一. 外壳
之前没学习过CAD，所以在这里我使用的建模工具是Tinkercad（一个基于浏览器的3D设计和建模程序），学习成本极低，可快速上手
导出图纸，淘宝定制亚克力板，经过漫长的等待，终于在今天收到了
安装完成后的小车
二. Web控制
以下所有代码均已上传至github
安装bottle库
- 安装pip
pip是特定于Python的软件包管理器，没有安装pip的按照下述方式安装，安装了跳过此步
安装pip
sudo apt install python2-pip -y
或者安装pip3
sudo apt install python3-pip -y
我在这里安装的是pip3，以下代码也尽在python3下测试通过
如果系统中只安装了Python2，那么就只能使用pip。
如果系统中只安装了Python3，那么既可以使用pip也可以使用pip3，二者是等价的。
如果系统中同时安装了Python2和Python3，则pip默认给Python2用，pip3指定给Python3用。- 安装bottle
pip3 install bottle
代码
1. 超声波测距模块
# 超声波测距模块 HC-SR04
import RPi.GPIO as GPIO
import time
class Measure(object):
def __init__(self, GPIO_TRIG, GPIO_ECHO) -> None:
super().__init__()
self.GPIO_TRIG = GPIO_TRIG
self.GPIO_ECHO = GPIO_ECHO
GPIO.setmode(GPIO.BCM)
#设置 GPIO 的工作方式 (IN / OUT)
GPIO.setup(GPIO_TRIG, GPIO.OUT)
GPIO.setup(GPIO_ECHO, GPIO.IN)
def getDistance(self):
# 向Trig引脚发送10us的脉冲信号
GPIO.output(self.GPIO_TRIG, True)
time.sleep(0.00001)
GPIO.output(self.GPIO_TRIG, False)
# 开始发送超声波的时刻
while GPIO.input(self.GPIO_ECHO)==0:
pass
startTime=time.time()
# 收到返回超声波的时刻
while GPIO.input(self.GPIO_ECHO)==1:
pass
endTime=time.time()
# 计算距离 距离=(声波的往返时间*声速)/2
timeDelta = endTime - startTime
distance = (timeDelta * 34300) / 2
return round(distance,2)2. 电机驱动模块
# MotorControl.py
# TB6612FNG电机驱动
# 电机控制
import RPi.GPIO as GPIO
'''
self.GPIO_PWM
self.GPIO_IN1
self.GPIO_IN2
self.freq
self.last_pwm
self.pwm
'''
class Motor(object):
def __init__(self, GPIO_PWM, GPIO_IN1, GPIO_IN2, freq=300) -> None:
super().__init__()
self.GPIO_PWM = GPIO_PWM
self.GPIO_IN1 = GPIO_IN1
self.GPIO_IN2 = GPIO_IN2
self.freq = freq
GPIO.setmode(GPIO.BCM)
#GPIO.setwarnings(False)
GPIO.setup(self.GPIO_PWM, GPIO.OUT)
GPIO.setup(self.GPIO_IN1, GPIO.OUT)
GPIO.setup(self.GPIO_IN2, GPIO.OUT)
self.pwm = GPIO.PWM(self.GPIO_PWM, self.freq)
self.last_pwm = 0
self.pwm.start(self.last_pwm)
''' 静态方法 TB6612FNG的STBY引脚
1. GPIO_STBY int BCM编码号
2. status bool 为true则TB6612FNG工作，反之待机 默认为false
'''
@staticmethod
def standby(GPIO_STBY,status=False):
GPIO.setmode(GPIO.BCM)
#GPIO.setwarnings(False)
if status:
GPIO.setup(status, GPIO.OUT)
GPIO.output(status, True)
else:
GPIO.output(status, False)
''' 设置PWM占空比
1. dc 占空比 [0,100]
'''
def __setPWM(self, dc):
if dc != self.last_pwm:
self.pwm.ChangeDutyCycle(dc)
self.last_pwm = dc
''' 启动
1. speed int 范围[-100,100] 正数则正转，负数则反转
'''
def run(self, speed):
if(speed>=0):
GPIO.output(self.GPIO_IN1, False)
GPIO.output(self.GPIO_IN2, True)
self.__setPWM(speed)
else:
GPIO.output(self.GPIO_IN1, True)
GPIO.output(self.GPIO_IN2, False)
self.__setPWM(-speed)
'''停止'''
def stop(self):
GPIO.output(self.GPIO_IN1, False)
GPIO.output(self.GPIO_IN2, False)
self.__setPWM(0)
def cleanup(self):
self.stop()
self.pwm.stop()3. 小车控制
考虑到两个电机的转速可能不完全一致，所以需要一个微调功能。
摄像头模块在DIY树莓派小车（二）树莓派4B安装并使用摄像头和超声波模块中使用motion在8081端口开启了视频输出，可以直接调用，这里不再写有关摄像头模块的代码
# CarControl.py
# 控制小车移动 （前进 后退 左转 右转）
# 驱动：TB6612FNG
import RPi.GPIO as GPIO
from MotorControl import Motor
from Distance import Measure
'''
TB6612FNG 接口
# STBY
GPIO_STBY = 27
# 左边电机
GPIO_PWMA = 18
GPIO_AIN1 = 14
GPIO_AIN2 = 15
# 右边电机
GPIO_PWMB = 19
GPIO_BIN1 = 23
GPIO_BIN2 = 24
HC-SR04 接口
GPIO_TRIG = 5
GPIO_ECHO = 6
小车功能
1. 微调
2. 变速
3. 前进
4. 后退
5. 左转
6. 右转
7. 停车
8. 测距
'''
class Car(object):
def __init__(self) -> None:
super().__init__()
'''电机模块'''
# STBY引脚定义
self.GPIO_STBY = 27
GPIO.setmode(GPIO.BCM)
#GPIO.setwarnings(False)
GPIO.setup(self.GPIO_STBY, GPIO.OUT)
# 左右两个电机
self.motor_left = Motor(18,14,15)
self.motor_right = Motor(19,23,24)
# STBY = True TB6612FNG开始工作
Motor.standby(self.GPIO_STBY,True)
# 速度 占空比
self.motor_speed = 60
self.motor_left_speed = 60
self.motor_right_speed = 60
# 速度系数 用于微调
self.motor_left_coefficient = 1.0
self.motor_right_coefficient = 1.0
'''超声波测距模块'''
self.measure = Measure(5, 6)
# 微调 使两个电机转速一致 left=True向左微调 反之向右
def fineTuning(self, left):
if left:
# 向左微调 左边的电机减速 右边的电机加速
self.motor_left_coefficient -= 0.05
self.motor_right_coefficient += 0.05
else:
# 向右边微调 左边的电机加速 右边的电机减速
self.motor_left_coefficient += 0.05
self.motor_right_coefficient -= 0.05
# 更改速度 [0,100]
def setSpeed(self, speed):
if speed>100:
speed = 100
if speed<0:
speed = 0
self.motor_speed = speed
self.motor_left_speed = self.motor_left_coefficient * speed
self.motor_right_speed = self.motor_right_coefficient * speed
# 前进
def forward(self):
self.motor_left.run(self.motor_left_speed)
self.motor_right.run(self.motor_right_speed)
# 后退
def backward(self):
self.motor_left.run(-self.motor_left_speed)
self.motor_right.run(-self.motor_right_speed)
# 左转
def turnLeft(self):
self.motor_left.run(-self.motor_left_speed)
self.motor_right.run(self.motor_right_speed)
# 右转
def turnRight(self):
self.motor_left.run(self.motor_left_speed)
self.motor_right.run(-self.motor_right_speed)
# 停止
def stop(self):
self.motor_left.stop()
self.motor_right.stop()
# 测距
def getDistance(self):
return self.measure.getDistance()
def getSpeed(self):
return self.motor_speed
# 释放资源
def cleanup(self):
self.motor_left.cleanup()
self.motor_right.cleanup()
GPIO.cleanup()4. 获取树莓派信息
以下代码用于获取树莓派CPU温度、CPU使用率、RAM使用率
# RaspberryInfo.py
# 获取树莓派 CPU温度 内存使用率 CPU使用率
import os
# CPU温度
def getCpuTemp():
res = os.popen('vcgencmd measure_temp').readline()
return(res.replace("temp=","").replace("'C\n",""))
# CPU使用率
def getCpuUsage():
return(str(os.popen("top -n1 | awk '/Cpu\(s\):/ {print $2}'").readline().strip()))
# RAM信息
def getRAMinfo():
p = os.popen('free')
i = 0
while 1:
i = i + 1
line = p.readline()
if i==2:
return(line.split()[1:4])
# 内存使用率
def getRamUsage():
RAM_stats = getRAMinfo()
return round(int(RAM_stats[1]) / int(RAM_stats[0])*100,1)5. 小车Web控制面板
通过按钮或者键盘来控制小车移动
键盘操作方法见下表
| 按键 | W | S | A | D | Q | E | Z | C |
|---|---|---|---|---|---|---|---|---|
| 功能 | 前进 | 后退 | 左转 | 右转 | 加速 | 减速 | 左微调 |
右微调 |
<!-- index.html -->
<!-- 树莓派小车控制面板 -->
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Raspberry Car Control Panel</title>
<link href="http://cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css" rel="stylesheet" media="screen">
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.js"></script>
<style type="text/css">
#front {
margin-left: 55px;
margin-bottom: 3px;
}
#rear{
margin-top: 3px;
margin-left: 55px;
}
.btn{
background: #62559f;
}
</style>
<script>
$(function(){
$("button").mousedown(function(){
console.log(this.id + "mouse down");
$.post("/cmd",this.id,function(data,status){});
});
// 鼠标弹起则停止移动
$("button").mouseup(function(){
console.log(this.id + "mouse up");
$.post("/cmd","stop",function(data,status){});
})
// 键盘控制小车移动
$(document).keydown(function(event){
switch(event.keyCode){
case 87://w
console.log("press W");
$.post("/cmd","forward",function(data,status){});
break;
case 83://s
console.log("press S");
$.post("/cmd","backward",function(data,status){});
break;
case 65://a
console.log("press A");
$.post("/cmd","turnLeft",function(data,status){});
break;
case 68://d
console.log("press D");
$.post("/cmd","turnRight",function(data,status){});
break;
case 81://q
console.log("press Q");
$.post("/cmd","speedUp",function(data,status){});
break;
case 69://e
console.log("press E");
$.post("/cmd","slowDown",function(data,status){});
break;
case 90://z
console.log("press Z");
$.post("/cmd","leftFineTuning",function(data,status){});
break;
case 67://c
console.log("press C");
$.post("/cmd","rightFineTuning",function(data,status){});
break;
}
});
$(document).keyup(function(event){
switch(event.keyCode){
case 87://w
case 83://s
case 65://a
case 68://d
case 81://q
console.log("key up");
$.post("/cmd","stop",function(data,status){});
break;
}
});
});
</script>
</head>
<body>
<div class="row">
<div class="col-xs-12 col-sm-6 col-md-7">
<div class="panel panel-default">
<div class="panel-heading">
<h3 class="panel-title">实时画面</h3>
</div>
<div class="panel-body">
<iframe src="http://192.168.0.100:8081/" width="820" height="620" frameborder="1" name="name" scrolling="auto"></iframe>
</div>
</div>
</div>
<div class="col-xs-6 col-md-4">
<div class="panel panel-default">
<div class="panel panel-default">
<div class="panel-heading">
<h3 class="panel-title">信息</h3>
</div>
<div class="panel-body" >
<iframe id="car-info" width="320" height="195" src="http://192.168.0.100:8088/info"></iframe>
</div>
</div>
<div class="panel-heading">
<h3 class="panel-title">控制</h3>
</div>
<div class="panel-body" style="margin: 30px;margin-left: 40px">
<div class="row" >
<div class="col-md-2"></div>
<div class="col-md-2"><button id="forward" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-top" aria-hidden="true"></span><br/>前进</button></div>
<div class="col-md-2"></div>
</div>
<br/>
<div class="row">
<div class="col-md-2"><button id="turnLeft" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-left" aria-hidden="true"></span><br/>左转</button></div>
<div class="col-md-2"><button id="backward" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-bottom" aria-hidden="true"></span><br/>后退</button></div>
<div class="col-md-2"><button id="turnRight" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-right" aria-hidden="true"></span><br/>右转</button></div>
</div>
<br/>
<div class="row">
<div class="col-md-2"><button id="speedUp" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon glyphicon-plus-sign" aria-hidden="true"></span><br/>加速</button></div>
<div class="col-md-2"></div>
<div class="col-md-2"><button id="slowDown" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon glyphicon-minus-sign" aria-hidden="true"></span><br/>减速</button></div>
</div>
<br>
<div class="row">
<div class="col-md-2"><button id="leftFineTuning" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-left" aria-hidden="true"></span><br/>左微调</button></div>
<div class="col-md-2"></div>
<div class="col-md-2"><button id="rightFineTuning" class="btn btn-large btn-primary" type="button"><span class="glyphicon glyphicon-triangle-right" aria-hidden="true"></span><br/>右微调</button></div>
</div>
</div>
</div>
</div>
</body>
</html>6. 树莓派小车信息页面
此页面嵌入到小车Web控制面板页面中，显示小车速度（PWM占空比）、距离、CPU温度、CPU使用率、内存使用率
此页面1秒刷新一次
<!-- info.html -->
<!-- 树莓派小车信息面板 -->
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<!--每1秒刷新一次-->
<meta http-equiv="refresh" content="1">
<title>信息</title>
</head>
<body>
<p>Speed: {{speed}}</p>
<p>Distance: {{distance}}cm</p>
<p>CPU Temp: {{cpuTemp}}℃</p>
<p>CPU Uasge: {{cpuUsage}}%</p>
<p>RAM Uasge: {{ramUsage}}%</p>
</body>
</html>7. 启动
# Start.py
from bottle import get,post,run,request,template
from CarControl import Car
from RaspberryInfo import *
car = Car()
def main(status):
print("Event: "+status)
if status == "forward":
car.forward()
elif status == "backward":
car.backward()
elif status == "turnLeft":
car.turnLeft()
elif status == "turnRight":
car.turnRight()
elif status == "speedUp":
car.setSpeed(car.getSpeed() + 5)
elif status == "slowDown":
car.setSpeed(car.getSpeed() - 5)
elif status == "leftFineTuning":
car.fineTuning(True)
elif status == "rightFineTuning":
car.fineTuning(False)
elif status == "stop":
car.stop()
# 控制台
@get("/")
def index():
print("request index.html")
return template("index.html")
# 控制小车
@post("/cmd")
def cmd():
adss=request.body.read().decode()
main(adss)
return "OK"
# 小车信息
@get("/info")
def info():
print("Update status Information")
return template("info.html", speed=car.getSpeed(), distance=car.getDistance(), cpuTemp=getCpuTemp(), cpuUsage=getCpuUsage(), ramUsage=getRamUsage())
run(host='0.0.0.0', port=8088, debug=False)
car.cleanup()实测
启动
sudo motion # 打开摄像头
python3 Start.py在浏览器中输入如下Url进入树莓派小车控制页面
http://树莓派ip:8088
Web页面如下，可以通过网页上的按钮或者键盘控制小车（局域网内网络延迟很低，画面几乎实时显示）
控制面板右侧显示的是树莓派小车信息，其中Speed是PWM占空比，范围是[0,100]，Distance是超声波测距的结果
当小车不能走直线时，如果向右偏，则需要使用左微调，反之使用右微调
至此树莓派小车制作完毕
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