Improve Module 3 exercise (#40)

* have wrong param definition for both declare and get otherwise we get a misleading error

Signed-off-by: Xavier Ruiz <xavier.ruiz@ekumenlabs.com>

* change the intentional typo ftom sub to pub to improve exercise flow

Signed-off-by: Xavier Ruiz <xavier.ruiz@ekumenlabs.com>

---------

Signed-off-by: Xavier Ruiz <xavier.ruiz@ekumenlabs.com>

Author: xaru8145

modules/module_3/src/laser_detector_node.cpp

@@ -21,8 +21,8 @@ namespace module_3 {
 LaserDetectorNode::LaserDetectorNode(const rclcpp::NodeOptions& options)
     : rclcpp::Node("laser_detector_node", options) {
   // Declare parameters
-  this->declare_parameter("fotprint_radius", 1.0);
-  this->declare_parameter("min_points", 20);
+  this->declare_parameter("footprint_radius", 1.0);
+  this->declare_parameter("min_point", 20);
   this->declare_parameter("roi_min_angle", 0.0);
   this->declare_parameter("roi_max_angle", 2.0 * M_PI);
 
@@ -48,11 +48,11 @@ LaserDetectorNode::LaserDetectorNode(const rclcpp::NodeOptions& options)
   }
 
   // Publishers
-  obstacle_pub_ = this->create_publisher<std_msgs::msg::Bool>("obstacle_detection", 10);
+  obstacle_pub_ = this->create_publisher<std_msgs::msg::Bool>("obstacle_detections", 10);
 
   // Subscribers
   scan_sub_ = this->create_subscription<sensor_msgs::msg::LaserScan>(
-      "scans", rclcpp::SensorDataQoS(),
+      "scan", rclcpp::SensorDataQoS(),
       std::bind(&LaserDetectorNode::scan_callback, this, std::placeholders::_1));
 
   RCLCPP_INFO(this->get_logger(), "LaserDetectorNode initialized");