From 1e298b701fbc1c1048122efc5181fb37eeba2829 Mon Sep 17 00:00:00 2001
From: Raspberry Pi <pi@umn.edu>
Date: Tue, 24 Sep 2019 16:57:14 -0500
Subject: Tested on RPi and minor changes to make it work.

---
 System_Python/motor.py      | 67 +++++++++++++++++++++++++++++++++++++++++++++
 System_Python/test_Motor.py | 26 +++++++++---------
 2 files changed, 80 insertions(+), 13 deletions(-)
 create mode 100644 System_Python/motor.py

(limited to 'System_Python')

diff --git a/System_Python/motor.py b/System_Python/motor.py
new file mode 100644
index 0000000..0f7d891
--- /dev/null
+++ b/System_Python/motor.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+
+# Import required modules
+import RPi.GPIO as GPIO
+
+# Constants: parameters that the caller cannot modify
+# Frequency: We have determined that the optimal frequency for our motor is 1kHz
+pwm_frequency = 1000
+
+# Motor Class
+# This controls the motor at the given IO
+class Motor:
+    def __init__(self, speed_pin, forward_pin, reverse_pin):
+        # Set the board IO (just in case it hasn't been done yet)
+        GPIO.setmode(GPIO.BCM)
+        # Set our variables for the directional pins
+        self.forward_pin = forward_pin
+        self.reverse_pin = reverse_pin
+        # setup the IO
+        GPIO.setup(speed_pin, GPIO.OUT)
+        GPIO.setup(self.forward_pin, GPIO.OUT)
+        GPIO.setup(self.reverse_pin, GPIO.OUT)
+        # Set speed pin as a PWM output
+        self.speed_pwm = GPIO.PWM(speed_pin, pwm_frequency)
+    # END __init__
+        
+    # Move the motor at a given speed, given as a floating point percentage (-100 <= x <= 100)
+    # If speed is less than 0, motor will run in reverse, otherwise it will run forward
+    def Move(self, speed):
+        if speed < -100.0 or speed > 100.0:
+            return
+        # Stop any previous movements
+        self.speed_pwm.stop()
+        # Set the duty cycle for the speed of the motor
+        self.speed_pwm.ChangeDutyCycle(abs(speed))
+        if speed < 0:
+            # Set direction to reverse
+            GPIO.output(self.forward_pin, GPIO.LOW)
+            GPIO.output(self.reverse_pin, GPIO.HIGH)
+        else:
+            # Set the direction to forward
+            GPIO.output(self.forward_pin, GPIO.HIGH)
+            GPIO.output(self.reverse_pin, GPIO.LOW)
+        # Start the PWM output to start moving the motor
+        self.speed_pwm.start(abs(speed))
+    # END Move
+    
+    # Stop the motor from spinning.
+    # To brake the motor, both direction outputs are set to HIGH
+    def Brake(self):
+        # Stop any current PWM signals
+        self.speed_pwm.stop()
+        # Set the direction outputs to brake
+        GPIO.output(self.forward_pin, GPIO.HIGH)
+        GPIO.output(self.reverse_pin, GPIO.HIGH)
+    # END Brake
+        
+    # Set the motor to coast (i.e. Do not provide power to the motor, but still allow it to spin)
+    # To coast the motor, both direction outputs are set to LOW
+    def Coast(self):
+        # Stop any current PWM signals
+        self.speed_pwm.stop()
+        # Set the direction outputs to coast
+        GPIO.output(self.forward_pin, GPIO.LOW)
+        GPIO.output(self.reverse_pin, GPIO.LOW)
+    # END Coast
+    
\ No newline at end of file
diff --git a/System_Python/test_Motor.py b/System_Python/test_Motor.py
index f14af59..600f209 100644
--- a/System_Python/test_Motor.py
+++ b/System_Python/test_Motor.py
@@ -2,22 +2,22 @@ from motor import Motor
 import time
 
 # Decide which pins to hook up to on the Pi before running
-speed_pin = 15
-forward_pin = 16
-reverse_pin = 17
+speed_pin = 17
+forward_pin = 27
+reverse_pin = 22
 
 m = Motor(speed_pin, forward_pin, reverse_pin)
 
 dir = 'ascending'
 speed = 0.0
 while 1:
-	m.Move(speed)
-	if speed >= 100.0:
-		dir = 'descending'
-	elif speed <= -100.0:
-		dir = 'ascending'
-	if dir == 'ascending':
-		speed = speed + 0.5
-	else:
-		speed = speed - 0.5
-	time.sleep(0.1)
\ No newline at end of file
+    m.Move(speed)
+    if speed >= 100.0:
+        dir = 'descending'
+    elif speed <= -100.0:
+        dir = 'ascending'
+    if dir == 'ascending':
+        speed = speed + 0.5
+    else:
+        speed = speed - 0.5
+    time.sleep(0.1)
\ No newline at end of file
-- 
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