**
我需要一些帮助。
我为我的arm处理器编写了一个程序，通过UART（USB）发送字符'a'。频率为1个字符/秒。 所以，我在Visual C＃中编写了一个程序来接收这个角色并在文本框中显示。只是一个非常简单的程序。
串行通信的配置正常（baud_rate，stopbit，parity，data_bits）
问题：我无法读取手臂处理器发送的字符。
事实：
1 - arm程序在Putty中正常工作。
2 - 我的visual c＃程序与arduino板正常工作，它具有与arm相同的代码。
请大家看看我的代码，如果可以，请帮助我。
这是ARM的代码：
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/interrupt.h"
#include "driverlib/sysctl.h"
#include "driverlib/uart.h"
#include "drivers/rit128x96x4.h"
//*****************************************************************************
//
//! \addtogroup example_list
//! <h1>UART Echo (uart_echo)</h1>
//!
//! This example application utilizes the UART to echo text. The first UART
//! (connected to the FTDI virtual serial port on the evaluation board) will be
//! configured in 115,200 baud, 8-n-1 mode. All characters received on the
//! UART are transmitted back to the UART.
//
//*****************************************************************************
//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, unsigned long ulLine)
{
}
#endif
//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{
unsigned long ulStatus;
//
// Get the interrrupt status.
//
ulStatus = UARTIntStatus(UART0_BASE, true);
//
// Clear the asserted interrupts.
//
UARTIntClear(UART0_BASE, ulStatus);
//
// Loop while there are characters in the receive FIFO.
//
while(UARTCharsAvail(UART0_BASE))
{
//
// Read the next character from the UART and write it back to the UART.
//
//UARTCharPutNonBlocking(UART0_BASE, UARTCharGetNonBlocking(UART0_BASE));
UARTCharPutNonBlocking(UART0_BASE,'a');
SysCtlDelay(16666666); //1.2 ms
}
}
//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const unsigned char *pucBuffer, unsigned long ulCount)
{
//
// Loop while there are more characters to send.
//
while(ulCount--)
{
//
// Write the next character to the UART.
//
UARTCharPutNonBlocking(UART0_BASE, *pucBuffer++);
}
}
//*****************************************************************************
//
// This example demonstrates how to send a string of data to the UART.
//
//*****************************************************************************
int
main(void)
{
//
// Set the clocking to run directly from the crystal.
//
//SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN | SYSCTL_XTAL_8MHZ);
SysCtlClockSet(SYSCTL_SYSDIV_4 | SYSCTL_USE_PLL | SYSCTL_OSC_MAIN | SYSCTL_XTAL_8MHZ);
//
// Initialize the OLED display and write status.
//
RIT128x96x4Init(1000000);
RIT128x96x4StringDraw("UART Echo", 36, 0, 15);
RIT128x96x4StringDraw("Port: Uart 0", 12, 16, 15);
RIT128x96x4StringDraw("Baud: 115,200 bps", 12, 24, 15);
RIT128x96x4StringDraw("Data: 8 Bit", 12, 32, 15);
RIT128x96x4StringDraw("Parity: None", 12, 40, 15);
RIT128x96x4StringDraw("Stop: 1 Bit", 12, 48, 15);
//
// Enable the peripherals used by this example.
//
SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);
//
// Enable processor interrupts.
//
IntMasterEnable();
//
// Set GPIO A0 and A1 as UART pins.
//
GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0 | GPIO_PIN_1);
//
// Configure the UART for 115,200, 8-N-1 operation.
//
UARTConfigSetExpClk(UART0_BASE, SysCtlClockGet(), 9600,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));
//
// Enable the UART interrupt.
//
IntEnable(INT_UART0);
UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);
UARTFIFOEnable(UART0_BASE);
UARTEnable(UART0_BASE);
//
// Prompt for text to be entered.
//
UARTSend((unsigned char *)"Enter text: ", 12);
//
// Loop forever echoing data through the UART.
//
while(1)
{
}
}
这是Visual C＃代码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO.Ports;
namespace interfaceArduinoVS2013
{
public partial class Form1 : Form
{
string RxString;
public Form1()
{
InitializeComponent();
timerCOM.Enabled = true;
}
private void atualizaListaCOMs()
{
int i;
bool quantDiferente; //flag para sinalizar que a quantidade de portas mudou
i = 0;
quantDiferente = false;
//se a quantidade de portas mudou
if (comboBox1.Items.Count == SerialPort.GetPortNames().Length)
{
foreach (string s in SerialPort.GetPortNames())
{
if (comboBox1.Items[i++].Equals(s) == false)
{
quantDiferente = true;
}
}
}
else
{
quantDiferente = true;
}
//Se não foi detectado diferença
if (quantDiferente == false)
{
return; //retorna
}
//limpa comboBox
comboBox1.Items.Clear();
//adiciona todas as COM diponíveis na lista
foreach (string s in SerialPort.GetPortNames())
{
comboBox1.Items.Add(s);
}
//seleciona a primeira posição da lista
comboBox1.SelectedIndex = 0;
}
private void timerCOM_Tick(object sender, EventArgs e)
{
atualizaListaCOMs();
}
private void btConectar_Click(object sender, EventArgs e)
{
if (serialPort1.IsOpen == false)
{
try
{
serialPort1.PortName = comboBox1.Items[comboBox1.SelectedIndex].ToString();
serialPort1.Open();
}
catch
{
return;
}
if (serialPort1.IsOpen)
{
btConnect.Text = "Disconnect";
comboBox1.Enabled = false;
}
}
else
{
try
{
serialPort1.Close();
comboBox1.Enabled = true;
btConnect.Text = "Connect";
}
catch
{
return;
}
}
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
if(serialPort1.IsOpen == true) // if port opened
serialPort1.Close(); //close the port
}
private void btEnviar_Click(object sender, EventArgs e)
{
if(serialPort1.IsOpen == true)
serialPort1.Write(textBoxSend.Text); //send the text in the textbox
RxString = serialPort1.ReadExisting();
MessageBox.Show(RxString);
}
private void serialPort1_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
RxString = serialPort1.ReadExisting(); //read data from serial port
MessageBox.Show(RxString);
this.Invoke(new EventHandler(trataDadoRecebido)); //call another thread to write the data on textbox
}
private void trataDadoRecebido(object sender, EventArgs e)
{
textBoxReceive.AppendText(RxString);
}
}
}
答案 0 :(得分：1)
您很可能遇到波特率问题。在C＃代码中，我没有看到你设置COM端口的波特率的任何地方。如果在ARM板上打印时为115200，则问题出在ARM板本身。您打印115,200作为波特率，但您正在初始化ARM板9600 8N1
//
// Configure the UART for 115,200, 8-N-1 operation.
//
UARTConfigSetExpClk(UART0_BASE, SysCtlClockGet(), 9600,
(UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
UART_CONFIG_PAR_NONE));
在打开端口之前，先对通信线路的两端进行初始化，然后重试。通常，发送器上较小的波特率将导致高速配置的接收器上没有打印字符。另一方面，配置缓慢的接收器（9600）将从高速发射器捕获一些垃圾。