Subscribe to Cyphal estop message, relay it into ROS, inform user via…

… BASH output.

include/t07_robot/Node.h

@@ -12,8 +12,10 @@
 
 #include <memory>
 
+#include <rclcpp/qos.hpp>
 #include <rclcpp/rclcpp.hpp>
 
+#include <std_msgs/msg/bool.hpp>
 #include <std_msgs/msg/float32.hpp>
 
 #include <cyphal++/cyphal++.h>
@@ -86,6 +88,12 @@ class Node : public rclcpp::Node
   rclcpp::TimerBase::SharedPtr _motor_right_ctrl_loop_timer;
   void init_motor_right();
   void motor_right_ctrl_loop();
+
+  rclcpp::QoS _estop_qos_profile;
+  rclcpp::Publisher<std_msgs::msg::Bool>::SharedPtr _estop_pub;
+  cyphal::Subscription _estop_cyphal_sub;
+  bool _is_estop_active;
+  void init_estop();
 };
 
 /**************************************************************************************

launch/robot.py

@@ -23,6 +23,10 @@ def generate_launch_description():
         {'motor_right_rpm_port_id': 1001},
         {'wheel_left_diameter_mm': 130.0},
         {'wheel_right_diameter_mm': 130.0},
+        {'estop_topic': '/estop/actual'},
+        {'estop_topic_deadline_ms': 100},
+        {'estop_topic_liveliness_lease_duration': 1000},
+        {'estop_port_id': 100},
       ]
     )
   ])

src/Node.cpp

@@ -36,18 +36,12 @@ Node::Node()
             cyphal::Node::DEFAULT_MTU_SIZE}
 , _node_mtx{}
 , _node_start{std::chrono::steady_clock::now()}
-, _motor_left_qos_profile
-{
-  rclcpp::KeepLast(1),
-  rmw_qos_profile_sensor_data
-}
+, _motor_left_qos_profile{rclcpp::KeepLast(1), rmw_qos_profile_sensor_data}
 , _motor_left_target{0. * m/s}
-, _motor_right_qos_profile
-{
-  rclcpp::KeepLast(1),
-  rmw_qos_profile_sensor_data
-}
+, _motor_right_qos_profile{rclcpp::KeepLast(1), rmw_qos_profile_sensor_data}
 , _motor_right_target{0. * m/s}
+, _estop_qos_profile{rclcpp::KeepLast(1), rmw_qos_profile_default}
+, _is_estop_active{false}
 {
   declare_parameter("can_iface", "can0");
   declare_parameter("can_node_id", 100);
@@ -80,6 +74,7 @@ Node::Node()
 
   init_motor_left();
   init_motor_right();
+  init_estop();
 
   RCLCPP_INFO(get_logger(), "%s init complete.", get_name());
 }
@@ -291,6 +286,46 @@ void Node::motor_right_ctrl_loop()
   }
 }
 
+void Node::init_estop()
+{
+  /* Initialize the ROS publisher. */
+  declare_parameter("estop_topic", "/estop/actual");
+  declare_parameter("estop_topic_deadline_ms", 100);
+  declare_parameter("estop_topic_liveliness_lease_duration", 1000);
+
+  auto const estop_topic = get_parameter("estop_topic").as_string();
+  auto const estop_topic_deadline = std::chrono::milliseconds(get_parameter("estop_topic_deadline_ms").as_int());
+  auto const estop_topic_liveliness_lease_duration = std::chrono::milliseconds(get_parameter("estop_topic_liveliness_lease_duration").as_int());
+
+  _estop_qos_profile.deadline(estop_topic_deadline);
+  _estop_qos_profile.liveliness(RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC);
+  _estop_qos_profile.liveliness_lease_duration(estop_topic_liveliness_lease_duration);
+
+  _estop_pub = create_publisher<std_msgs::msg::Bool>(estop_topic, _estop_qos_profile);
+
+  /* Initialize the Cyphal subscriber. */
+  declare_parameter("estop_port_id", 100);
+
+  _estop_cyphal_sub = _node_hdl.create_subscription<uavcan::primitive::scalar::Bit_1_0>(
+    get_parameter("estop_port_id").as_int(),
+    [this](uavcan::primitive::scalar::Bit_1_0 const & msg)
+    {
+      _is_estop_active = (msg.value == false);
+
+      if (_is_estop_active)
+        RCLCPP_ERROR_THROTTLE(get_logger(), *get_clock(), 5*1000UL, "emergency stop is active.");
+
+      static bool prev_is_estop_active = false;
+      if (!_is_estop_active && prev_is_estop_active)
+        RCLCPP_INFO(get_logger(), "emergency stop was released.");
+      prev_is_estop_active = _is_estop_active;
+
+      std_msgs::msg::Bool estop_msg;
+      estop_msg.data = _is_estop_active;
+      _estop_pub->publish(estop_msg);
+    });
+}
+
 /**************************************************************************************
  * NAMESPACE
  **************************************************************************************/