From 2a5cbeec4ee5ffb58d1d273ee9e82efec7228ecd Mon Sep 17 00:00:00 2001
From: damic014 <damic014@umn.edu>
Date: Mon, 23 Sep 2019 15:18:54 -0500
Subject: Added Motor class

---
 System_Python/Motor.py | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 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..d2e7958
--- /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.BOARD)
+		# 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()
+	# 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
-- 
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