(_msgTmp, true);
 				_msgTmp.sender = getNodeId();
 				_msgTmp.destination = _msg.sender;
 				gatewayTransportSend(_msgTmp);
diff --git a/core/MyMessage.cpp b/core/MyMessage.cpp
index 53514098c..305c9e78c 100644
--- a/core/MyMessage.cpp
+++ b/core/MyMessage.cpp
@@ -51,9 +51,15 @@ void MyMessage::clear(void)
 	miSetVersion(PROTOCOL_VERSION);
 }
 
+// TODO: Remove before v3 is released, use isEcho instead
 bool MyMessage::isAck(void) const
 {
-	return miGetAck();
+	return isEcho();
+}
+
+bool MyMessage::isEcho(void) const
+{
+	return miGetEcho();
 }
 
 uint8_t MyMessage::getCommand(void) const
diff --git a/core/MyMessage.h b/core/MyMessage.h
index 7a3f1dfe7..035cf307e 100644
--- a/core/MyMessage.h
+++ b/core/MyMessage.h
@@ -250,11 +250,11 @@ typedef enum {
 #define mSetCommand(_message,_command) BF_SET(_message.command_ack_payload, _command, 0, 3) //!< Set command field
 #define mGetCommand(_message) ((uint8_t)BF_GET(_message.command_ack_payload, 0, 3)) //!< Get command field
 
-#define mSetRequestAck(_message,_rack) BF_SET(_message.command_ack_payload, _rack, 3, 1) //!< Set ack-request field
-#define mGetRequestAck(_message) ((bool)BF_GET(_message.command_ack_payload, 3, 1)) //!< Get  ack-request field
+#define mSetRequestEcho(_message,_rack) BF_SET(_message.command_ack_payload, _rack, 3, 1) //!< Set ack-request field
+#define mGetRequestEcho(_message) ((bool)BF_GET(_message.command_ack_payload, 3, 1)) //!< Get  ack-request field
 
-#define mSetAck(_message,_ackMsg) BF_SET(_message.command_ack_payload, _ackMsg, 4, 1) //!< Set ack field
-#define mGetAck(_message) ((bool)BF_GET(_message.command_ack_payload, 4, 1)) //!< Get ack field
+#define mSetEcho(_message,_ackMsg) BF_SET(_message.command_ack_payload, _ackMsg, 4, 1) //!< Set ack field
+#define mGetEcho(_message) ((bool)BF_GET(_message.command_ack_payload, 4, 1)) //!< Get ack field
 
 #define mSetPayloadType(_message, _pt) BF_SET(_message.command_ack_payload, _pt, 5, 3) //!< Set payload type field
 #define mGetPayloadType(_message) ((uint8_t)BF_GET(_message.command_ack_payload, 5, 3)) //!< Get payload type field
@@ -269,11 +269,11 @@ typedef enum {
 #define miSetVersion(_version) BF_SET(version_length, _version, 0, 2) //!< Internal setter for version field
 #define miGetVersion() ((uint8_t)BF_GET(version_length, 0, 2)) //!< Internal getter for version field
 
-#define miSetRequestAck(_rack) BF_SET(command_ack_payload, _rack, 3, 1) //!< Internal setter for ack-request field
-#define miGetRequestAck() ((bool)BF_GET(command_ack_payload, 3, 1)) //!< Internal getter for ack-request field
+#define miSetRequestEcho(_rack) BF_SET(command_ack_payload, _rack, 3, 1) //!< Internal setter for echo request field
+#define miGetRequestEcho() ((bool)BF_GET(command_ack_payload, 3, 1)) //!< Internal getter for echo request field
 
-#define miSetAck(_ack) BF_SET(command_ack_payload, _ack, 4, 1) //!< Internal setter for ack field
-#define miGetAck() ((bool)BF_GET(command_ack_payload, 4, 1)) //!< Internal getter for ack field
+#define miSetEcho(_ack) BF_SET(command_ack_payload, _ack, 4, 1) //!< Internal setter for echo field
+#define miGetEcho() ((bool)BF_GET(command_ack_payload, 4, 1)) //!< Internal getter for echo field
 
 #define miSetPayloadType(_pt) BF_SET(command_ack_payload, _pt, 5, 3) //!< Internal setter for payload type field
 #define miGetPayloadType() (uint8_t)BF_GET(command_ack_payload, 5, 3) //!< Internal getter for payload type field
@@ -380,11 +380,18 @@ class MyMessage
 	uint8_t getCommand(void) const;
 
 	/**
-	 * @brief Getter for ack-flag.
-	 * @return true if this is an ack message
+	 * \deprecated, see isEcho
+	 * @brief Getter for echo-flag.
+	 * @return true if this is an echoed message
 	 */
 	bool isAck(void) const;
 
+	/**
+	 * @brief Getter for echo-flag.
+	 * @return true if this is an echoed message
+	 */
+	bool isEcho(void) const;
+
 	/**
 	 * @brief Set message type
 	 * @param type see http://korturl.nu/stupidurl
@@ -485,8 +492,8 @@ typedef union {
 
 	/**
 	 * 3 bit - Command type<br>
-	 * 1 bit - Request an ack - Indicator that receiver should send an ack back<br>
-	 * 1 bit - Is ack message - Indicator that this is the actual ack message<br>
+	 * 1 bit - Request an echo - Indicator that receiver should echo the message back to the sender<br>
+	 * 1 bit - Is echo message - Indicator that this is the echoed message<br>
 	 * 3 bit - Payload data type
 	 */
 	uint8_t command_ack_payload;
diff --git a/core/MyOTALogging.cpp b/core/MyOTALogging.cpp
index 5c3797fab..2e434ca5b 100644
--- a/core/MyOTALogging.cpp
+++ b/core/MyOTALogging.cpp
@@ -62,7 +62,7 @@ void OTALog(uint8_t logNode, bool enableAck, const char *fmt, ... )
 	msg.sender = getNodeId();
 	msg.setDestination(logNode);
 	mSetCommand(msg, C_INTERNAL);
-	mSetRequestAck(msg, enableAck);
+	mSetRequestEcho(msg, enableAck);
 
 	// Send package
 	for (int pos = 0; pos<n; pos+=MAX_PAYLOAD) {
diff --git a/core/MyProtocol.cpp b/core/MyProtocol.cpp
index 5d716f928..496ee1ee6 100644
--- a/core/MyProtocol.cpp
+++ b/core/MyProtocol.cpp
@@ -33,7 +33,7 @@ bool protocolSerial2MyMessage(MyMessage &message, char *inputString)
 	uint8_t command = 0;
 	message.sender = GATEWAY_ADDRESS;
 	message.last = GATEWAY_ADDRESS;
-	mSetAck(message, false);
+	mSetEcho(message, false);
 
 	// Extract command data coming on serial line
 	for (str = strtok_r(inputString, ";", &p); // split using semicolon
@@ -51,8 +51,8 @@ bool protocolSerial2MyMessage(MyMessage &message, char *inputString)
 			command = atoi(str);
 			mSetCommand(message, command);
 			break;
-		case 3: // Should we request ack from destination?
-			mSetRequestAck(message, atoi(str) ? 1 : 0);
+		case 3: // Should we request echo from destination?
+			mSetRequestEcho(message, atoi(str) ? 1 : 0);
 			break;
 		case 4: // Data type
 			message.type = atoi(str);
@@ -91,7 +91,7 @@ char *protocolMyMessage2Serial(MyMessage &message)
 {
 	(void)snprintf_P(_fmtBuffer, MY_GATEWAY_MAX_SEND_LENGTH,
 	                 PSTR("%" PRIu8 ";%" PRIu8 ";%" PRIu8 ";%" PRIu8 ";%" PRIu8 ";%s\n"), message.sender,
-	                 message.sensor, mGetCommand(message), mGetAck(message), message.type,
+	                 message.sensor, mGetCommand(message), mGetEcho(message), message.type,
 	                 message.getString(_convBuffer));
 	return _fmtBuffer;
 }
@@ -100,7 +100,7 @@ char *protocolMyMessage2MQTT(const char *prefix, MyMessage &message)
 {
 	(void)snprintf_P(_fmtBuffer, MY_GATEWAY_MAX_SEND_LENGTH,
 	                 PSTR("%s/%" PRIu8 "/%" PRIu8 "/%" PRIu8 "/%" PRIu8 "/%" PRIu8 ""), prefix,
-	                 message.sender, message.sensor, mGetCommand(message), mGetAck(message), message.type);
+	                 message.sender, message.sensor, mGetCommand(message), mGetEcho(message), message.type);
 	return _fmtBuffer;
 }
 
@@ -111,7 +111,7 @@ bool protocolMQTT2MyMessage(MyMessage &message, char *topic, uint8_t *payload,
 	uint8_t index = 0;
 	message.sender = GATEWAY_ADDRESS;
 	message.last = GATEWAY_ADDRESS;
-	mSetAck(message, false);
+	mSetEcho(message, false);
 	for (str = strtok_r(topic + strlen(MY_MQTT_SUBSCRIBE_TOPIC_PREFIX) + 1, "/", &p);
 	        str && index < 5;
 	        str = strtok_r(NULL, "/", &p)
@@ -150,8 +150,8 @@ bool protocolMQTT2MyMessage(MyMessage &message, char *topic, uint8_t *payload,
 			break;
 		}
 		case 3:
-			// Ack flag
-			mSetRequestAck(message, atoi(str) ? 1 : 0);
+			// Echo flag
+			mSetRequestEcho(message, atoi(str) ? 1 : 0);
 			break;
 		case 4:
 			// Sub type
diff --git a/core/MySensorsCore.cpp b/core/MySensorsCore.cpp
index 676a4b68d..854cf8bc8 100644
--- a/core/MySensorsCore.cpp
+++ b/core/MySensorsCore.cpp
@@ -320,11 +320,11 @@ bool _sendRoute(MyMessage &message)
 #endif
 }
 
-bool send(MyMessage &message, const bool enableAck)
+bool send(MyMessage &message, const bool echo)
 {
 	message.sender = getNodeId();
 	mSetCommand(message, C_SET);
-	mSetRequestAck(message, enableAck);
+	mSetRequestEcho(message, echo);
 
 #if defined(MY_REGISTRATION_FEATURE) && !defined(MY_GATEWAY_FEATURE)
 	if (_coreConfig.nodeRegistered) {
@@ -338,24 +338,24 @@ bool send(MyMessage &message, const bool enableAck)
 #endif
 }
 
-bool sendBatteryLevel(const uint8_t value, const bool ack)
+bool sendBatteryLevel(const uint8_t value, const bool echo)
 {
 	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_BATTERY_LEVEL,
-	                        ack).set(value));
+	                        echo).set(value));
 }
 
-bool sendHeartbeat(const bool ack)
+bool sendHeartbeat(const bool echo)
 {
 #if defined(MY_SENSOR_NETWORK)
 	const uint32_t heartbeat = transportGetHeartbeat();
 	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_HEARTBEAT_RESPONSE,
-	                        ack).set(heartbeat));
+	                        echo).set(heartbeat));
 #elif defined(MY_GATEWAY_FEATURE)
 	const uint32_t heartbeat = hwMillis();
 	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_HEARTBEAT_RESPONSE,
-	                        ack).set(heartbeat));
+	                        echo).set(heartbeat));
 #else
-	(void)ack;
+	(void)echo;
 	return false;
 #endif
 }
@@ -363,49 +363,49 @@ bool sendHeartbeat(const bool ack)
 
 
 bool present(const uint8_t childSensorId, const uint8_t sensorType, const char *description,
-             const bool ack)
+             const bool echo)
 {
 	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, childSensorId, C_PRESENTATION, sensorType,
-	                        ack).set(childSensorId == NODE_SENSOR_ID ? MYSENSORS_LIBRARY_VERSION : description));
+	                        echo).set(childSensorId == NODE_SENSOR_ID ? MYSENSORS_LIBRARY_VERSION : description));
 }
 
 #if !defined(__linux__)
 bool present(const uint8_t childSensorId, const uint8_t sensorType,
              const __FlashStringHelper *description,
-             const bool ack)
+             const bool echo)
 {
 	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, childSensorId, C_PRESENTATION, sensorType,
-	                        ack).set(childSensorId == NODE_SENSOR_ID ? F(" MYSENSORS_LIBRARY_VERSION "): description));
+	                        echo).set(childSensorId == NODE_SENSOR_ID ? F(" MYSENSORS_LIBRARY_VERSION "): description));
 }
 #endif
 
 
-bool sendSketchInfo(const char *name, const char *version, const bool ack)
+bool sendSketchInfo(const char *name, const char *version, const bool echo)
 {
 	bool result = true;
 	if (name) {
 		result &= _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_NAME,
-		                           ack).set(name));
+		                           echo).set(name));
 	}
 	if (version) {
 		result &= _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_VERSION,
-		                           ack).set(version));
+		                           echo).set(version));
 	}
 	return result;
 }
 
 #if !defined(__linux__)
 bool sendSketchInfo(const __FlashStringHelper *name, const __FlashStringHelper *version,
-                    const bool ack)
+                    const bool echo)
 {
 	bool result = true;
 	if (name) {
 		result &= _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_NAME,
-		                           ack).set(name));
+		                           echo).set(name));
 	}
 	if (version) {
 		result &= _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_VERSION,
-		                           ack).set(version));
+		                           echo).set(version));
 	}
 	return result;
 }
@@ -416,9 +416,10 @@ bool request(const uint8_t childSensorId, const uint8_t variableType, const uint
 	return _sendRoute(build(_msgTmp, destination, childSensorId, C_REQ, variableType).set(""));
 }
 
-bool requestTime(const bool ack)
+bool requestTime(const bool echo)
 {
-	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_TIME, ack).set(""));
+	return _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_TIME,
+	                        echo).set(""));
 }
 
 // Message delivered through _msg
diff --git a/core/MySensorsCore.h b/core/MySensorsCore.h
index ddd982a8e..d539c9a4a 100644
--- a/core/MySensorsCore.h
+++ b/core/MySensorsCore.h
@@ -125,75 +125,96 @@ uint8_t getParentNodeId(void);
 void presentNode(void);
 
 /**
-* Each node must present all attached sensors before any values can be handled correctly by the controller.
-* It is usually good to present all attached sensors after power-up in setup().
-*
-* @param sensorId Select a unique sensor id for this sensor. Choose a number between 0-254.
-* @param sensorType The sensor type. See sensor typedef in MyMessage.h.
-* @param description A textual description of the sensor.
-* @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
-* @param description A textual description of the sensor.
-* @return true Returns true if message reached the first stop on its way to destination.
-*/
+ * Each node must present all attached sensors before any values can be handled correctly by the controller.
+ * It is usually good to present all attached sensors after power-up in setup().
+ *
+ * @param sensorId Select a unique sensor id for this sensor. Choose a number between 0-254.
+ * @param sensorType The sensor type. See sensor typedef in MyMessage.h.
+ * @param description A textual description of the sensor.
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
+ * @param description A textual description of the sensor.
+ * @return true Returns true if message reached the first stop on its way to destination.
+ */
 bool present(const uint8_t sensorId, const uint8_t sensorType, const char *description = "",
-             const bool ack = false);
+             const bool echo = false);
 #if !defined(__linux__)
 bool present(const uint8_t childSensorId, const uint8_t sensorType,
              const __FlashStringHelper *description,
-             const bool ack = false);
+             const bool echo = false);
 #endif
 /**
  * Sends sketch meta information to the gateway. Not mandatory but a nice thing to do.
  * @param name String containing a short Sketch name or NULL if not applicable
  * @param version String containing a short Sketch version or NULL if not applicable
- * @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
  * @return true Returns true if message reached the first stop on its way to destination.
  */
-bool sendSketchInfo(const char *name, const char *version, const bool ack = false);
+bool sendSketchInfo(const char *name, const char *version, const bool echo = false);
 #if !defined(__linux__)
 bool sendSketchInfo(const __FlashStringHelper *name, const __FlashStringHelper *version,
-                    const bool ack = false);
+                    const bool echo = false);
 #endif
 
 /**
-* Sends a message to gateway or one of the other nodes in the radio network
-* @param msg Message to send
-* @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
-* @return true Returns true if message reached the first stop on its way to destination.
-*/
-bool send(MyMessage &msg, const bool ack = false);
+ * Sends a message to gateway or one of the other nodes in the radio network
+ * @param msg Message to send
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
+ * @return true Returns true if message reached the first stop on its way to destination.
+ */
+bool send(MyMessage &msg, const bool echo = false);
 
 /**
  * Send this nodes battery level to gateway.
  * @param level Level between 0-100(%)
- * @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
  * @return true Returns true if message reached the first stop on its way to destination.
  */
-bool sendBatteryLevel(const uint8_t level, const bool ack = false);
+bool sendBatteryLevel(const uint8_t level, const bool echo = false);
 
 /**
  * Send a heartbeat message (I'm alive!) to the gateway/controller.
  * The payload will be an incremental 16 bit integer value starting at 1 when sensor is powered on.
- * @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
  * @return true Returns true if message reached the first stop on its way to destination.
  */
-bool sendHeartbeat(const bool ack = false);
+bool sendHeartbeat(const bool echo = false);
 
 /**
-* Send this nodes signal strength to gateway.
-* @param level Signal strength can be RSSI if the radio provide it, or another kind of calculation
-* @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
-* @return true Returns true if message reached the first stop on its way to destination.
-*/
-bool sendSignalStrength(const int16_t level, const bool ack = false);
+ * Send this nodes signal strength to gateway.
+ * @param level Signal strength can be RSSI if the radio provide it, or another kind of calculation
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
+ * @return true Returns true if message reached the first stop on its way to destination.
+ */
+bool sendSignalStrength(const int16_t level, const bool echo = false);
 
 /**
-* Send this nodes TX power level to gateway.
-* @param level For instance, can be TX power level in dbm
-* @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
-* @return true Returns true if message reached the first stop on its way to destination.
-*/
-bool sendTXPowerLevel(const uint8_t level, const bool ack = false);
+ * Send this nodes TX power level to gateway.
+ * @param level For instance, can be TX power level in dbm
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
+ * @return true Returns true if message reached the first stop on its way to destination.
+ */
+bool sendTXPowerLevel(const uint8_t level, const bool echo = false);
 
 /**
 * Requests a value from gateway or some other sensor in the radio network.
@@ -209,10 +230,13 @@ bool request(const uint8_t childSensorId, const uint8_t variableType,
 
 /**
  * Requests time from controller. Answer will be delivered to receiveTime function in sketch.
- * @param ack Set this to true if you want destination node to send ack back to this node. Default is not to request any ack.
+ * @param echo Set this to true if you want destination node to echo the message back to this node.
+ * Default is not to request echo. If set to true, the final destination will echo back the
+ * contents of the message, triggering the receive() function on the original node with a copy of
+ * the message, with message.isEcho() set to true and sender/destination switched.
  * @return true Returns true if message reached the first stop on its way to destination.
  */
-bool requestTime(const bool ack = false);
+bool requestTime(const bool echo = false);
 
 /**
  * Returns the most recent node configuration received from controller
@@ -458,15 +482,15 @@ void loop(void) __attribute__((weak));
 
 // Inline function and macros
 static inline MyMessage& build(MyMessage &msg, const uint8_t destination, const uint8_t sensor,
-                               const uint8_t command, const uint8_t type, const bool ack = false)
+                               const uint8_t command, const uint8_t type, const bool echo = false)
 {
 	msg.sender = getNodeId();
 	msg.destination = destination;
 	msg.sensor = sensor;
 	msg.type = type;
-	mSetCommand(msg,command);
-	mSetRequestAck(msg,ack);
-	mSetAck(msg,false);
+	mSetCommand(msg, command);
+	mSetRequestEcho(msg, echo);
+	mSetEcho(msg, false);
 	return msg;
 }
 
@@ -477,8 +501,8 @@ static inline MyMessage& buildGw(MyMessage &msg, const uint8_t type)
 	msg.sensor = NODE_SENSOR_ID;
 	msg.type = type;
 	mSetCommand(msg, C_INTERNAL);
-	mSetRequestAck(msg, false);
-	mSetAck(msg, false);
+	mSetRequestEcho(msg, false);
+	mSetEcho(msg, false);
 	return msg;
 }
 
diff --git a/core/MySigning.cpp b/core/MySigning.cpp
index 7c2eb4c36..8eabfabc6 100644
--- a/core/MySigning.cpp
+++ b/core/MySigning.cpp
@@ -353,7 +353,7 @@ int signerMemcmp(const void* a, const void* b, size_t sz)
 static bool skipSign(MyMessage &msg)
 {
 	bool ret = false;
-	if (mGetAck(msg)) {
+	if (mGetEcho(msg)) {
 		ret = true;
 	}	else if (mGetCommand(msg) == C_INTERNAL &&
 	             (msg.type == I_SIGNING_PRESENTATION	||
@@ -373,7 +373,7 @@ static bool skipSign(MyMessage &msg)
 		ret = true;
 	}
 	if (ret) {
-		SIGN_DEBUG(PSTR("SGN:SKP:%s CMD=%" PRIu8 ",TYPE=%" PRIu8 "\n"), mGetAck(msg) ? "ACK" : "MSG",
+		SIGN_DEBUG(PSTR("SGN:SKP:%s CMD=%" PRIu8 ",TYPE=%" PRIu8 "\n"), mGetEcho(msg) ? "ACK" : "MSG",
 		           mGetCommand(msg),
 		           msg.type); //Skip signing/verification of this message
 	}
diff --git a/core/MySigning.h b/core/MySigning.h
index ecc9717c6..7706351ed 100644
--- a/core/MySigning.h
+++ b/core/MySigning.h
@@ -791,7 +791,7 @@ int signerMemcmp(const void* a, const void* b, size_t sz);
  * | | SGN | VER | LEFT='number'						| 'number' of failed verifications left in a row before node is locked
  * |!| SGN | VER | STATE  									| Security system in a invalid state (personalization data tampered)
  * | | SGN | SKP | MSG CMD='cmd',TYPE='type'| Message with command 'cmd' and type 'type' does not need to be signed
- * | | SGN | SKP | ACK CMD='cmd',TYPE='type'| ACK messages does not need to be signed
+ * | | SGN | SKP | ECHO CMD='cmd',TYPE='type'| ECHO messages does not need to be signed
  * | | SGN | NCE | LEFT='number'						| 'number' of nonce requests between successful verifications left before node is locked
  * | | SGN | NCE | XMT,TO='node'						| Nonce data transmitted to 'node'
  * |!| SGN | NCE | XMT,TO='node' FAIL				| Nonce data not properly transmitted to 'node'
diff --git a/core/MyTransport.cpp b/core/MyTransport.cpp
index 15a7903ce..61192f004 100644
--- a/core/MyTransport.cpp
+++ b/core/MyTransport.cpp
@@ -701,20 +701,20 @@ void transportProcessMessage(void)
 		mSetLength(_msg, min(mGetLength(_msg), (uint8_t)MAX_PAYLOAD));
 		// null terminate data
 		_msg.data[msgLength] = 0u;
-		// Check if sender requests an ack back.
-		if (mGetRequestAck(_msg)) {
-			TRANSPORT_DEBUG(PSTR("TSF:MSG:ACK REQ\n"));	// ACK requested
+		// Check if sender requests an echo.
+		if (mGetRequestEcho(_msg)) {
+			TRANSPORT_DEBUG(PSTR("TSF:MSG:ECHO REQ\n"));	// ECHO requested
 			_msgTmp = _msg;	// Copy message
-			// Reply without ack flag (otherwise we would end up in an eternal loop)
-			mSetRequestAck(_msgTmp, false);
-			mSetAck(_msgTmp, true); // set ACK flag
+			// Reply without echo flag (otherwise we would end up in an eternal loop)
+			mSetRequestEcho(_msgTmp, false);
+			mSetEcho(_msgTmp, true); // set ECHO flag
 			_msgTmp.sender = _transportConfig.nodeId;
 			_msgTmp.destination = sender;
-			// send ACK, use transportSendRoute since ACK reply is not internal, i.e. if !transportOK do not reply
+			// send ECHO, use transportSendRoute since ECHO reply is not internal, i.e. if !transportOK do not reply
 			(void)transportSendRoute(_msgTmp);
 		}
-		if(!mGetAck(_msg)) {
-			// only process if not ACK
+		if(!mGetEcho(_msg)) {
+			// only process if not ECHO
 			if (command == C_INTERNAL) {
 				// Process signing related internal messages
 				if (signerProcessInternal(_msg)) {
@@ -817,7 +817,7 @@ void transportProcessMessage(void)
 			}
 		} else {
 			TRANSPORT_DEBUG(
-			    PSTR("TSF:MSG:ACK\n")); // received message is ACK, no internal processing, handover to msg callback
+			    PSTR("TSF:MSG:ECHO\n")); // received message is ECHO, no internal processing, handover to msg callback
 		}
 #if defined(MY_OTA_LOG_RECEIVER_FEATURE)
 		if ((type == I_LOG_MESSAGE) && (command == C_INTERNAL)) {
diff --git a/core/MyTransport.h b/core/MyTransport.h
index 6d19fc9a4..cac88d2ae 100644
--- a/core/MyTransport.h
+++ b/core/MyTransport.h
@@ -91,8 +91,8 @@
 * |!| TSF | SID   | FAIL,ID=%%d								| Assigned ID is invalid
 * | | TSF | PNG   | SEND,TO=%%d								| Send ping to destination (TO)
 * | | TSF | WUR   | MS=%%lu										| Wait until transport ready, timeout (MS)
-* | | TSF | MSG   | ACK REQ										| ACK message requested
-* | | TSF | MSG   | ACK												| ACK message, do not proceed but forward to callback
+* | | TSF | MSG   | ECHO REQ										| ECHO message requested
+* | | TSF | MSG   | ECHO												| ECHO message, do not proceed but forward to callback
 * | | TSF | MSG   | FPAR RES,ID=%%d,D=%%d			| Response to find parent received from node (ID) with distance (D) to GW
 * | | TSF | MSG   | FPAR PREF FOUND						| Preferred parent found, i.e. parent defined via MY_PARENT_NODE_ID
 * | | TSF | MSG   | FPAR OK,ID=%%d,D=%%d			| Find parent response from node (ID) is valid, distance (D) to GW