From 9866ff89591a0b9c93688964f8994b28473ce6be Mon Sep 17 00:00:00 2001
From: Lorenz Meier <lm@inf.ethz.ch>
Date: Sat, 20 Aug 2016 18:10:01 +0200
Subject: [PATCH] Allow sending a param with a different component ID

---
 src/modules/mavlink/mavlink_parameters.cpp | 14 ++++++++++++--
 src/modules/mavlink/mavlink_parameters.h   |  2 +-
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/modules/mavlink/mavlink_parameters.cpp b/src/modules/mavlink/mavlink_parameters.cpp
index 0393e0b453..dfdc8bb8bd 100644
--- a/src/modules/mavlink/mavlink_parameters.cpp
+++ b/src/modules/mavlink/mavlink_parameters.cpp
@@ -407,7 +407,7 @@ MavlinkParametersManager::send(const hrt_abstime t)
 }
 
 int
-MavlinkParametersManager::send_param(param_t param)
+MavlinkParametersManager::send_param(param_t param, int component_id)
 {
 	if (param == PARAM_INVALID) {
 		return 1;
@@ -446,7 +446,17 @@ MavlinkParametersManager::send_param(param_t param)
 		msg.param_type = MAVLINK_TYPE_FLOAT;
 	}
 
-	mavlink_msg_param_value_send_struct(_mavlink->get_channel(), &msg);
+	/* default component ID */
+	if (component_id < 0) {
+		mavlink_msg_param_value_send_struct(_mavlink->get_channel(), &msg);
+
+	} else {
+
+		// Re-pack the message with a different component ID
+		mavlink_message_t mavlink_packet;
+		mavlink_msg_param_value_encode_chan(mavlink_system.sysid, component_id, _mavlink->get_channel(), &mavlink_packet, &msg);
+		_mavlink_resend_uart(_mavlink->get_channel(), &mavlink_packet);
+	}
 
 	return 0;
 }
diff --git a/src/modules/mavlink/mavlink_parameters.h b/src/modules/mavlink/mavlink_parameters.h
index c2820a3e09..ce1d56363f 100644
--- a/src/modules/mavlink/mavlink_parameters.h
+++ b/src/modules/mavlink/mavlink_parameters.h
@@ -90,7 +90,7 @@ protected:
 
 	void send(const hrt_abstime t);
 
-	int send_param(param_t param);
+	int send_param(param_t param, int component_id=-1);
 
 	orb_advert_t _rc_param_map_pub;
 	struct rc_parameter_map_s _rc_param_map;