我用C#写了个上位机，经测试串口是有用的，但是连到短信猫上就不行了，短信猫一直没回信，但是短信猫用 超级终端测试完全正确
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;

namespace Uart
{
public partial class Uart : Form
{
public Uart()
{
InitializeComponent();
}
//声明串口
public SerialPort sp = new SerialPort();
//定义委托
delegate void HandleInterfaceUpdateDelegate(string text);
//实例化委托
HandleInterfaceUpdateDelegate interfaceUpdateHandle = null;
//开始初始化
private void Uart_Load(object sender, EventArgs e)
{
this.label_Uart_Info.Text = "";
//初始化tabcontrol
this.tabControl1.SelectedIndex = 1;
//initialize combobox_enter
this.cbxTransfer.SelectedIndex = 0;
interfaceUpdateHandle = new HandleInterfaceUpdateDelegate(Updata_Text_Rec);
}
private void Updata_Text_Rec(string text)
{
richTextBox_Rec.Text += text;
}
public int sendCount = 0;
public int recCount = 0;
//打开串口
private void btn_Link_Uart_Click(object sender, EventArgs e)
{
sp.PortName = "COM3";
sp.BaudRate = 9600;
sp.DataBits = 8;
sp.Parity = Parity.None;
sp.StopBits = StopBits.One;
sp.ReceivedBytesThreshold = 1;
sp.Encoding = Encoding.GetEncoding("utf-8");
try
{
sp.Open();
}
catch (System.IO.IOException ex)
{
MessageBox.Show(ex.ToString());
}
sp.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(this.sp_DataReceive);
label_Uart_Info.Text = sp.PortName + ',' + sp.BaudRate + ',' + sp.DataBits + ',' + sp.Parity + ',' + sp.StopBits;
if (sp.IsOpen == true)
{
MessageBox.Show("串口连接成功");
}
else
{
MessageBox.Show("串口连接失败");
}
}
//关闭串口
private void btn_Break_Uart_Click(object sender, EventArgs e)
{
sp.Close();
richTextBox_Rec.Text = "";
richTextBox_Send.Text = "";
label_Uart_Info.Text = "未连接";
if (sp.IsOpen == false)
{
MessageBox.Show("串口正常关闭");
this.lbSendCount.Text = "发送计数";
this.lbRecCount.Text = "接收计数";
}
else
{
MessageBox.Show("串口未能关闭");
}
}
//DataReceived事件委托方法
private void sp_DataReceive(object sender, EventArgs e)
{
byte[] databuf = new byte[sp.BytesToRead];
sp.Read(databuf, 0, sp.BytesToRead);
this.recCount += databuf.Length;
//this.lbRecCount.Text = string.Format("接收到{0:X}Byte", this.recCount);

if (this.checkHex.Checked == true)
{
string readbuf = null;
//十六进制格式化数据
for (int i = 0; i < databuf.Length; i++)
{
string s = String.Format("{0:X}", Convert.ToInt32(databuf[i]));
if (s.Length > 1)
{
readbuf += s + " ";
}
else
{
readbuf += "0" + s + " ";
}
}
this.Invoke(interfaceUpdateHandle, readbuf);
}
else
{
this.Invoke(interfaceUpdateHandle, Encoding.UTF8.GetString(databuf));
}
}
//断开连接

private void textBox_Send_Period_TextChanged(object sender, EventArgs e)
{
if (textBox_Send_Period.Text == null || textBox_Send_Period.Text == "")
{
timer_Uart_Send.Interval = 1000;
}
else
{
timer_Uart_Send.Interval = Convert.ToInt32(textBox_Send_Period.Text);
}
}

private void timer_Uart_Send_Tick(object sender, EventArgs e)
{
if (cbxAutoSend.Checked == true)
{
if (sp.IsOpen == true)
{
sp.Write(richTextBox_Send.Text);
}
else
{
MessageBox.Show("串口未打开");
}
}
}

private void btnSendByHand_Click(object sender, EventArgs e)
{
if (cbxAutoSend.Checked == false)
{
sp.Write(richTextBox_Send.Text);
}
}

private void Uart_FormClosing(object sender, FormClosingEventArgs e)
{
if (sp.IsOpen == true)
{
sp.Close();
}
}
//发送数据
private void richTextBox_Send_TextChanged(object sender, EventArgs e)
{
if (richTextBox_Send.Text != "")
{
string str = richTextBox_Send.Text;
str = str.Substring(str.Length - 1, 1);
sendCount += str.Length;
lbSendCount.Text = string.Format("发送{0:D}Byte", sendCount);
if (sp.IsOpen == true)
{
if(str.Equals("\n"))
{
if(cbxTransfer.SelectedItem.ToString().Equals("CR"))
sp.Write("\r");
else if(cbxTransfer.SelectedItem.ToString().Equals("CR+LF"))
sp.Write("\r\n");
else if(cbxTransfer.SelectedItem.ToString().Equals("LF"))
sp.Write("\n");
else
sp.Write("\r");
}
else

{
sp.Write(str);
}
}
}
}

private void button1_Click(object sender, EventArgs e)
{
sp.Write("AT\r");
sendCount += ("AT\r").Length;
lbSendCount.Text = string.Format("发送{0:D}Byte", sendCount);
}
}
}


[解决办法]
连接短信猫后，有没有用串口调试助手监视收发的数据。看数据在这种情况下是否能发送和接收。如果发不出，接不到，检查一下发送的数据格式是否正确。
[解决办法]
短信猫不要采用二进制方式发送和接收数据，就是文本方式
连接好以后，先发送一些“AT\r”，看看返回是不是OK
[解决办法]
1) 单 发 英文 可以吗？
2） 你的短信毛支持直接发送中文码
3）发中文 的话如果不用第三方 lib 的好像要用到 PDU

同 13 楼


[解决办法]
估计是楼主的编码写错了~先看看AT指令再写短信猫的程序吧，之前的我也有碰到过这个问题，是我的AT指令写的有问题，楼主好好检查下吧~看看是不是指令的问题