Question

我将PIC 16F887A连接到串行端口。我希望它在接收到0x01时点亮一个绿色LED，当它从pc接收到0x00时点亮一个红色LED。我从C＃windows窗体应用程序发送字符，PIC本身用CCS C编程。你可以告诉我我做错了什么，因为下面的代码不起作用？

编辑：通过不起作用我的意思是它在两种情况下都会失去红色。

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.Windows.Forms;
using System.IO;
using System.IO.Ports;

namespace deneme
{
    public partial class Form1 : Form
    {
        SerialPort port = new SerialPort("COM2", 9600, Parity.None, 8, StopBits.One);
        public Form1()
        {
            InitializeComponent();
        }

        private void openportbtn_Click(object sender, EventArgs e)
        {
            if (port.IsOpen)
            {
                port.Close();
            }

            if (!port.IsOpen)
            {
                port.Open();
            }
        }

        private void rightbtn_Click(object sender, EventArgs e)
        {
            byte[] right = new byte[1];
            right[0] = 0x01;
            port.Write(right, 0, right.Length);
        }

        private void wrongbtn_Click(object sender, EventArgs e)
        {
            byte[] wrong = new byte[1];
            wrong[0] = 0x00;
            port.Write(wrong, 0, wrong.Length);
        }
    }
}

CCS C代码

#include <16f877A.h>

#fuses XT,NOWDT,NOPROTECT,NOBROWNOUT,NOLVP,NOPUT,NOWRT,NODEBUG,NOCPD

#use delay (clock=4000000)

#use rs232 (baud=9600, xmit=pin_c6, rcv=pin_c7, parity=N, stop=1, bits=8)

char received;
char right = 0x01;

#int_rda
void serial_interrupt()
{
   disable_interrupts(int_rda);
   received = getc();
   if(received == right)
   {
      output_high(pin_c5); //green led
      delay_ms(200);
      output_low(pin_c5);
   }
   else
   {
      output_high(pin_c4); //red led
      delay_ms(200);
      output_low(pin_c4);
   }
}

void main()
{
   setup_psp(PSP_DISABLED);
   setup_timer_1(T1_DISABLED);
   setup_timer_2(T2_DISABLED,0,1);
   setup_adc_ports(NO_ANALOGS);
   setup_adc(ADC_OFF);
   setup_CCP1(CCP_OFF);
   setup_CCP2(CCP_OFF);

   output_low(pin_c4);
   output_low(pin_c5);

   enable_interrupts(GLOBAL);
   while(1)
   {
      enable_interrupts(int_rda);
   }
}

Answer 1

如果在两种情况下都接收到0x00，则可能是波特率不匹配，即使是轻微的波特率。检测到起始位后，PIC可能会看到前7个零，并认为它看到8，在这两种情况下都是0x00。我会尝试从PIC和PC进行传输并观察示波器上的线路以确保它们以相同的速度运行。您也可以尝试连续发送0xAA以获得眼图（10101010）并比较这两个信号。

C＃串行端口+ CCS C串行端口+ PIC 16F877A

1 个答案: