知识库
玩客云 UBoot 备份
#跳过 MBR 分区表，备份玩客云 UBoot 内容并压缩
-dc Boot_SkipUSBBurning.gz | dd of = /dev/mmcblk1 bs = 512 seek = 1 count = 32767
#恢复备份的 UBoot 内容
if = /dev/mmcblk1 bs = 512 skip = 1 count = 32767 | gzip > Boot_SkipUSBBurning.gz
玩客云 GPIO 驱动
实际上，从 Linux 4.8 开始，不再推荐使用 sysfs 接口（/sys/class/gpio）操作 GPIO，而是建议在用户空间使用字符设备进行操作，libgpiod 就是一个用于操作 GPIO 字符设备的库，同时提供了一些工具，方便开发者进行调试。libgpiod 包含一系列命令，有 gpioget、 gpioset、gpiodetect、gpioinfo、gpiofind 和 gpiomon 命令。
这里展示 sysfs 接口和 libgpiod 包命令两种方式操控玩客云 GPIO 的使用示例。
参考资料：gpioset 命令 | 人人都懂物联网 (getiot.tech)
玩客云 5.x Linux 内核的所有 GPIO 引脚
HDMI环出
#设置显示背景图片
text.png -T 1 -d /dev/fb0
#tty清屏
echo -e "\033c" > /dev/tty1
#隐藏光标
echo -e "\033[?25l" > /dev/tty1
#在HDMI显示器输出采集卡画面
--sink= kvmd::ustreamer::jpeg --output - | ffmpeg -use_wallclock_as_timestamps 1 -i pipe:c:v -an -pix_fmt bgr24 -f fbdev /dev/fb0
USB HID 继电器
CUS_HID USB 继电器的控制代码。
代码内容
C Python3
#include <linux/types.h>
#include <linux/input.h>
#include <linux/hidraw.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <fcntl.h>
#include <errno.h>
int find_usbrelay ()
{
int found = 0 ;
int fd = -1 ;
int result ;
int id ;
char path [ 32 ];
const struct hidraw_devinfo usb_relay_info =
{
. bustype = BUS_USB ,
. vendor = 0x5131 ,
. product = 0x2007
};
struct hidraw_devinfo t_info ;
for ( id = 0 ; ! found ; id ++ )
{
sprintf ( path , "/dev/hidraw%d" , id );
fd = open ( path , O_RDWR | O_NONBLOCK );
if ( fd < 0 )
break ;
result = ioctl ( fd , HIDIOCGRAWINFO , & t_info );
if ( result < 0 )
break ;
if (( t_info . bustype == usb_relay_info . bustype )
&& ( t_info . vendor == usb_relay_info . vendor )
&& ( t_info . product = usb_relay_info . product ))
{
found = 1 ;
break ;
}
close ( fd );
fd = -1 ;
}
if ( fd >= 0 )
close ( fd );
return found ? id : -1 ;
}
int set_usbrelay_onoff ( int id , int ch , int onoff )
{
int fd = -1 ;
uint8_t cmd [ 8 ];
char path [ 32 ];
do
{
sprintf ( path , "/dev/hidraw%d" , id );
fd = open ( path , O_RDWR | O_NONBLOCK );
if ( fd < 0 )
break ;
cmd [ 0 ] = 0xA0 ;
cmd [ 1 ] = ch ; // 1, 2
cmd [ 2 ] = onoff ; // 0, 1
cmd [ 3 ] = cmd [ 0 ] + cmd [ 1 ] + cmd [ 2 ];
write ( fd , cmd , 4 );
} while ( 0 );
if ( fd >= 0 )
close ( fd );
return 0 ;
}
int main ( int argc , char * argv [])
{
int result ;
int id ;
int ch ;
int onoff ;
char path [ 32 ];
do
{
if ( argc != 3 )
{
printf ( "Usage: \n "
" \t usbrelay ch on|off \n " );
break ;
}
ch = atoi ( argv [ 1 ]);
if ( strcmp ( argv [ 2 ], "on" ) == 0 )
onoff = 1 ;
else if ( strcmp ( argv [ 2 ], "off" ) == 0 )
onoff = 0 ;
else
break ;
id = find_usbrelay ();
if ( id < 0 )
{
printf ( "usbrelay not found \n " );
break ;
}
set_usbrelay_onoff ( id , ch , onoff );
} while ( 0 );
return 0 ;
}
import sys
import hid
VENDOR_ID = 0x5131
PRODUCT_ID = 0x2007
def find_usbrelay ():
for device in hid . enumerate ():
if device . get ( "vendor_id" ) == VENDOR_ID and device . get ( "product_id" ) == PRODUCT_ID :
return device
return None
def send_command ( device_info , channel , onoff ):
device = hid . device ()
device . open ( device_info [ 'vendor_id' ], device_info [ 'product_id' ])
if device is None :
print ( "Failed to open device." )
return
try :
cmd = [ 0xA0 , channel , onoff , 0xA0 + channel + onoff ]
device . write ( bytearray ( cmd ))
finally :
device . close ()
def main ():
if len ( sys . argv ) != 3 :
print ( "Usage: \n "
" \t python script.py id on|off" )
return
try :
id = int ( sys . argv [ 1 ])
if sys . argv [ 2 ] . lower () == 'on' :
onoff = 1
elif sys . argv [ 2 ] . lower () == 'off' :
onoff = 0
else :
raise ValueError
except ValueError :
print ( "Invalid command, use 'on' or 'off'" )
return
device_info = find_usbrelay ()
if device_info is None :
print ( "USB relay not found" )
else :
send_command ( device_info , id , onoff )
print ( f "Sent command to channel { id } : { 'ON' if onoff else 'OFF' } " )
if __name__ == "__main__" :
main ()
参考资料：
在 Linux 中重置 USB 设备
如果如 USB 设备处于异常状态，可以使用 usbreset 实用程序重置它。可以使用以下适合特定 Linux 发行版的命令来安装 usbreset。
apt install usbutils [ On Debian, Ubuntu and Mint]
yum install usbutils [ On RHEL/CentOS/Fedora and Rocky/AlmaLinux]
emerge -a sys-apps/usbutils [ On Gentoo Linux]
apk add usbutils [ On Alpine Linux]
pacman -S usbutils [ On Arch Linux]
zypper install usbutils [ On OpenSUSE]
pkg install usbutils [ On FreeBSD]
安装后，可以使用以下命令重置 USB 设备，将 Bus 001 Device 004 替换为 USB 设备的总线和设备号：
usbreset /dev/bus/usb/001/004
或者，可以使用以下命令，其中 是 USB 设备的 ID（来自 lsusb 输出）：
usbreset 090c:1000
usbreset 001 :005
参考资料：