遠端鍵盤控制自走車＋WebCam

透過遠端SSH連線，直接執行程式並手動控制自走車的行進與轉彎，有了這個功能，只要網路是通的，遠在天邊也可以控制家裡的自走車並且看見家裡的情況。這次一併介紹getkey這個非常方便使用的鍵盤掃描程式庫。

# -*- coding: UTF-8 -*-
# 自走車馬達類別
import time
import RPi.GPIO as GPIO
from getkey import getkey, keys


class Motor:
    def __init__(self, ena, in1, in2, enb, in3, in4):
        self.ENA = ena
        self.IN1 = in1
        self.IN2 = in2
        self.ENB = enb
        self.IN3 = in3
        self.IN4 = in4
        # 設定右輪
        GPIO.setup(self.ENA, GPIO.OUT, initial=GPIO.LOW)
        # 利用PWN來改變車子馬達轉速（改變車子速度），初始值為全速100
        self.ENA_SPEED = GPIO.PWM(self.ENA, 600)
        self.ENA_SPEED.start(0)
        self.ENA_SPEED.ChangeDutyCycle(100)
        GPIO.setup(self.IN1, GPIO.OUT, initial=GPIO.LOW)
        GPIO.setup(self.IN2, GPIO.OUT, initial=GPIO.LOW)
        # 設定左輪
        GPIO.setup(self.ENB, GPIO.OUT, initial=GPIO.LOW)
        self.ENB_SPEED = GPIO.PWM(self.ENB, 600)
        self.ENB_SPEED.start(0)
        self.ENB_SPEED.ChangeDutyCycle(100)
        GPIO.setup(self.IN3, GPIO.OUT, initial=GPIO.LOW)
        GPIO.setup(self.IN4, GPIO.OUT, initial=GPIO.LOW)

    def right_speed(self, speed):
        self.ENA_SPEED.ChangeDutyCycle(speed)

    def left_speed(self, speed):
        self.ENB_SPEED.ChangeDutyCycle(speed)

    def speed(self, speed):
        self.right_speed(speed)
        self.left_speed(speed)

    def forward(self):
        GPIO.output(self.ENA, True)
        GPIO.output(self.ENB, True)
        GPIO.output(self.IN1, True)
        GPIO.output(self.IN2, False)
        GPIO.output(self.IN3, True)
        GPIO.output(self.IN4, False)

    def backward(self):
        GPIO.output(self.ENA, True)
        GPIO.output(self.ENB, True)
        GPIO.output(self.IN1, False)
        GPIO.output(self.IN2, True)
        GPIO.output(self.IN3, False)
        GPIO.output(self.IN4, True)

    def turn_left(self):
        GPIO.output(self.ENA, True)
        GPIO.output(self.ENB, True)
        GPIO.output(self.IN1, True)
        GPIO.output(self.IN2, False)
        GPIO.output(self.IN3, False)
        GPIO.output(self.IN4, False)

    def turn_right(self):
        GPIO.output(self.ENA, True)
        GPIO.output(self.ENB, True)
        GPIO.output(self.IN1, False)
        GPIO.output(self.IN2, False)
        GPIO.output(self.IN3, True)
        GPIO.output(self.IN4, False)

    def stop(self):
        GPIO.output(self.ENA, True)
        GPIO.output(self.ENB, True)
        GPIO.output(self.IN1, False)
        GPIO.output(self.IN2, False)
        GPIO.output(self.IN3, False)
        GPIO.output(self.IN4, False)

GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)
motor = Motor(13, 19, 16, 20, 21, 26)
motor_speed = 100
while True:
    motor.speed(motor_speed)
    key = getkey()
    if key == keys.UP:
        print('forward')
        motor.forward()
    elif key == keys.DOWN:
        print('backward')
        motor.backward()
    elif key == keys.LEFT:
        print('turn left')
        motor.turn_left()
    elif key == keys.RIGHT:
        print('turn right')
        motor.turn_right()
    elif key == 'l':
        motor_speed -= 10
        if motor_speed <= 30:
            motor_speed = 30
    elif key == 'h':
        motor_speed += 10
        if motor_speed >= 100:
            motor_speed = 100
    elif key == 's':
        motor.stop()
    elif key == keys.ESCAPE:
        motor.stop()
        break