[ADD] Base signal. Exponential.

sample_signal/config/sample_signal.yaml

 /**/sample_signal:
   ros__parameters:
     publisher_frequency:              50.0                     # Hz
+
+    base_signal:                      true
     base_signal_initial_value:        0.0                      
-    base_signal_step:                 0.1
-    sine_wave_components:             [ 2.0,  40.0, 0.0,       # Frequency, amplitude, phase shift(radians) pairs
+    base_signal_step:                 0.01
+    base_signal_exponential:          false
+    exponential_growth_rate:          0.005
+
+    sine_wave:                        false
+    sine_wave_components:             [ 2.0,  20.0, 0.0,       # Frequency, amplitude, phase shift(radians) pairs
                                         10.0, 10.0, 1.57,      # Add as much as needed
-                                        #5.0,  3.0 
-                                      ]
\ No newline at end of file
+                                        #5.0,  3.0, 3.14 
+                                      ]
+
+    square_wave:                      false
+    square_wave_components:           [0.5, 25.0]               # Frequency, amplitude pairs
\ No newline at end of file

sample_signal/sample_signal/sample_signal.py

@@ -14,10 +14,17 @@ class SampleWavePublisher(Node):
         self.declare_parameter('publisher_frequency',            50.0)
         self.declare_parameter('base_signal_initial_value',      0.0)
         self.declare_parameter('base_signal_step',               0.1)
+        self.declare_parameter('square_wave_components',        [0.5, 25.0])
+        self.declare_parameter('base_signal',                   False)
+        self.declare_parameter('base_signal_exponential',       False)
+        self.declare_parameter('sine_wave',                     False)
+        self.declare_parameter('square_wave',                   False)
+        self.declare_parameter('exponential_growth_rate',       0.05) 
 
         self.timer_period = 1/self.get_parameter('publisher_frequency').get_parameter_value().double_value
         self.sine_wave_components = self.get_parameter('sine_wave_components').get_parameter_value().double_array_value
         self.base_signal_value = self.get_parameter('base_signal_initial_value').get_parameter_value().double_value
+        self.square_wave_components = self.get_parameter('square_wave_components').get_parameter_value().double_array_value
 
         self.publisher_ = self.create_publisher(Float32, 'sample_wave', 10)
         self.timer = self.create_timer(self.timer_period, self.timer_callback)
@@ -27,16 +34,34 @@ class SampleWavePublisher(Node):
         msg = Float32() 
         msg.data = 0.0
 
+        if (self.get_parameter('sine_wave').get_parameter_value().bool_value): self.add_sine_component(msg)
+        if (self.get_parameter('square_wave').get_parameter_value().bool_value): self.add_square_component(msg)
+        if (self.get_parameter('base_signal').get_parameter_value().bool_value): self.add_base_signal(msg)
+
+        self.publisher_.publish(msg) 
+        self.time_step += 1.0
+        
+    
+    def add_sine_component(self, msg):
         for i in range(0, len(self.sine_wave_components), 3): 
             sine_frequency = self.sine_wave_components[i] 
             sine_amplitude = self.sine_wave_components[i + 1] 
             phase_shift =    self.sine_wave_components[i + 2] 
-            msg.data += sine_amplitude * np.cos(2 * np.pi * sine_frequency * self.time_step * self.timer_period + phase_shift) + self.base_signal_value
-            
-        self.publisher_.publish(msg) 
-        self.time_step += 1.0
-        self.base_signal_value += self.get_parameter('base_signal_step').get_parameter_value().double_value
+            msg.data += sine_amplitude * np.cos(2 * np.pi * sine_frequency * self.time_step * self.timer_period + phase_shift)
+    
+    def add_square_component(self, msg):
+        for i in range(0, len(self.square_wave_components), 2): 
+            square_frequency = self.square_wave_components[i] 
+            square_amplitude = self.square_wave_components[i + 1] 
+            msg.data += square_amplitude * np.sign(np.sin(2 * np.pi * square_frequency * self.time_step * self.timer_period))
+        
 
+    def add_base_signal(self, msg):
+        if (self.get_parameter('base_signal_exponential').get_parameter_value().bool_value):
+            msg.data = np.exp(self.get_parameter('exponential_growth_rate').get_parameter_value().double_value * self.time_step)
+        else:
+            self.base_signal_value += self.get_parameter('base_signal_step').get_parameter_value().double_value
+            msg.data += self.base_signal_value
 
 def main(args=None):
     rclpy.init(args=args)