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Diffstat (limited to 'System_Python/system_LOCAL_2371.py')
-rw-r--r-- | System_Python/system_LOCAL_2371.py | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/System_Python/system_LOCAL_2371.py b/System_Python/system_LOCAL_2371.py new file mode 100644 index 0000000..ff38628 --- /dev/null +++ b/System_Python/system_LOCAL_2371.py @@ -0,0 +1,100 @@ +#!/usr/bin/env python
+from motor import Motor
+from encoder import Encoder
+import math
+
+# IO pin definitions
+### Motor pins
+motor_speed_pin = 17
+motor_forward_pin = 27
+motor_reverse_pin = 22
+### Encoder pins (shared by both encoders)
+encoder_clock_pin = 2
+encoder_data_pin = 3
+### Angular encoder pins
+encoder_angular_cs_pin = 4
+### Linear encoder pins
+encoder_linear_cs_pin = 5
+
+
+# System Class
+# This is the primary interface a student will use to control the pendulum.
+class System:
+ def __init__(self):
+ # Initialize the motor.
+ self.motor = Motor(motor_speed_pin, motor_forward_pin, motor_reverse_pin)
+ # Initialize the angular encoder.
+ self.encoder_angular = Encoder(encoder_clock_pin, encoder_angular_cs_pin, encoder_data_pin)
+ self.encoder_angular.set_zero()
+ # Initialize the linear encoder.
+ self.encoder_linear = Linear_Encoder(encoder_clock_pin, encoder_linear_cs_pin, encoder_data_pin)
+ self.encoder_linear.set_zero()
+ # END __init__()
+
+ # Get the values of the encoders to determine the angular and linear position of the pendulum.
+ # Values are returned as a tuple: (angle, linear).
+ ### angle: 0 indicates the pendulum is exactly straight up.
+ ##### 180 or -180 indicate the pendulum is exactly straight down.
+ ##### Positive values indicate the pendulum is leaning to the right.
+ ##### Negative values indicate the pendulum is leaning to the left.
+ ### linear: 0 indicates the pendulum is exactly in the middle of the track.
+ ##### Positive values indicate the pendulum is right-of-center.
+ ##### Negative values indicate the pendulum is left-of-center.
+ def measure(self):
+ angular_position = self.encoder_angular.read_position('Degrees')
+ if angular_position > 180:
+ angular_position = angular_position - 360
+ linear_position = self.encoder_linear.read_position()
+ return (angular_position, linear_position)
+ # END measure()
+
+ # Adjust the pendulum's linear position using the motor.
+ ### speed: Acceptable values range from -100 to 100 (as a percentage), with 100/-100 being the maximum adjustment speed.
+ ##### Negative values will move the pendulum to the left.
+ ##### Positive values will move the pendulum to the right.
+ def adjust(self, speed):
+ # cap the speed inputs
+ if speed > 100.0:
+ speed = 100.0
+ if speed < -100.0:
+ speed = -100.0
+ # change the motor speed
+ # TODO: Make sure the motor is oriented so that positive speed the correct direction (same for negative). Change the values otherwise.
+ self.motor.coast()
+ self.motor.move(speed)
+ # END adjust()
+# END System
+
+# Linear Encoder class
+# This class is to help with using an absolute encoder for linear position sensing as assembled in the physical system.
+# The function definitions here are the same as with the regular encoder (pseudo-interface).
+class Linear_Encoder:
+ PROPORTION = 14.5
+
+ def __init__(self, clk_pin, cs_pin, data_pin):
+ self.encoder = Encoder(clk_pin, cs_pin, data_pin)
+ self.set_zero()
+ def set_zero(self):
+ # Set the zero position for the encoder
+ self.encoder.set_zero()
+ # Reset the internal position counter
+ self.rotations = 0
+ self.last_position = 0
+ def read_position(self):
+ # Read the position of the encoder
+ position = self.encoder.read_position('Raw')
+ # Compare to last known position
+ # NOTE: For now, assume that we are moving the smallest possible distance (i.e. 5 -> 1 is -4, not 1020)
+ if position - self.last_position > 0:
+ if position < 512 and self.last_position > 512:
+ # We are moving to the right (positive) and have completed a new rotation
+ self.rotations = self.rotations + 1
+ else:
+ if position > 512 and self.last_position < 512:
+ # We are moving to the left (negative) and have completed a new rotation
+ self.rotations = self.rotations - 1
+ # Save the last position for the next calculation
+ self.last_position = position
+ # compute the position based on the system parameters
+ # linear position = (2pi*r)(n) + (2pi*r)(position/1024) = (2pi*r)(n + position/1024) = (pi*d)(n + position/1024)
+ return (PROPORTION)*(self.rotations + position/1024)
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