我正在尝试为AVR STK600板编写一个程序，其中我正在通过LED循环。按下开关时，相应的LED会亮起（到此为止，一切顺利）。现在我正在为电路板添加另一个功能，尝试使用USART（RS232串行通信）。
- 当用户按下某个键时，应该回显（在超级终端上）。 - 当击中crtl-Z时，数据应记录在EEPROM中（再次击中crtl-z应停止记录）。 - 按下crtl-y时，应播放录制的数据。
这里遇到的问题是USART（我确实检查了所有硬件设置，进行了环回测试......一切运行正常）所以代码应该有问题。在EEPROM，USART进展顺利之后，一切顺利。
这是我的代码，我正在使用AVR-GCC。我也没有使用“avrlib”，因为正在采取的课程不允许我们这样做：
#include "header.h"
#define BASE_ADDR 0x20
#define READ_ATMEGA(ADDR) *((P_CHAR)(BASE_ADDR + ((ADDR) * ADDR_MULTIPLIER)))
#define WRITE_ATMEGA(ADDR, DATA) *((P_CHAR)(BASE_ADDR + ((ADDR) * ADDR_MULTIPLIER))) = DATA
#define LED_DELAY 10
#define F_CPU 8000000
#define BAUDRATE 9600
#define BAUD_PRESCALER (((F_CPU/(BAUDRATE * 16UL)))-1)
volatile UINT intrs, i = 1, count, switch_pressed = 0, uiAdd, uiAddEnd, flag_led_intr;
volatile UINT record, play_recorded_keys, RX, flag_serial_receiver, TX_complete;
volatile unsigned char get_switch=0, data;
extern void __vector_23 (void) __attribute__ ((interrupt));
extern void __vector_25 (void) __attribute__ ((signal));
extern void __vector_27 (void) __attribute__ ((interrupt));
void enable_ports(void);
int get_switchpressed(void);
void call_interruptHandler(void);
void usart_init(void);
//void usart_bounce();
void initialize(void);
void ReadWriteSerialPort(void);
void EEPROM_write(unsigned int uiAddress, unsigned char ucData);
unsigned char EEPROM_read(unsigned int uiAddress);
void initialize(void)
{
cli(); //stop all interrupts
flag_led_intr = 0;
record = 0;
play_recorded_keys = 0;
RX = 0;
flag_serial_receiver = 0;
uiAdd = 0;
uiAddEnd = 0;
TX_complete = 0;
enable_ports();
usart_init();
sei();
}
void enable_ports() //Enables PORTB, PORTD & TIMER
{
WRITE_ATMEGA(DDRB,0xff); //PORTB as output for leds
WRITE_ATMEGA(PORTB,0xff); //Initialize PORTB
WRITE_ATMEGA(DDRD, 0x00); //PORTD as input for switches
WRITE_ATMEGA(TCCR0B, 0x05); //Setting TIMER to 1024 prescaler
WRITE_ATMEGA(TIMSK0, 0x01);
WRITE_ATMEGA(TCNT0, 256-LED_DELAY);
intrs = 0;
}
void usart_init(void) //Enables USART
{
/* Set baud rate */
WRITE_ATMEGA(UBRR0L, BAUD_PRESCALER);
WRITE_ATMEGA(UBRR0H,(BAUD_PRESCALER>>8));
/* Set frame format: 8 bit data + start bit + stop bit */
WRITE_ATMEGA(UCSR0C, 0x06);
/* Enable reciever and transmitter */
WRITE_ATMEGA(UCSR0B, 0xD8);
}
void __vector_23 (void)
{
call_interruptHandler();
}
void __vector_25 (void)
{
RX = UDR0;
flag_serial_receiver = 1;
sei();
}
void __vector_27 (void)
{
TX_complete = 1;
}
void call_interruptHandler()
{
intrs++;
if(intrs > LED_DELAY)
{
WRITE_ATMEGA(PORTB, 0xff<<i);
i++;
if(i==10)
{
WRITE_ATMEGA(PORTB, 0xff);
i = 1;
}
}
count = get_switchpressed();
if(count != 0)
{
WRITE_ATMEGA(PORTB, 0xff<<count);
intrs = 0;
}
//sei();
}
int get_switchpressed()
{
get_switch = READ_ATMEGA(PIND);
switch(get_switch) {
case 0xFE:
switch_pressed = 1;
break;
case 0xFD:
switch_pressed = 2;
break;
case 0xFB:
switch_pressed = 3;
break;
case 0xF7:
switch_pressed = 4;
break;
case 0xEF:
switch_pressed = 5;
break;
case 0xDF:
switch_pressed = 6;
break;
case 0xBF:
switch_pressed = 7;
break;
case 0x7F:
switch_pressed = 8;
break;
};
return (switch_pressed);
}
void ReadWriteSerialPort(void)
{
if(RX == 0x1A)
{
record = !record;
play_recorded_keys = 0;
}
else if(RX == 0x19)
{
record = 0;
play_recorded_keys = !play_recorded_keys;
}
if(record)
{
EEPROM_write(uiAdd++, RX);
}
if(uiAdd == 4096)
{
record = 0;
uiAddEnd = 4096;
}
else
uiAddEnd = uiAdd;
}
void EEPROM_write(unsigned int uiAddress, unsigned char ucData)
{
while(EECR & (1<<EEPE)); /* Wait for completion of previous write */
WRITE_ATMEGA(EEARH,(uiAddress>>8)); /* Set up address and Data Registers */
WRITE_ATMEGA(EEARL, uiAddress);
WRITE_ATMEGA(EEDR, ucData);
WRITE_ATMEGA(EECR, (EECR |(1<<EEMPE))); /* Write logical one to EEMPE */
WRITE_ATMEGA(EECR, (EECR |(1<<EERE))); /* Start eeprom write by setting EEPE */
}
unsigned char EEPROM_read(unsigned int uiAddress)
{
while(EECR & (1<<EEPE)); /* Wait for completion of previous write */
WRITE_ATMEGA(EEARH,(uiAddress>>8)); /* Set up address register */
WRITE_ATMEGA(EEARL,uiAddress);
WRITE_ATMEGA(EECR, (EECR |(1<<EERE))); /* Start eeprom read by writing EERE */
return EEDR; /* Return data from Data Register */
}
int main(void)
{
initialize();
while(1)
{
if(flag_serial_receiver == 1)
{
flag_serial_receiver = 0;
ReadWriteSerialPort();
}
if(play_recorded_keys)
{
unsigned char TX = EEPROM_read(uiAdd++);
if(uiAdd == 4096 || uiAdd >= uiAddEnd)
{
play_recorded_keys = 0;
uiAdd = 0;
}
while((UCSR0A & (1<<UDRE0)) == 0);
WRITE_ATMEGA(UDR0,TX);
while(TX_complete == 0);
TX_complete;
}
}
return(0);
}
这是header.h文件
#ifndef HEADER_H
#define HEADER_H
/*******PORTS******************/
#define PINA 0x0
#define DDRA 0x1
#define PORTA 0x2
#define PINB 0x3
#define DDRB 0x4
#define PORTB 0x5
#define PINC 0x6
#define DDRC 0x7
#define PORTC 0x8
#define PIND 0x9
#define DDRD 0xA
#define PORTD 0xB
#define PINE 0xC
#define DDRE 0xD
#define PORTE 0xE
#define PINF 0xF
#define DDRF 0x10
#define PORTF 0x11
#define PING 0x12
#define DDRG 0x13
#define PORTG 0x14
#define PINH 0xE0
#define DDRH 0xE1
#define PORTH 0xE2
#define PINJ 0xE3
#define DDRJ 0xE4
#define PORTJ 0xE5
#define PINK 0xE6
#define DDRK 0xE7
#define PORTK 0xE8
#define PINL 0xE9
#define DDRL 0xEA
#define PORTL 0xEB
/************TIMERS ************/
#define TCCR0A 0x24
#define TCCR0B 0x25
#define TCNT0 0x26
#define OCR0A 0x27
#define OCR0B 0x28
#define TIMSK0 0x4E
#define TIFR0 0x15
#define COM0A1 0x7
#define COM0A0 0x6
#define COM0B1 0x5
#define COM0B0 0x4
#define WGM02 0x3
#define WGM01 0x1
#define WGM00 0x0
#define CS02 0x2
#define CS01 0x1
#define CS00 0x0
#define OCIE0B 0x2
#define OCIE0A 0x1
#define TOIE0 0x0
/****** Interrupts *******/
#define EICRA 0x49
#define EICRB 0x4A
#define EIMSK 0x1D
#define PCICR 0x48
#define PCMSK0 0x4B
#define PCMSK1 0x4C
#define PCMSK2 0x4D
/************EEPROM************/
#define EECR 0x1F
#define EEDR 0x20
#define EEARL 0x21
#define EEARH 0x22
#define EEAR0 0
#define EEAR1 1
#define EEAR2 2
#define EEAR3 3
#define EEAR4 4
#define EEAR5 5
#define EEAR6 6
#define EEAR7 7
#define EEAR8 8
#define EEAR9 9
#define EEAR10 10
#define EEAR11 11
#define LSB 0
#define MSB 7
#define EERE 0
#define EEPE 1
#define EEMPE 2
#define EERIE 3
#define EEPM0 4
#define EEPM1 5
/************UART Status Control Registers & Data Registers **************/
/** USART3 **/
#define UCSR3A 0x130
#define UCSR3B 0x131
#define UCSR3C 0x132
#define UBRR3L 0x134
#define UBRR3H 0x135
#define UDR3 0x136
#define UDR3_TXB UDR3 /* transmit data buffer register */
#define UDR3_RXB UDR3 /* receive data buffer register */
/** USART2 **/
#define UDR2 0xD6
#define UBRR2H 0xD5
#define UBRR2L 0xD4
#define UCSR2C 0xD2
#define UCSR2B 0xD1
#define UCSR2A 0xD0
#define UDR2_TXB UDR2 /* transmit data buffer register */
#define UDR2_RXB UDR2 /* receive data buffer register */
/** USART1 **/
#define UDR1 0xCE
#define UBRR1H 0xCD
#define UBRR1L 0xCC
#define UCSR1C 0xCA
#define UCSR1B 0xC9
#define UCSR1A 0xC8
#define UDR1_TXB UDR1 /* transmit data buffer register */
#define UDR1_RXB UDR1 /* receive data buffer register */
/** USART0 **/
#define UDR0 0xC6
#define UBRR0H 0xC5
#define UBRR0L 0xC4
#define UCSR0C 0xC2
#define UCSR0B 0xC1
#define UCSR0A 0xC0
#define UDR0_TXB UDR0 /* transmit data buffer register */
#define UDR0_RXB UDR0 /* receive data buffer register */
#define TXB80 0
#define RXB80 1
#define UCSZ02 2
#define TXEN0 3
#define RXEN0 4
#define UDRIE0 5
#define TXCIE0 6
#define RXCIE0 7
#define MPCM0 0
#define U2X0 1
#define UPE0 2
#define DOR0 3
#define FE0 4
#define UDRE0 5
#define TXC0 6
#define RXC0 7
#define UCPOL0 0
#define UCSZ00 1
#define UCSZ01 2
#define USBS0 3
#define UPM00 4
#define UPM01 5
#define UMSEL00 6
#define UMSEL01 7
/******************************/
# define sei() __asm__ __volatile__ ("sei" ::)
# define cli() __asm__ __volatile__ ("cli" ::)
/* vectors in AVR are hard cided to a function by name */
extern void __vector_23 (void) __attribute__ ((interrupt));
/* interrupt is disabled at initilization */
extern void __vector_11 (void) __attribute__ ((interrupt));
/*******ADDR_MULTIPLIER********/
#define ADDR_MULTIPLIER 1
/*******Type Declaration*******/
#define UINT unsigned int
#define P_CHAR volatile unsigned char *
/***LEDs ON-OFF Declaration****/
#define LED_ON 0x00
#define LED_OFF 0xff
#endif
如果有人可以帮助我解决这个难题，我会非常感激，因为我很难淹没它。
提前致谢。
答案 0 :(得分：1)
嗯，检查整个代码有点困难，这很长，当然AVR上可能会有很多不好的东西......
我认为你应该首先删除所有LED的代码，然后单独尝试使用UART录像机，直到它工作。
我唯一看到的就是你：
unsigned char TX = EEPROM_read（uiAdd ++）;
但是你没有将uiAdd设置为从0开始......
无论如何，我不确定，因为很难遵循程序流程。