Raspberry Pi开发实战

路径

代码语言：javascript复制

framebuffer_width=960
framebuffer_height=540

记住这个参数,改分辨率的~

把系统扩展到所有SD卡

过扫描,黑边.负数都是,从-20开始

超频选项

代码语言：javascript复制

import time


def factorial(n):
    if n == 0:
        return 1
    else:
        return n*factorial(n-1)
    before_time = time.clock()
    for i in range(1, 10000):
        factorial(200)
        after_time = time.clock()
    print(after_time - before_time)

---

顺手写了一段测cpu的代码,感兴趣可以测试一下超频的效果.

录视频,以后讲

看看摄像头sudo apt install nomacs安装这个软件

改名字,就是ip的名字

如果你改了名字/etc/hosts这里也要改

与Mac互相交换文件,安装这个软件

更新服务

代码语言：javascript复制

<?xml version="1.0" standalone='no'?><!--*-nxml-*-->
        <!DOCTYPE service-group SYSTEM "avahi-service.dtd">
<service-group>
              <name replace-wildcards="yes">%h</name>
              <service>
                <type>_afpovertcp._tcp</type>
                <port>548</port>
              </service>
</service-group>

写入这串代码,在下面的文件里面

设置成守护进程

---

然后就可以自由的在mac上面移动文件了~

Ctrl X,退出.在nano推出前提示用户保存wenjian

Ctrl V,下一页,光标下移,允许在一个大文件里面每次移动一个屏幕

Ctrl Y,前一页

Ctrl W查找命令

第一节是权限,文件,所有人,组,大小,修改日期,文件名

sudo apt-get remove xxxxxxx移除软件

sudo apt-get autoremove xxxxxxxx同时移除必备软件包

sudo apt-get clean 进一步进行清理

如何设置一个开机脚本

1. 创建一个init.d脚本
2. 将此脚本标记为可执行
3. 讲此脚本注册到系统

注意,这个脚本要在/etc/init.d/中创建

做个示范,看看

代码语言：javascript复制

### BEGIN INIT INFO
        # Provides: my_server
# Required-Start: $remote_fs $syslog $network
        # Required-Stop: $remote_fs $syslog $network
        # Default-Start: 2 3 4 5
        # Default-Stop: 0 1 6
        # Short-Description: Simple Web Server
        # Description: Simple Web Server
        ### END INIT INFO
        #! /bin/sh
        # /etc/init.d/my_server
        export HOME
        case "$1" in
          start)
            echo "Starting My Server"
            sudo /usr/bin/python /home/pi/myserver.py  2>&1 &
          ;;
        stop)
          echo "Stopping My Server"
          PID=`ps auxwww | grep myserver.py | head -1 | awk '{print $2}'`
          kill -9 $PID
          ;;
        *)
          echo "Usage: /etc/init.d/my_server {start|stop}"
          exit 1
;;
        esac
        exit 0

在里面创建一个my_serve.但是建议在别的地方写好,复制过来这样比较好

设置权限

然后测试了一下是不是可以用,我脚本写的可能有问题.不重要倒是,模板就是这样

先删除

这句是把脚本注册到系统服务

---

可能你还有定时这样的服务,用crontab命令

hsitory的命令

我可以用脚本命令来过滤输出

top监视系统

还是过滤此时所有的python进程

killall是kill的升级版

&可以让任务在后天运行

用fg 命令切回前台

alias命令

写一个

强制生效 此时.成功

df -h有空格,查看磁盘空间

安装motion

在配置文件里面把,这个都打开

写入这个

这是目录

打开服务

啊,这...

我看了下端口,这服务没有开启

---

头疼,,,,nano全选是啥键?????????????????

我的天,没有vim,安装一下

爷自闭了,啥啊....不会用

可视化走起

取出配置文件,翻译一下.超气的!!!!

我有空再研究~

代码语言：javascript复制

        $ mkdir pifm
        $ cd pifm
        $ wget http://www.icrobotics.co.uk/wiki/images/c/c3/Pifm.tar.gz
        $ tar -xzf Pifm.tar.gz

pifm

抱歉,,这个东西我没有插电线.手头也没有好的收音机试不了了

代码语言：javascript复制

// To run:
//  wget -O - http://beta.etherpad.org/p/pihackfm/export/txt 2>/dev/null | gcc -lm -std=c99 -g -xc - && ./a.out beatles.wav
// Access from ARM Running Linux


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <math.h>
#include <fcntl.h>
#include <assert.h>
#include <malloc.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#include <unistd.h>

#define PAGE_SIZE (4*1024)
#define BLOCK_SIZE (4*1024)

int  mem_fd;
char *gpio_mem, *gpio_map;
char *spi0_mem, *spi0_map;


// I/O access
volatile unsigned *gpio;
volatile unsigned *allof7e;

// GPIO setup macros. Always use INP_GPIO(x) before using OUT_GPIO(x) or SET_GPIO_ALT(x,y)
#define INP_GPIO(g) *(gpio ((g)/10)) &= ~(7<<(((g))*3))
#define OUT_GPIO(g) *(gpio ((g)/10)) |=  (1<<(((g))*3))
#define SET_GPIO_ALT(g,a) *(gpio (((g)/10))) |= (((a)<=3?(a) 4:(a)==4?3:2)<<(((g))*3))

#define GPIO_SET *(gpio 7)  // sets   bits which are 1 ignores bits which are 0
#define GPIO_CLR *(gpio 10) // clears bits which are 1 ignores bits which are 0
#define GPIO_GET *(gpio 13)  // sets   bits which are 1 ignores bits which are 0

#define ACCESS(base) *(volatile int*)((int)allof7e base-0x7e000000)
#define SETBIT(base, bit) ACCESS(base) |= 1<<bit
#define CLRBIT(base, bit) ACCESS(base) &= ~(1<<bit)

#define CM_GP0CTL (0x7e101070)
#define GPFSEL0 (0x7E200000)
#define CM_GP0DIV (0x7e101074)
#define CLKBASE (0x7E101000)
#define DMABASE (0x7E007000)
#define PWMBASE  (0x7e20C000) /* PWM controller */


struct GPCTL {
    char SRC         : 4;
    char ENAB        : 1;
    char KILL        : 1;
    char             : 1;
    char BUSY        : 1;
    char FLIP        : 1;
    char MASH        : 2;
    unsigned int     : 13;
    char PASSWD      : 8;
};



void getRealMemPage(void** vAddr, void** pAddr) {
    void* a = valloc(4096);
    
    ((int*)a)[0] = 1;  // use page to force allocation.
    
    mlock(a, 4096);  // lock into ram.
    
    *vAddr = a;  // yay - we know the virtual address
    
    unsigned long long frameinfo;
    
    int fp = open("/proc/self/pagemap", 'r');
    lseek(fp, ((int)a)/4096*8, SEEK_SET);
    read(fp, &frameinfo, sizeof(frameinfo));
    
    *pAddr = (void*)((int)(frameinfo*4096));
}

void freeRealMemPage(void* vAddr) {
    
    munlock(vAddr, 4096);  // unlock ram.
    
    free(vAddr);
}

void setup_fm()
{

    /* open /dev/mem */
    if ((mem_fd = open("/dev/mem", O_RDWR|O_SYNC) ) < 0) {
        printf("can't open /dev/mem n");
        exit (-1);
    }
    
    allof7e = (unsigned *)mmap(
                  NULL,
                  0x01000000,  //len
                  PROT_READ|PROT_WRITE,
                  MAP_SHARED,
                  mem_fd,
                  0x20000000  //base
              );

    if ((int)allof7e==-1) exit(-1);

    SETBIT(GPFSEL0 , 14);
    CLRBIT(GPFSEL0 , 13);
    CLRBIT(GPFSEL0 , 12);

 
    struct GPCTL setupword = {6/*SRC*/, 1, 0, 0, 0, 1,0x5a};

    ACCESS(CM_GP0CTL) = *((int*)&setupword);
}


void modulate(int m)
{
    ACCESS(CM_GP0DIV) = (0x5a << 24)   0x4d72   m;
}

struct CB {
    volatile unsigned int TI;
    volatile unsigned int SOURCE_AD;
    volatile unsigned int DEST_AD;
    volatile unsigned int TXFR_LEN;
    volatile unsigned int STRIDE;
    volatile unsigned int NEXTCONBK;
    volatile unsigned int RES1;
    volatile unsigned int RES2;
    
};

struct DMAregs {
    volatile unsigned int CS;
    volatile unsigned int CONBLK_AD;
    volatile unsigned int TI;
    volatile unsigned int SOURCE_AD;
    volatile unsigned int DEST_AD;
    volatile unsigned int TXFR_LEN;
    volatile unsigned int STRIDE;
    volatile unsigned int NEXTCONBK;
    volatile unsigned int DEBUG;
};

struct PageInfo {
    void* p;  // physical address
    void* v;   // virtual address
};

struct PageInfo constPage;   
struct PageInfo instrPage;
struct PageInfo instrs[1024];


void playWav(char* filename, float samplerate)
{
    int fp= STDIN_FILENO;
    if(filename[0]!='-') fp = open(filename, 'r');
    //int sz = lseek(fp, 0L, SEEK_END);
    //lseek(fp, 0L, SEEK_SET);
    //short* data = (short*)malloc(sz);
    //read(fp, data, sz);
    
    int bufPtr=0;
    float datanew, dataold = 0;
    short data;
    
    for (int i=0; i<22; i  )
       read(fp, &data, 2);  // read past header
    
    while (read(fp, &data, 2)) {
        float fmconstant = samplerate * 50.0e-6;  // for pre-emphisis filter.  50us time constant
        int clocksPerSample = 22500.0/samplerate*1400.0;  // for timing
        
        datanew = (float)(data)/32767;
        
        float sample = datanew   (dataold-datanew) / (1-fmconstant);  // fir of 1   s tau
        float dval = sample*15.0;  // actual transmitted sample.  15 is bandwidth (about 75 kHz)
        
        int intval = (int)(round(dval));  // integer component
        float frac = (dval - (float)intval)/2   0.5;
        unsigned int fracval = frac*clocksPerSample;
         
        bufPtr  ;
        while( ACCESS(DMABASE   0x04 /* CurBlock*/) ==  (int)(instrs[bufPtr].p)) usleep(1000);
        ((struct CB*)(instrs[bufPtr].v))->SOURCE_AD = (int)constPage.p   2048   intval*4 - 4 ;
        
        bufPtr  ;
        while( ACCESS(DMABASE   0x04 /* CurBlock*/) ==  (int)(instrs[bufPtr].p)) usleep(1000);
        ((struct CB*)(instrs[bufPtr].v))->TXFR_LEN = clocksPerSample-fracval;
        
        bufPtr  ;
        while( ACCESS(DMABASE   0x04 /* CurBlock*/) ==  (int)(instrs[bufPtr].p)) usleep(1000);
        ((struct CB*)(instrs[bufPtr].v))->SOURCE_AD = (int)constPage.p   2048   intval*4 4;
        
        bufPtr=(bufPtr 1) % (1024);
        while( ACCESS(DMABASE   0x04 /* CurBlock*/) ==  (int)(instrs[bufPtr].p)) usleep(1000);
        ((struct CB*)(instrs[bufPtr].v))->TXFR_LEN = fracval;
        
        dataold = datanew;
    }
    close(fp);
}

void unSetupDMA(){
    printf("exitingn");
    struct DMAregs* DMA0 = (struct DMAregs*)&(ACCESS(DMABASE));
    DMA0->CS =1<<31;  // reset dma controller
    
}

void handSig() {
    exit(0);
}
void setupDMA( float centerFreq ){

  atexit(unSetupDMA);
  signal (SIGINT, handSig);
  signal (SIGTERM, handSig);
  signal (SIGHUP, handSig);
  signal (SIGQUIT, handSig);

   // allocate a few pages of ram
   getRealMemPage(&constPage.v, &constPage.p);
   
   int centerFreqDivider = (int)((500.0 / centerFreq) * (float)(1<<12)   0.5);
   
   // make data page contents - it's essientially 1024 different commands for the
   // DMA controller to send to the clock module at the correct time.
   for (int i=0; i<1024; i  )
     ((int*)(constPage.v))[i] = (0x5a << 24)   centerFreqDivider - 512   i;
   
   
   int instrCnt = 0;
   
   while (instrCnt<1024) {
     getRealMemPage(&instrPage.v, &instrPage.p);
     
     // make copy instructions
     struct CB* instr0= (struct CB*)instrPage.v;
     
     for (int i=0; i<4096/sizeof(struct CB); i  ) {
       instrs[instrCnt].v = (void*)((int)instrPage.v   sizeof(struct CB)*i);
       instrs[instrCnt].p = (void*)((int)instrPage.p   sizeof(struct CB)*i);
       instr0->SOURCE_AD = (unsigned int)constPage.p 2048;
       instr0->DEST_AD = PWMBASE 0x18 /* FIF1 */;
       instr0->TXFR_LEN = 4;
       instr0->STRIDE = 0;
       //instr0->NEXTCONBK = (int)instrPage.p   sizeof(struct CB)*(i 1);
       instr0->TI = (1/* DREQ  */<<6) | (5 /* PWM */<<16) |  (1<<26/* no wide*/) ;
       instr0->RES1 = 0;
       instr0->RES2 = 0;
       
       if (i%2) {
         instr0->DEST_AD = CM_GP0DIV;
         instr0->STRIDE = 4;
         instr0->TI = (1<<26/* no wide*/) ;
       }
       
       if (instrCnt!=0) ((struct CB*)(instrs[instrCnt-1].v))->NEXTCONBK = (int)instrs[instrCnt].p;
       instr0  ;
       instrCnt  ;
     }
   }
   ((struct CB*)(instrs[1023].v))->NEXTCONBK = (int)instrs[0].p;
   
   // set up a clock for the PWM
   ACCESS(CLKBASE   40*4 /*PWMCLK_CNTL*/) = 0x5A000026;
   usleep(1000);
   ACCESS(CLKBASE   41*4 /*PWMCLK_DIV*/)  = 0x5A002800;
   ACCESS(CLKBASE   40*4 /*PWMCLK_CNTL*/) = 0x5A000016;
   usleep(1000); 

   // set up pwm
   ACCESS(PWMBASE   0x0 /* CTRL*/) = 0;
   usleep(1000);
   ACCESS(PWMBASE   0x4 /* status*/) = -1;  // clear errors
   usleep(1000);
   ACCESS(PWMBASE   0x0 /* CTRL*/) = -1; //(1<<13 /* Use fifo */) | (1<<10 /* repeat */) | (1<<9 /* serializer */) | (1<<8 /* enable ch */) ;
   usleep(1000);
   ACCESS(PWMBASE   0x8 /* DMAC*/) = (1<<31 /* DMA enable */) | 0x0707;
   
   //activate dma
   struct DMAregs* DMA0 = (struct DMAregs*)&(ACCESS(DMABASE));
   DMA0->CS =1<<31;  // reset
   DMA0->CONBLK_AD=0; 
   DMA0->TI=0; 
   DMA0->CONBLK_AD = (unsigned int)(instrPage.p);
   DMA0->CS =(1<<0)|(255 <<16);  // enable bit = 0, clear end flag = 1, prio=19-16
}



int main(int argc, char **argv)
{
    
    if (argc>1) {
      setup_fm();
      setupDMA(argc>2?atof(argv[2]):103.3);
      playWav(argv[1], argc>3?atof(argv[3]):22500);
    } else
      fprintf(stderr, "Usage:   program wavfile.wav [freq] [sample rate]nnWhere wavfile is 16 bit 22.5kHz Mono.  Set wavfile to '-' to use stdin.nfreq is in Mhz (default 103.3)nsample rate of wav file in HznnPlay an empty file to transmit silencen");
    
    return 0;

} // main

简简单单的目录,核心c代码.有空研究

这....没下载下来?

bash指令 bash apt-get http 网站

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