Use uBit to control rctoy + rpi via BLE

rc-driver.py

"""
© 2017 [email protected]
Module rpidriver.py - rpi library to handle dc motor
driven rc car using uBit controller
The program reads the Accelerometer:x,y,z values
coming from uBit via BLE and control motor using it
"""

import sys
import time
import math
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BOARD)  #set GPIO to board mode
from bluezero import microbit

IN1 = 11    # Digital IN1 on L298n Board
IN2 = 13    # Digital IN2 on L298n Board
ENA = 12    # PWM GPIO18 to ENA on L298n Board
IN3 = 3     # Digital IN3 on L298n Board
IN4 = 5     # Digital IN4 on L298n Board
ENB = 7     # Digital to ENB on L298n Board

# Setup forward/backward motor
GPIO.setup(IN1, GPIO.OUT)
GPIO.setup(IN2, GPIO.OUT)
GPIO.setup(ENA, GPIO.OUT)
pwm = GPIO.PWM(ENA, 100)
pwm.start(0)
# Setup left/right motor
GPIO.setup(IN3, GPIO.OUT)
GPIO.setup(IN4, GPIO.OUT)
GPIO.setup(ENB, GPIO.OUT)

class Driver:
	def __init__(self, triggerpin):
		self.tpin = triggerpin
		self.ubit = None

	def initialize(self):
		if self.ubit is None:
			self.ubit = microbit.Microbit(adapter_addr='##:##:##:##:##:##', device_addr='##:##:##:##:##:##')
		return self.connect()

	def kill(self):
		try:
        		self.ubit.disconnect()
			self.ubit = None
		except:
			self.ubit = None
		return False

	def connect(self):
		self.dir = 0		# 0 = straight, 1 = right, -1 = left
		self.motion = 0		# 0 = stop, 1 = reverse, -1 = forward
		# Now connect to uBit
		print('Connecting to uBit', file=sys.stderr)
		try:
			self.ubit.connect()
			return True
		except:
			print('No BLE connection yet', file=sys.stderr)
			return False

	def command(self, action):
		if self.ubit.button_a > 0:
			return self.start()
		elif self.ubit.button_b > 0:
			return self.stop()
		else:
			return action

	def start(self):
		self.ubit.pixels =  [0b01110,
				     0b11000,
				     0b01111,
				     0b00011,
				     0b01110]
		time.sleep(0.25)
		return True

	def stop(self):
		self.ubit.pixels =  [0b10001,
				     0b01010,
				     0b00100,
				     0b01010,
				     0b10001]
		time.sleep(0.25)
		return False

	def acceldata(self):
		return self.ubit.accelerometer

	def move(self, x, y):
		if x > 0.2:
			self.right()
		elif x < -0.2:
			self.left()
		else:
			self.straight()

		if y > 0.2:
			dc = math.floor((y - 0.15) * 100 / 1.5)
			self.reverse(dc)
		elif y < -0.2:
			dc = math.floor((abs(y) - 0.15) * 100 / 1.5)
			self.forward(dc)
		else:
			dc = 0
			self.stall()
#		print('Direction: {} | Motion: {} | Power: {}'.format(self.dir, self.motion, dc), file=sys.stderr)

	def right(self):
		if self.dir != 1:
			self.dir = 1
			GPIO.output(IN3, True)
			GPIO.output(IN4, False)
		GPIO.output(ENB, True)

	def left(self):
		if self.dir != -1:
			self.dir = -1
			GPIO.output(IN3, False)
			GPIO.output(IN4, True)
		GPIO.output(ENB, True)

	def straight(self):
		self.dir = 0
		GPIO.output(IN3, False)
		GPIO.output(IN4, False)
		GPIO.output(ENB, False)

	def reverse(self, dc):
		if self.motion != 1:
			self.motion = 1
			GPIO.output(IN1, True)
			GPIO.output(IN2, False)
		pwm.ChangeDutyCycle(dc)
		GPIO.output(ENA, True)

	def forward(self, dc):
		if self.motion != -1:
			self.motion = -1
			GPIO.output(IN1, False)
			GPIO.output(IN2, True)
		pwm.ChangeDutyCycle(dc)
		GPIO.output(ENA, True)

	def stall(self):
		self.motion = 0
		GPIO.output(ENA, False)

rc-main.py

"""
© 2017 [email protected]
Main program to run in background listening for
rc commands
"""

import driver as driver
import signal
import sys
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BOARD)  #set GPIO to board mode
GPIO.setwarnings(False)
GPIO.setup(15, GPIO.IN, pull_up_down=GPIO.PUD_UP)   #use to trigger action
GPIO.setup(16, GPIO.OUT)

# Handle interrupt
def signal_handler(signal, frame):
	print('You pressed Ctrl+C exiting!')
	driver.kill()
	GPIO.cleanup()
	sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)

print("START!! Press Ctrl+C to exit", file=sys.stderr)
status = False
move = False
driver = driver.Driver(15)      #create a driver class with triggerpin
try:
	while True:
		if not status and GPIO.input(15):
			GPIO.output(16, GPIO.HIGH)	#indicate that it is on
			status = driver.initialize()
			print("Switched on...status={}".format(status), file=sys.stderr)
		elif status and not GPIO.input(15):
			GPIO.output(16, GPIO.LOW)	#indicate that it is off
			status = driver.kill()
			print("Switched off...status={}".format(status), file=sys.stderr)
		if status:
			move = driver.command(move)
			x, y, z = driver.acceldata()
			print('move = {}, X = {}, Y = {}, Z = {}'.format(move,x,y,z))
			if move:
				driver.move(x, y)
				
 
except KeyboardInterrupt:       # If CTRL+C is pressed, exit cleanly
        print("You pressed Ctrl+C, exiting...", file=sys.stderr)
        GPIO.cleanup()
finally:
        GPIO.cleanup()