Raspberry pi 4 通过用于机器人汽车的 USB 串行到 arduino答案

【问题标题】：Raspberry pi 4 to arduino via usb Serial for robot carRaspberry pi 4 通过用于机器人汽车的 USB 串行到 arduino
【发布时间】：2020-12-09 19:42:38
【问题描述】：

我正在尝试使用带摄像头、Arduino 和 l298n 电机驱动器的 Raspberry Pi 编写线路跟随器汽车。我正在尝试让 Raspberry Pi 使用 USB 串行与 Arduino 进行通信，但我有点挣扎。

这是我为 Arduino 准备的代码：

#define leftEnable 6    // EnA
#define leftReverse 8   // IN1
#define leftForward 9   // IN2
#define rightEnable 5   //EnB
#define rightReverse 11 //IN4
#define rightForward 10 //IN3

void setup() { // put your setup code here, to run once:
  pinMode(leftEnable, OUTPUT);
  pinMode(rightEnable, OUTPUT);
  pinMode(leftReverse, OUTPUT);
  pinMode(rightReverse, OUTPUT);
  pinMode(leftForward, OUTPUT);
  pinMode(rightForward, OUTPUT);

  // Configure for forward direction only
  digitalWrite(leftReverse, LOW);
  digitalWrite(rightReverse, LOW);
  digitalWrite(leftForward, HIGH);
  digitalWrite(rightForward, HIGH);
}

void loop() { // put your main code here, to run repeatedly:
  analogWrite(leftEnable, 255);
  analogWrite(rightEnable, 255);
  delay(1000);

  // Slow down
  analogWrite(leftEnable, 200);
  analogWrite(rightEnable, 200);
  delay(1000);

  //stop
  analogWrite(leftEnable, 0);
  analogWrite(rightEnable, 0);
  delay(2000);

  //turn right
  analogWrite(leftEnable, 255);
  analogWrite(rightEnable, 0);
  delay(1000);

  analogWrite(leftEnable, 0);
  analogWrite(rightEnable, 255);
  delay(1000);
}

对于覆盆子：

import serial
import time
import numpy as np
import cv2
from picamera import PiCamera

with PiCamera() as src:
 src.resolution = (640,480)
 src.framerate = 20
 src.shutter_speed = 75000
 output = np.empty((480,640, 3), dtype=np.uint8)

 while(True):
 start_time = time.time()
 src.capture(output, format='bgr', use_video_port=True)
 gray = cv2.cvtColor(output, cv2.COLOR_BGR2GRAY)
 gray[gray < 50] =0
 gray[gray > 50] = 255
 top_center = np.average(np.where(gray[0] ==0 ))
 bottom_center = np.average(np.where(gray[-1] ==0))

 if top_center - bottom_center > 25:
 print("Turn right")
 elif top_center - bottom_center <-25:
 print("Turn left")
 else:
 print("Stay on course")

 cv2.imshow('Output', output)
 key = cv2.waitKey(1)&0xFF

 if key==ord("q"):
 break

 cv2.waitKey(8)
 cv2.destroyAllWindows()

【问题讨论】：

提示：删除所有无关的空行。它使您的代码滚动并且更难理解。
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标签： python c++ arduino raspberry-pi

【解决方案1】：

您缺少两端的串行端口命令。在树莓派上像这样向串口发送命令

ser = serial.Serial()
ser.baudrate = 19200
ser.port = '/dev/ttyACM0'
ser.write(b'L') # send codes like 'L' for left,;'R' for Right

像这样在 arduino 上读取命令

void setup() {
  // initialize serial:
  Serial.begin(19200);
}

void loop() {
  while (Serial.available() > 0) {
    if (Serial.read() == 'L'){
      // write code for left turn
    }
  }
}

【讨论】：