gsm与LPC2148的接口

Question

我正试图从我的ARM7 LPC2148板发送消息。我已经将SIM900 GSM调制解调器连接到板的UART0。但我的手机没有收到消息！！我把打印报表放在这里和那里，这样我就知道系统在哪里，它在哪里卡住了。但它会打印所有的信息。上面写着尽管我并没有收到任何短信，但还是发送了信息。这是代码：

主代码

#include "i2c.h"                      
#include "LPC214x.H"                                    // LPC2148 MPU Register
#include <stdio.h>
#include "gsm.h"
#include "lcd.h"
#include "buzzer.h"

extern int msgflag;                                                     
/* Main Program Start Here */
int main(void)
{  
PINSEL0 = 0x00000000;        // Enable GPIO on all pins
PINSEL1 = 0x00000000;
PINSEL2 = 0x00000000;

lcd_init();                                           // Initial LCD
lcd_write_control(0x01);                              // Clear Display  (Clear Display,Set DD RAM Address=0) 
goto_cursor(0x00);                                  // Set Cursor Line-1
lcd_print("Accident Alert");                        // Display LCD Line-1  
// Display LCD Line-2
// Display Delay
// Clear Display  (Clear Display,Set DD RAM Address=0) 
// Display LCD Line-1    
goto_cursor(0x40);                                  // Set Cursor = Line-2
lcd_print("System");                        // Display LCD Line-2
delay1(100000000);

gsmperform();
// Loop Print Message to LCD16 x 2 //
// Loop Continue




sendmsg();
msgflag=0;
lcd_write_control(0x01);                            // Clear Display  (Clear Display,Set DD RAM Address=0) 
goto_cursor(0x00);                                  // Set Cursor Line-1
lcd_print("Message sent");                      // Display LCD Line-1  

}

gsm.c

#include<lpc214x.h>                                                  /*Header file*/
#include "gsm.h"                
#include "lcd.h"                                     //header file
extern unsigned char cmgf[]="AT+CMGF=1";                            //Text format in GSM modem
extern unsigned char cmgs[]="AT+CMGS="9xxxxxxxxx"";               //Mobile number to which the msg is sent
extern unsigned char msg[]="hello";                                //secret code
extern unsigned char readall[]="AT+CMGR="REC UNREAD"rn";

extern int blink;
unsigned char content[7];
void txu1(unsigned char data)                 //Transmit a byte of data through UART1
{
while(!(U1LSR & 0x20));                         // Wait until UART1 ready to send character  
U1THR = data; 
}
unsigned char rxu1()
{
unsigned char p;
while ((U1LSR&0x01)!=1);
p=U1RBR;
return p;
}
unsigned char rxu0()
{
unsigned char p;
while ((U0LSR&0x01)!=1);
p=U0RBR;
return p;
}
void sendstring(unsigned char *p)            //Sends a string of data through UART1
{
while(1)
{
if(*p=='') break;
txu1(*p++);
}
}
void delaygsm()                           //delay function
{
int i,j;
for(i=0;i<60000;i++)
for(j=0;j<51;j++);
}
void delay2()                             //delay function
{
int i,j;
for(i=0;i<60000;i++)
for(j=0;j<200;j++);
}
unsigned char recuart1()             //recieves a byte from UART1
{
unsigned char p;
while ((U1LSR&0x01)!=1);
p=U1RBR;
return p;
}


void uart1_irq() __irq                    //ISR if anything is recieved in UART1, the same is transmitted through UART0
{
unsigned char p;
p=U1RBR;
if(p=='a')
{
sendmsg();
}
VICVectAddr=0;
}
void sendmsg(void)
{

sendstring(msg);

}
void initgsm()                               //Initialization of UART0,UART1 and ISR
{
U0LCR=0x83;
U0DLL=0x61;
U0DLM=0x00;
U0LCR=0x03;
U1LCR=0x83;
U1DLL=0x61;
U1DLM=0x00;
U1LCR=0x03;
U1IER=0x01;
U1FCR=0x07;
VICIntSelect&=0xffffff7f;
VICVectAddr2=(unsigned int)uart1_irq;
VICIntEnable|=0x00000080;
VICVectCntl2=0x20|7;  
}
void gsmperform(void)
{
lcd_write_control(0x01);                            // Clear Display  (Clear Display,Set DD RAM Address=0) 
goto_cursor(0x00);                                  // Set Cursor Line-1
lcd_print("begin gsm");                     // Display LCD Line-1  
PINSEL0|=0x00050005;
PINSEL1|=0x00000000;
PINSEL2|=0x00000000;
initgsm();
sendstring("ATe0rn");
delaygsm();
sendstring("AT+CMGD=1,4rn");
delaygsm();
sendstring("AT+CNMI=1,0,0,0rn");
delaygsm();
lcd_write_control(0x01);                            // Clear Display  (Clear Display,Set DD RAM Address=0) 
goto_cursor(0x00);                                  // Set Cursor Line-1
lcd_print("end gsm");                       // Display LCD Line-1  
}

Answer 1

将问题分解为三个部分-配置&发送命令，接收正确的命令，并协同工作。

1. 将LPC2148板连接到PC，并使用PC终端程序查看您发送的命令。确保程序的各个部分工作正常。您是否在编译器中运行任何优化选项？这肯定会打乱你的延迟功能。使用内置计时器来提供延迟，而不是for循环
2. 确保使用正确的命令与GSM卡通话。如果可能，请将其连接到PC(如果没有RS-232收发器，请确保将逻辑电平转换为UART电平)，或连接到运行交互式终端的套件。确保您的命令确实会发送一条带有您选择的模块的短信
3. 现在连接套件和模块。到目前为止，您应该知道哪些信号实际上是输出，哪些是输入——RS-232可能会对此感到非常困惑。大多数处理器UART被标记为DTE(TX==输出，RX==输入)，我希望通信模块被标记为DCE(TX===输入，RX===输出)，这意味着你将连接RX<->RX和TX<->TX。如果它们都被标记为DTE，那么您需要一根零调制解调器电缆来交换信号，或者在连接板时手动进行