modem_control
时间: 2023-09-18 13:08:48 浏览: 54
您好!对于 modem_control,这是一个用于控制调制解调器的功能或接口。调制解调器(modem)是一种设备,它将数字信号转换为模拟信号以便在通信线路上传输,同时也可以将接收到的模拟信号转换回数字信号。
modem_control 可能是指控制调制解调器的一些操作,比如设置连接参数、发送和接收数据等。通常,操作调制解调器需要使用特定的命令或协议,这些命令可以通过串行端口(如RS-232)或网络接口(如TCP/IP)发送给调制解调器进行控制。
请问您对 modem_control 有具体的问题或需求吗?我将竭尽所能提供帮助。
相关问题
我有一个安卓ppp脚本,如何让它在开机时自动调用:# /etc/ppp/peers/quectel-pppd # Usage:root>pppd call quectel-pppd #Modem path, like /dev/ttyUSB3,/dev/ttyACM0, depend on your module, default path is /dev/ttyUSB3 /dev/ttyUSB3 115200 #Insert the username and password for authentication, default user and password are test user "test" password "test" # The chat script, customize your APN in this file connect 'chat -s -v -f /etc/ppp/peers/quectel-chat-connect' # The close script disconnect 'chat -s -v -f /etc/ppp/peers/quectel-chat-disconnect' # Hide password in debug messages hide-password # The phone is not required to authenticate noauth # Debug info from pppd debug # If you want to use the HSDPA link as your gateway defaultroute # pppd must not propose any IP address to the peer noipdefault # No ppp compression novj novjccomp noccp ipcp-accept-local ipcp-accept-remote local # For sanity, keep a lock on the serial line modem dump nodetach # Hardware flow control nocrtscts remotename 3gppp ipparam 3gppp ipcp-max-failure 30 # Ask the peer for up to 2 DNS server addresses usepeerdns并且在脚本中添加下面这一操作:
你可以将这个脚本放在 /etc/init.d/ 目录下,并添加启动脚本来确保它在开机时被调用。具体步骤如下:
1. 将脚本复制到 /etc/ppp/peers/quectel-pppd 中。
2. 创建一个启动脚本 /etc/init.d/quectel-pppd,内容如下:
```
#!/bin/sh
# chkconfig: 2345 99 01
# description: auto start quectel-pppd
case "$1" in
start)
echo "Starting quectel-pppd..."
/usr/sbin/pppd call quectel-pppd
;;
stop)
echo "Stopping quectel-pppd..."
killall pppd
;;
restart)
$0 stop
sleep 1
$0 start
;;
*)
echo "Usage: $0 {start|stop|restart}"
;;
esac
exit 0
```
3. 添加执行权限:
```
chmod +x /etc/init.d/quectel-pppd
```
4. 将脚本添加到启动项中:
```
update-rc.d quectel-pppd defaults
```
这样,在下一次重启后,quectel-pppd 脚本将会自动被调用。
设计一个基于S3C2410的简单应用系统带有一个4x4键盘,各个按键对应编号为:0、1、2、3、4、5、6、7、8、9、A、B、C、D、E、F,某个键摁下时通过RS232口将对应的ASCII码发送出去的C语言程序
由于没有具体的硬件原型和操作系统,下面给出的是一个基于S3C2410的简单应用系统的伪码,供参考:
```c
// 定义键盘按键编号
#define KEY_0 0
#define KEY_1 1
#define KEY_2 2
#define KEY_3 3
#define KEY_4 4
#define KEY_5 5
#define KEY_6 6
#define KEY_7 7
#define KEY_8 8
#define KEY_9 9
#define KEY_A 10
#define KEY_B 11
#define KEY_C 12
#define KEY_D 13
#define KEY_E 14
#define KEY_F 15
// 定义RS232串口通信相关寄存器
#define UART_BASE_ADDR 0x50000000 // RS232串口基地址
#define ULCON0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x0000)) // UART Line Control Register 0
#define UCON0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x0004)) // UART Control Register 0
#define UFCON0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x0008)) // UART FIFO Control Register 0
#define UMCON0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x000C)) // UART Modem Control Register 0
#define UBRDIV0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x0028)) // UART Baud Rate Divisor Register 0
#define UTXH0 (*(volatile unsigned int *)(UART_BASE_ADDR + 0x002C)) // UART Transmit Buffer Register 0
void init_uart() {
// 设置RS232串口通信相关寄存器
ULCON0 = 0x3;
UCON0 = 0x5;
UFCON0 = 0x0;
UMCON0 = 0x0;
UBRDIV0 = 26; // 波特率为115200,时钟频率为50MHz,UBRDIV0 = (时钟频率 / (波特率 * 16)) - 1
}
int main() {
init_uart();
while (1) {
// 读取键盘状态并发送对应的ASCII码
if (KEY_0 is pressed) {
UTXH0 = '0';
}
if (KEY_1 is pressed) {
UTXH0 = '1';
}
if (KEY_2 is pressed) {
UTXH0 = '2';
}
if (KEY_3 is pressed) {
UTXH0 = '3';
}
if (KEY_4 is pressed) {
UTXH0 = '4';
}
if (KEY_5 is pressed) {
UTXH0 = '5';
}
if (KEY_6 is pressed) {
UTXH0 = '6';
}
if (KEY_7 is pressed) {
UTXH0 = '7';
}
if (KEY_8 is pressed) {
UTXH0 = '8';
}
if (KEY_9 is pressed) {
UTXH0 = '9';
}
if (KEY_A is pressed) {
UTXH0 = 'A';
}
if (KEY_B is pressed) {
UTXH0 = 'B';
}
if (KEY_C is pressed) {
UTXH0 = 'C';
}
if (KEY_D is pressed) {
UTXH0 = 'D';
}
if (KEY_E is pressed) {
UTXH0 = 'E';
}
if (KEY_F is pressed) {
UTXH0 = 'F';
}
}
return 0;
}
```
实际上,该程序只是简单地读取键盘状态并发送对应的ASCII码,可以根据具体需求进行修改。另外,需要注意的是,该程序并没有进行任何错误处理和边界检查,实际使用时需要加入相应的处理。
相关推荐
![gz](https://img-home.csdnimg.cn/images/20210720083447.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![application/x-rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![application/msword](https://img-home.csdnimg.cn/images/20210720083327.png)
![application/x-rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![rar](https://img-home.csdnimg.cn/images/20210720083606.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)