added an rc switch for arming and disarming with the option to use it as a button

msg/manual_control_setpoint.msg

@@ -51,6 +51,7 @@ uint8 loiter_switch		 # loiter 2 position switch (optional): _MISSION_, LOITER
 uint8 acro_switch		 # acro 2 position switch (optional): _MANUAL_, ACRO
 uint8 offboard_switch	 # offboard 2 position switch (optional): _NORMAL_, OFFBOARD
 uint8 kill_switch		 # throttle kill: _NORMAL_, KILL
+uint8 arm_switch		 # arm/disarm switch: _DISARMED_, ARMED
 uint8 transition_switch	 # VTOL transition switch: _HOVER, FORWARD_FLIGHT
 uint8 gear_switch	 # landing gear switch: _DOWN_, UP
 int8 mode_slot			 # the slot a specific model selector is in

msg/rc_channels.msg

@@ -22,11 +22,12 @@ uint8 RC_CHANNELS_FUNCTION_RATTITUDE=19
 uint8 RC_CHANNELS_FUNCTION_KILLSWITCH=20
 uint8 RC_CHANNELS_FUNCTION_TRANSITION=21
 uint8 RC_CHANNELS_FUNCTION_GEAR=22
+uint8 RC_CHANNELS_FUNCTION_ARMSWITCH=23
 
 uint64 timestamp_last_valid					# Timestamp of last valid RC signal
 float32[18] channels						# Scaled to -1..1 (throttle: 0..1)
 uint8 channel_count						# Number of valid channels
-int8[23] function						# Functions mapping
+int8[24] function						# Functions mapping
 uint8 rssi							# Receive signal strength indicator (0-100)
 bool signal_lost						# Control signal lost, should be checked together with topic timeout
 uint32 frame_drop_count						# Number of dropped frames

src/modules/commander/commander.cpp

@@ -209,6 +209,7 @@ static uint8_t main_state_before_rtl = commander_state_s::MAIN_STATE_MAX;
 static unsigned _last_mission_instance = 0;
 struct manual_control_setpoint_s sp_man = {};		///< the current manual control setpoint
 static manual_control_setpoint_s _last_sp_man = {};	///< the manual control setpoint valid at the last mode switch
+static uint8_t _last_sp_man_arm_switch = 0;
 
 static struct vtol_vehicle_status_s vtol_status = {};
 static struct cpuload_s cpuload = {};
@@ -1297,6 +1298,7 @@ int commander_thread_main(int argc, char *argv[])
 	param_t _param_low_bat_act = param_find("COM_LOW_BAT_ACT");
 	param_t _param_offboard_loss_timeout = param_find("COM_OF_LOSS_T");
 	param_t _param_arm_without_gps = param_find("COM_ARM_WO_GPS");
+	param_t _param_arm_switch_is_button = param_find("COM_ARM_SWISBTN");
 
 	param_t _param_fmode_1 = param_find("COM_FLTMODE1");
 	param_t _param_fmode_2 = param_find("COM_FLTMODE2");
@@ -1642,6 +1644,8 @@ int commander_thread_main(int argc, char *argv[])
 	param_get(_param_autostart_id, &autostart_id);
 	param_get(_param_rc_in_off, &rc_in_off);
 	param_get(_param_arm_without_gps, &arm_without_gps);
+	int32_t arm_switch_is_button = 0;
+	param_get(_param_arm_switch_is_button, &arm_switch_is_button);
 	can_arm_without_gps = (arm_without_gps == 1);
 	status.rc_input_mode = rc_in_off;
 	if (is_hil_setup(autostart_id)) {
@@ -1782,6 +1786,7 @@ int commander_thread_main(int argc, char *argv[])
 			param_get(_param_offboard_loss_act, &offboard_loss_act);
 			param_get(_param_offboard_loss_rc_act, &offboard_loss_rc_act);
 			param_get(_param_arm_without_gps, &arm_without_gps);
+			param_get(_param_arm_switch_is_button, &arm_switch_is_button);
 			can_arm_without_gps = (arm_without_gps == 1);
 
 			/* Autostart id */
@@ -2555,7 +2560,7 @@ int commander_thread_main(int argc, char *argv[])
 
 			status.rc_signal_lost = false;
 
-			/* check if left stick is in lower left position and we are in MANUAL, Rattitude, or AUTO_READY mode or (ASSIST mode and landed) -> disarm
+			/* check if left stick is in lower left position or arm button is pushed and we are in MANUAL, Rattitude, or AUTO_READY mode or (ASSIST mode and landed) -> disarm
 			 * do it only for rotary wings in manual mode or fixed wing if landed */
 			if ((status.is_rotary_wing || (!status.is_rotary_wing && land_detector.landed)) && status.rc_input_mode != vehicle_status_s::RC_IN_MODE_OFF &&
 			    (status.arming_state == vehicle_status_s::ARMING_STATE_ARMED || status.arming_state == vehicle_status_s::ARMING_STATE_ARMED_ERROR) &&
@@ -2564,7 +2569,7 @@ int commander_thread_main(int argc, char *argv[])
 			    	internal_state.main_state == commander_state_s::MAIN_STATE_STAB ||
 			    	internal_state.main_state == commander_state_s::MAIN_STATE_RATTITUDE ||
 			    	land_detector.landed) &&
-			    sp_man.r < -STICK_ON_OFF_LIMIT && sp_man.z < 0.1f) {
+			    ((sp_man.r < -STICK_ON_OFF_LIMIT && sp_man.z < 0.1f) || ((bool)arm_switch_is_button && sp_man.arm_switch == manual_control_setpoint_s::SWITCH_POS_ON)) ) {
 
 				if (stick_off_counter > rc_arm_hyst) {
 					/* disarm to STANDBY if ARMED or to STANDBY_ERROR if ARMED_ERROR */
@@ -2596,8 +2601,10 @@ int commander_thread_main(int argc, char *argv[])
 				stick_off_counter = 0;
 			}
 
-			/* check if left stick is in lower right position and we're in MANUAL mode -> arm */
-			if (sp_man.r > STICK_ON_OFF_LIMIT && sp_man.z < 0.1f && status.rc_input_mode != vehicle_status_s::RC_IN_MODE_OFF ) {
+			/* check if left stick is in lower right position or arm button is pushed and we're in MANUAL mode -> arm */
+			if (status.rc_input_mode != vehicle_status_s::RC_IN_MODE_OFF &&
+					(status.arming_state != vehicle_status_s::ARMING_STATE_ARMED && status.arming_state != vehicle_status_s::ARMING_STATE_ARMED_ERROR) &&
+					((sp_man.r > STICK_ON_OFF_LIMIT && sp_man.z < 0.1f) || (arm_switch_is_button == 1 && sp_man.arm_switch == manual_control_setpoint_s::SWITCH_POS_ON)) ) {
 				if (stick_on_counter > rc_arm_hyst) {
 
 					/* we check outside of the transition function here because the requirement
@@ -2697,6 +2704,24 @@ int commander_thread_main(int argc, char *argv[])
 			}
 			/* no else case: do not change lockdown flag in unconfigured case */
 
+			/* check arm switch */
+			/* we change the switch from disarm to arm */
+			if (arm_switch_is_button == 0 && _last_sp_man_arm_switch == manual_control_setpoint_s::SWITCH_POS_OFF && sp_man.arm_switch == manual_control_setpoint_s::SWITCH_POS_ON) {
+				if (TRANSITION_CHANGED != arm_disarm(true, &mavlink_log_pub, "arm switch")) {
+					mavlink_log_info(&mavlink_log_pub, "arming failed");
+				} else {
+					arming_state_changed = true;
+				}
+			/* we change the switch from arm to disarm */
+			} else if (arm_switch_is_button == 0 && _last_sp_man_arm_switch == manual_control_setpoint_s::SWITCH_POS_ON && sp_man.arm_switch == manual_control_setpoint_s::SWITCH_POS_OFF) {
+				if (TRANSITION_CHANGED != arm_disarm(false, &mavlink_log_pub, "arm switch")) {
+					mavlink_log_info(&mavlink_log_pub, "rejected disarm");
+				} else {
+					arming_state_changed = true;
+				}
+			}
+			/* no else case: do not change arming here if arm switch unconfigured */
+			_last_sp_man_arm_switch = sp_man.arm_switch;
 		} else {
 			if (!status_flags.rc_input_blocked && !status.rc_signal_lost) {
 				mavlink_log_critical(&mavlink_log_pub, "MANUAL CONTROL LOST (at t=%llums)", hrt_absolute_time() / 1000);

src/modules/commander/commander_params.c

@@ -279,6 +279,20 @@ PARAM_DEFINE_INT32(COM_DISARM_LAND, 0);
  */
 PARAM_DEFINE_INT32(COM_ARM_WO_GPS, 1);
 
+/**
+ * Use arm switch is only a button
+ *
+ * The default uses the arm switch as real switch.
+ * If parameter set button gets handled like stick arming.
+ *
+ * @group Commander
+ * @min 0
+ * @max 1
+ * @value 0 Arm switch is a switch that stays on when armed
+ * @value 1 Arm switch is a button that only triggers arming
+ */
+PARAM_DEFINE_INT32(COM_ARM_SWISBTN, 0);
+
 /**
  * Battery failsafe mode
  *

src/modules/sensors/parameters.cpp

@@ -90,6 +90,7 @@ int initialize_parameter_handles(ParameterHandles &parameter_handles)
 	parameter_handles.rc_map_acro_sw = param_find("RC_MAP_ACRO_SW");
 	parameter_handles.rc_map_offboard_sw = param_find("RC_MAP_OFFB_SW");
 	parameter_handles.rc_map_kill_sw = param_find("RC_MAP_KILL_SW");
+	parameter_handles.rc_map_arm_sw = param_find("RC_MAP_ARM_SW");
 	parameter_handles.rc_map_trans_sw = param_find("RC_MAP_TRANS_SW");
 	parameter_handles.rc_map_gear_sw = param_find("RC_MAP_GEAR_SW");
 
@@ -120,6 +121,7 @@ int initialize_parameter_handles(ParameterHandles &parameter_handles)
 	parameter_handles.rc_acro_th = param_find("RC_ACRO_TH");
 	parameter_handles.rc_offboard_th = param_find("RC_OFFB_TH");
 	parameter_handles.rc_killswitch_th = param_find("RC_KILLSWITCH_TH");
+	parameter_handles.rc_armswitch_th = param_find("RC_ARMSWITCH_TH");
 	parameter_handles.rc_trans_th = param_find("RC_TRANS_TH");
 	parameter_handles.rc_gear_th = param_find("RC_GEAR_TH");
 
@@ -313,6 +315,10 @@ int update_parameters(const ParameterHandles &parameter_handles, Parameters &par
 		PX4_WARN("%s", paramerr);
 	}
 
+	if (param_get(parameter_handles.rc_map_arm_sw, &(parameters.rc_map_arm_sw)) != OK) {
+		PX4_WARN("%s", paramerr);
+	}
+
 	if (param_get(parameter_handles.rc_map_trans_sw, &(parameters.rc_map_trans_sw)) != OK) {
 		PX4_WARN("%s", paramerr);
 	}
@@ -365,6 +371,9 @@ int update_parameters(const ParameterHandles &parameter_handles, Parameters &par
 	param_get(parameter_handles.rc_killswitch_th, &(parameters.rc_killswitch_th));
 	parameters.rc_killswitch_inv = (parameters.rc_killswitch_th < 0);
 	parameters.rc_killswitch_th = fabs(parameters.rc_killswitch_th);
+	param_get(parameter_handles.rc_armswitch_th, &(parameters.rc_armswitch_th));
+	parameters.rc_armswitch_inv = (parameters.rc_armswitch_th < 0);
+	parameters.rc_armswitch_th = fabs(parameters.rc_armswitch_th);
 	param_get(parameter_handles.rc_trans_th, &(parameters.rc_trans_th));
 	parameters.rc_trans_inv = (parameters.rc_trans_th < 0);
 	parameters.rc_trans_th = fabs(parameters.rc_trans_th);

src/modules/sensors/parameters.h

@@ -83,6 +83,7 @@ struct Parameters {
 	int rc_map_acro_sw;
 	int rc_map_offboard_sw;
 	int rc_map_kill_sw;
+	int rc_map_arm_sw;
 	int rc_map_trans_sw;
 	int rc_map_gear_sw;
 
@@ -108,6 +109,7 @@ struct Parameters {
 	float rc_acro_th;
 	float rc_offboard_th;
 	float rc_killswitch_th;
+	float rc_armswitch_th;
 	float rc_trans_th;
 	float rc_gear_th;
 	bool rc_assist_inv;
@@ -119,6 +121,7 @@ struct Parameters {
 	bool rc_acro_inv;
 	bool rc_offboard_inv;
 	bool rc_killswitch_inv;
+	bool rc_armswitch_inv;
 	bool rc_trans_inv;
 	bool rc_gear_inv;
 
@@ -159,6 +162,7 @@ struct ParameterHandles {
 	param_t rc_map_acro_sw;
 	param_t rc_map_offboard_sw;
 	param_t rc_map_kill_sw;
+	param_t rc_map_arm_sw;
 	param_t rc_map_trans_sw;
 	param_t rc_map_gear_sw;
 
@@ -188,6 +192,7 @@ struct ParameterHandles {
 	param_t rc_acro_th;
 	param_t rc_offboard_th;
 	param_t rc_killswitch_th;
+	param_t rc_armswitch_th;
 	param_t rc_trans_th;
 	param_t rc_gear_th;
 

src/modules/sensors/rc_update.cpp

@@ -414,6 +414,8 @@ RCUpdate::rc_poll(const ParameterHandles &parameter_handles)
 						 _parameters.rc_offboard_th, _parameters.rc_offboard_inv);
 			manual.kill_switch = get_rc_sw2pos_position(rc_channels_s::RC_CHANNELS_FUNCTION_KILLSWITCH,
 					     _parameters.rc_killswitch_th, _parameters.rc_killswitch_inv);
+			manual.arm_switch = get_rc_sw2pos_position(rc_channels_s::RC_CHANNELS_FUNCTION_KILLSWITCH,
+					    _parameters.rc_armswitch_th, _parameters.rc_armswitch_inv);
 			manual.transition_switch = get_rc_sw2pos_position(rc_channels_s::RC_CHANNELS_FUNCTION_TRANSITION,
 						   _parameters.rc_trans_th, _parameters.rc_trans_inv);
 			manual.gear_switch = get_rc_sw2pos_position(rc_channels_s::RC_CHANNELS_FUNCTION_GEAR,

src/modules/sensors/sensor_params.c

@@ -2488,6 +2488,34 @@ PARAM_DEFINE_INT32(RC_MAP_OFFB_SW, 0);
  */
 PARAM_DEFINE_INT32(RC_MAP_KILL_SW, 0);
 
+/**
+ * Arm switch channel
+ *
+ * @min 0
+ * @max 18
+ * @group Radio Switches
+ * @value 0 Unassigned
+ * @value 1 Channel 1
+ * @value 2 Channel 2
+ * @value 3 Channel 3
+ * @value 4 Channel 4
+ * @value 5 Channel 5
+ * @value 6 Channel 6
+ * @value 7 Channel 7
+ * @value 8 Channel 8
+ * @value 9 Channel 9
+ * @value 10 Channel 10
+ * @value 11 Channel 11
+ * @value 12 Channel 12
+ * @value 13 Channel 13
+ * @value 14 Channel 14
+ * @value 15 Channel 15
+ * @value 16 Channel 16
+ * @value 17 Channel 17
+ * @value 18 Channel 18
+ */
+PARAM_DEFINE_INT32(RC_MAP_ARM_SW, 0);
+
 /**
  * Flaps channel
  *
@@ -2985,6 +3013,24 @@ PARAM_DEFINE_FLOAT(RC_OFFB_TH, 0.5f);
  */
 PARAM_DEFINE_FLOAT(RC_KILLSWITCH_TH, 0.25f);
 
+/**
+ * Threshold for the arm switch
+ *
+ * 0-1 indicate where in the full channel range the threshold sits
+ * 		0 : min
+ * 		1 : max
+ * sign indicates polarity of comparison
+ * 		positive : true when channel>th
+ * 		negative : true when channel<th
+ *
+ * @min -1
+ * @max 1
+ * @group Radio Switches
+ *
+ *
+ */
+PARAM_DEFINE_FLOAT(RC_ARMSWITCH_TH, 0.25f);
+
 /**
  * Threshold for the VTOL transition switch
  *