12月 17

raspberry pi HC-SR04超声波测距

  所购买的HC-SR04的超声波模块介绍如下:
1、典型工作用电压:5V。
2、超小静态工作电流:小于 2mA。
3、感应角度:不大于 15 度 。
4、探测距离:2cm-400cm
5、高精度:可达 0.3cm。
6、盲区(2cm)超近。

  实测raspberry pi电压4.7V。所以直接测试一下,但是需要获取系统时间和系统处理耗时,测试结果精度不高,可以区三次平均数。

  接线如图:
image

  代码如下:

#!/bin/env python
# -*- coding:utf-8 -*-
# -------------------------------
# Revision:
# Date:        2012-12-11
# Author:      simonzhang
# Email:       simon-zzm@163.com
# Web:         www.simonzhang.net
# ------------------------------- 
import time
import RPi.GPIO as GPIO
import datetime as dt

# 初始化
# 需要注意输出与输入的接口
# 17为发射,18为接收
GPIO.setmode(GPIO.BCM)
GPIO.setup(17, GPIO.OUT)
GPIO.setup(18, GPIO.IN)
GPIO.output(17, False)

while  1:
   time.sleep(1)
   # IO 触发,给10us的高电平
   # 模块自动发送8个40khz的方波
   GPIO.output(17, GPIO.HIGH)
   time.sleep(0.00001)
   GPIO.output(17, GPIO.LOW)
   # 获取发射完毕时间
   t1 = time.time()
   # 未接收为False,循环检查开始接受点
   # 转为True为开始接受
   while GPIO.input(18) == False:
       pass
   # 循环检查开始接收,转为False。则为接受完毕
   while GPIO.input(18):
       pass
   # 获取接受完毕时间
   t2 = time.time()
   # 计算发送与接收时间差
   t3 = t2-t1
   print t3
   # 空气中1个标准大气压在温度15度时速度为340m/s
   # 25度为346m/s
   # 所以按照一秒钟34000厘米计算
   # 根据硬件文档,该模块探测距离在2-400cm之间
   # 测试范围的时间间隔应该为0.000117到0.023529
   # 为了方便取值自行变化一点
   if 0.0235 > t3 > 0.00015:
       distance = t3*34000/2
       print 'Distance: %f cm' % distance
   else:
       print 'Null'

raspberry pi HC-SR04超声波测距

12月 15

raspberry pi GPIO 控制步进电机

  其它部分的工具(python-setuptools,python-dev)已经在初始化时安装。现在安装GPIO
sudo easy_install RPi.GPIO

  需要在root权限下调用。如果不想使用管理权限,也可以用第三方的WiringPi,使用easy_install直接安装。
  接上步进电机和驱动板。
image
板子是V2.0的,内存512M的,使用GPIO图如下:
Raspberry-Pi-GPIO-Layout-Revision-2

#!/bin/env python
# -*- coding:utf-8 -*-
# Revision:
# Date:        2012-12-11
# Author:      simonzhang
# Email:       simon-zzm@163.com
# Web:         www.simonzhang.net
# ------------------------------- 
import time
import RPi.GPIO as GPIO

#要使用的四个针脚
Pins = [17,18,22,23]

#初始化。使用BCM2835标准。具体对应要查说明
#http://elinux.org/RPi_BCM2835_GPIOs
GPIO.setmode(GPIO.BCM)
for pin in Pins:
    try:
        GPIO.setup(pin, GPIO.OUT)
        GPIO.output(pin, False)
    except:
        pass

# 顺时针旋转矩阵
Seq1 = []
Seq1 = range(0, 4)
Seq1[0] = [1,0,0,0]
Seq1[1] = [0,1,0,0]
Seq1[2] = [0,0,1,0]
Seq1[3] = [0,0,0,1]

# 逆时针旋转矩阵
Seq2 = []
Seq2 = range(0, 4)
Seq2[0] = [0,0,0,1]
Seq2[1] = [0,0,1,0]
Seq2[2] = [0,1,0,0]
Seq2[3] = [1,0,0,0]

#初始化步数
setup_count = 0
while 1:
  for set in range(0, 4):
      # 小于100步按照逆时针转,100步到200步之间按顺时针转
      print "setup %s" % setup_count
      if 100 < setup_count < 200:
          l = Seq1[set]
      else:
          l = Seq2[set]
      for ls in range(len(Pins)):
          if l[ls] == 1:
              GPIO.output(Pins[ls], True)
          else:
              GPIO.output(Pins[ls], False)
      # 大于200步初始化为0,否则加1
      if setup_count < 200:
          setup_count += 1
      else:
          setup_count = 0
      # 需要做一定延迟,最小延迟应该是0.01s
      time.sleep(0.1)

raspberry pi GPIO 控制步进电机 python 源码

12月 11

raspberry pi 自动初始化脚本

  玩了几天,打算刷一下。但是很多要升级也挺麻烦,直接写了个脚本,自动升级。大家如果还有自己需要的,也可以自行添加,这样初始就方便多了。
  先修改成亚洲的源
$ sudo mv /etc/apt/sources.list /etc/apt/sources.list.bak
$ sudo vi /etc/apt/sources.list
deb http://mirror.nus.edu.sg/raspbian/raspbian wheezy main contrib non-free rpi
deb http://mirrors.tuna.tsinghua.edu.cn/raspbian/raspbian/ wheezy main contrib non-free rpi

  如果直接用我的脚本命令如下:
$ wget http://www.simonzhang.net/wp-content/uploads/2012/12/pisystemupdate.py_.gz
$ gunzip pisystemupdate.py_.gz ;chmod a+x pisystemupdate.py_;python pisystemupdate.py_
不知道为什么加了个尾巴

  脚本内容如下:

#!/bin/env python
# -*- coding:utf-8 -*-
# Revision:
# Date:        2012-12-10
# Author:      simonzhang
# Email:       simon-zzm@163.com
# Web:         www.simonzhang.net
# -------------------------------
import os
import time

def SystemUpdate():   #系统升级
    try:
        os.system('sudo apt-get -y update')
        _get = 'ok'
    except:
        _get = 'ERROR'
    return _get

def Timing():   #校时
    try:
        os.system('sudo cp /usr/share/zoneinfo/Asia/Shanghai  /etc/localtime')
        os.system('sudo apt-get install -y ntpdate')
        os.system('sudo /usr/sbin/ntpdate stdtime.gov.hk')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def Vncserver():    #远程桌面
    try:
        os.system('sudo apt-get install -y tightvncserver') 
        _get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def DevelopTool():    #开发工具
    try:
        os.system('sudo apt-get install -y gcc make')
        _get = 'ok'
    except:
        _get = 'ERROR'
    return _get

def SystemTools():    #系统常用工具
    try:
        os.system('sudo apt-get install -y bison gawk vim chkconfig') 
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def PythonTools():   #python 管理工具
    try:
        os.system('wget -q http://peak.telecommunity.com/dist/ez_setup.py')
        os.system('sudo python ez_setup.py')
        os.system('sudo easy_install pygame')
        _get = 'ok'
    except:
        _get = 'ERROR'
    return _get

	
def PythonImage():    #python的图片处理
    try:
	os.system('sudo apt-get install -y libjpeg*-dev')
	os.system('sudo apt-get install -y python-imaging') 
	os.system('sudo apt-get install -y python-dev')
	os.system('sudo easy_install tornado PIL')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def PythonFrame():    #python框架
    try:
        os.system('sudo easy_install tornado Django')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get

def OpenCV():   #摄像头
    try:
        os.system('sudo apt-get install -y python-opencv')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def InstallMysql():   #数据库,密码为pi
    try:
	os.system('sudo debconf-set-selections <<< \'mysql-server-5.5 mysql-server/root_password password pi\'')
	os.system('sudo debconf-set-selections <<< \'mysql-server-5.5 mysql-server/root_password_again password pi\'')
	os.system('sudo apt-get -y install mysql-server')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get


def Installjava():   #java环境
    try:
	os.system('sudo apt-get install -y openjdk-7-jdk')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get

def ChineseFont():   #中文字体
    try:
	os.system('sudo apt-get install -y ttf-wqy-microhei')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get
	
def InputMethod():   #输入法
    try:
	os.system('sudo apt-get install -y scim scim-pinyin')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get

	
def AudioDriver():   #音频
    try:
        os.system('sudo apt-get install -y alsa-utils')
        os.system('sudo modprobe snd_bcm2835')
	_get = 'ok'
    except:
        _get = 'ERROR'
    return _get

	
def main():
    install_list = [SystemUpdate, \
                    Timing, \
                    Vncserver, \
                    DevelopTool, \
                    SystemTools, \
                    PythonTools, \
                    PythonImage, \
                    PythonFrame, \
                    OpenCV, \
                    InstallMysql, \
                    Installjava, \
                    ChineseFont, \
                    InputMethod,  \
                    AudioDriver, \
                    SystemUpdate,
                   ]
    for il in install_list:
        print '*' * 50
        print ': %s start' % il
        print '*' * 50
        install_status = il()
        nt = time.localtime()
        log_time = "%s-%s-%s %s:%s:%s" % (nt[2], nt[2], nt[3], nt[4], nt[5], nt[6])
        log_file = open("pi_install.log", "ab")
        log_file.write("%s %s install %s\n" % (log_time, il, install_status))
        log_file.close()
    os.system('sudo apt-get upgrade -y')
    print "Install all end."


if __name__ == '__main__':
    main()

pisystemupdate.py

12月 07

raspberry pi连接摄像头

  安装pygame产生窗口用,cv获取摄像头图像
$ sudo easy_install pygame
$ sudo apt-get install -y python-opencv

代码如下:

#!/bin/env python
# -*- coding:utf-8 -*-
# -------------------------------
# Filename:   
# Revision:
# Date:        2012-12-7
# Author:      simonzhang
# Email:       simon-zzm@163.com
# Web:         www.simonzhang.net
# -------------------------------
import pygame
import cv

pygame.init()
size = width, height = 640, 480
speed = [1, 1]  
black = 0, 0, 0  
  
pygame.display.set_caption('simonzhag.net')
screen = pygame.display.set_mode(size)

cam = cv.CreateCameraCapture(0)
cv.SetCaptureProperty(cam,cv.CV_CAP_PROP_FRAME_WIDTH, 640)
cv.SetCaptureProperty(cam,cv.CV_CAP_PROP_FRAME_HEIGHT, 480);

while 1:
    try:
        cv.GrabFrame(cam)
        img = cv.RetrieveFrame(cam)
        cv.SaveImage('/tmp/test.jpg', img)
    except:
        pass
    cv.WaitKey(1500)
    image = pygame.image.load('/tmp/test.jpg')
    screen.blit(image, speed)
    pygame.display.flip()

image

  如果cv.WaitKey过小或者请求太多会报select timeout。还不知道是摄像头问题、还是我的存储开始class2的问题。图像也经常获取不全,问题还未处理。
  也不是所有设想头都可以用。可以使用lsusb查看系统是否识别出usb设备,并且有/dev/video0文件。如果有就应该可以获取。

12月 04

python 源码删除注释并编译成字节码

  上线需要,将py的源码中注释删掉,然后编译成字节码,这样加载速度会比较快。写此脚本主要是为了删除注释。当然如果上线不想放py源码,则在最后增加删除源码即可。我把这个代码起名为咕噜咕噜。python 源码删除注释并编译。

#!/bin/env python
# -*- coding:utf-8 -*-
# -------------------------------
# Filename:    
# Revision:
# Date:        2012-12-3
# Author:      simonzhang
# Email:       simon-zzm@163.com
# Web:         www.simonzhang.net 
# -------------------------------
import os
import re
import sys
import shutil
import compileall


def delete_Notes(py_file):
    # 原始文件只读打开,处理文件追加打开
    _tmp_sr_file = open(py_file, "rb").readlines()
    _tmp_de_file = open("%s.swp" % py_file, "ab")
    _skip_status = 0
    _now_line = 0
    _multi_count = 0 
    # 循环处理
    for line in _tmp_sr_file:
        # 跳过前10行,因为我的开头注释有10行
        if _now_line > 10:
            # 获取开头一位和三位
            try:
                _single_row_notes = line.strip()[0]
            except:
                _single_row_notes = ""
            try: 
                _multi_row_notes = line.strip()[0:3]
            except:
                _multi_row_notes = ""
            # 获取行是否为注释
            if _single_row_notes == "#":
                _skip_status = 1
            elif _multi_row_notes == "'''":
                if _multi_count == 0:
                    _skip_status = 1
                    _multi_count = 1
                else:
                    _skip_status = 1
                    _multi_count = 0
            elif _multi_count == 1:
                _skip_status = 1
            else:
                _skip_status = 0
        else:
            _skip_status = 0
        # 判断是否跳过写入
        if _skip_status == 0:
            _tmp_de_file.write(line)
        _now_line += 1
    _tmp_de_file.close()
    # 处理完毕将临时文件处理为原始文件
    shutil.move("%s.swp" % py_file, py_file)
        

def main():
    _get_src_path = sys.argv[1]
    _get_dec_path = sys.argv[2]
    if os.path.exists(_get_src_path):
        # 拷贝原始文件夹
        shutil.copytree(_get_src_path, _get_dec_path)
        # 删除原始文件中的注释
        find_py_file = re.compile(r"^.*\.py$")
        find_walk = os.walk(_get_dec_path)
        for path,dirs,files in find_walk:
            for f in files:
                if find_py_file.search(f):
                    delete_Notes("%s/%s" % (path, f))
        # 编译成字节码
        compileall.compile_dir(_get_dec_path)
    else:
        print "Path Error!"

if __name__ == "__main__":
    main()

使用方法,
gulugulu.py 源码路径 目标路径

python 源码删除注释并编译