关于atmega32u4的CDC模拟串口程序

编程环境使用的是AVR studio

下载程序在这个链接里https://www.pjrc.com/teensy/usb_serial.html

关键是电脑要安装驱动才能正常通信

 1 include <avr/io.h>
 2 #include <avr/pgmspace.h>
 3 #include <stdint.h>
 4 #include <util/delay.h>
 5 #include <stdio.h>
 6 #include <string.h>
 7 #include "usb_serial.h"
 8 
 9 
10 #define LED_CONFIG    (DDRD |= (1<<6))
11 #define LED_ON        (PORTD |= (1<<6))
12 #define LED_OFF        (PORTD &= ~(1<<6))
13 #define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
14 
15 void send_str(const char *s);
16 
17 int main(void)
18 {
19     CPU_PRESCALE(0);
20     
21     LED_CONFIG;//输出拉低
22     LED_OFF;
23 
24     usb_init();
25 
26     while(1)
27     {
28         unsigned char buffer[3] = {0};
29         
30         int n = usb_serial_available();//获取缓存区中的字节数
31     
32         if(n>3 || (n<3 && n!=0))
33         {
34             send_str(PSTR(" please enter 3 words\n"));        
35             n = 0;
36             usb_serial_flush_input();
37         }
38         else
39         {
40             for(int i = 0;i<n;i++)
41             {
42                 int m = usb_serial_getchar();
43                 if(m>=0)
44                 {
45                     buffer[i] = m;
46                 }
47             }
48         }
49         if (buffer[0]== 0xAA && buffer[2] == 0x55)
50         {
51             switch(buffer[1])
52             {
53                 case 0x31:
54 
55                 //    DDRD |= (1<<6);//输出拉高
56                 //    LED_ON;
57                     send_str(PSTR(" OPEN RHP-260+\n"));
58                 break;
59 
60                 case 0x32:
61 
62                 //    DDRD |= (1<<6);//输出拉低
63                 //    LED_OFF;
64                     memset(buffer,0,3);
65                     send_str(PSTR(" OPEN RHP-700+\n"));
66                 break;
67             
68                 default:
69                     usb_serial_putchar(buffer[1]);
70                     send_str(PSTR(" wrong\n"));
71                     memset(buffer,0,3);
72                 break;
73             }
74         }
75     }
76 }
77 
78 // Send a string to the USB serial port.  The string must be in
79 // flash memory, using PSTR
80 //
81 void send_str(const char *s)
82 {
83     char c;
84     while (1) {
85         c = pgm_read_byte(s++);
86         if (!c) break;
87         usb_serial_putchar(c);
88     }
89 }