我用delphi和单片机进行串口通信，在串口调试助手里通过，但实际硬件通讯时，不能接收数据。

Posted 2023-03-28

procedure TForm1.FormCreate(Sender: TObject);
begin
MSComm1.CommPort:=1;
MSComm1.Settings:='9600,n,8,1';
MSComm1.InBufferCount:=0;
MSComm1.InputLen:=0;
MSComm1.InputMode:=ComInputModeBinary; //ComInputModeText
MSComm1.RThreshold:=1;
// MSComm1.PortOpen:=true;
end;

procedure TForm1.Button4Click(Sender: TObject);
var
send:olevariant;
count,i:integer;
begin
count:=1;
send:=vararraycreate([0,count-1],varbyte);
for i:= 0 to count-1 do
send[i]:=10;
if MSComm1.PortOpen=false then
MSComm1.PortOpen:=true;
MSComm1.Output:=send;
end;

procedure TForm1.MSComm1Comm(Sender: TObject);
var
recstr:Olevariant;

begin
if MSComm1.CommEvent=2 then
begin
recstr:=MSComm1.Input;
end;
edit1.Text:=inttostr(recstr[0]);
//edit2.Text:=inttostr(recstr[1]);
//edit3.Text:=inttostr(recstr[2]);
//edit4.Text:=inttostr(recstr[3]);
end;

单片机得程序如下，用的是atmega16l，晶振是4M
#include <iom16v.h>
#include <macros.h>

unsigned char dat[4]=0,0,255,255;//0,0,0xA,
unsigned char temp;

void port_init(void)

PORTA = 0x00;
DDRA = 0x00;
PORTB = 0x00;
DDRB = 0x00;
PORTC = 0x00; //m103 output only
DDRC = 0x00;
PORTD = 0xFF;
DDRD = 0x02;


//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)

UCSRB = 0x00; //disable while setting baud rate
UCSRA = 0x02;
UCSRC = BIT(URSEL) | 0x06;
UBRRL = 0x33; //set baud rate lo
UBRRH = 0x00; //set baud rate hi
UCSRB = 0x98;


void uart0_send(unsigned char i)

while(!(UCSRA & (1<<UDRE)));
UDR=i;


void str_send(unsigned char *s)

while(*s)

uart0_send(*s);
s++;



#pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
void uart0_rx_isr(void)

//uart has received a character in UDR
temp=UDR;


//call this routine to initialize all peripherals
void init_devices(void)

//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
uart0_init();

MCUCR = 0x00;
GICR = 0x00;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialized


//
void main(void)

unsigned char i;
init_devices();
//insert your functional code here...
while(1)

if(temp==0x0A)

SREG=0;
for(i=0;i<4;i++)
uart0_send(dat[i]);

temp=0;
SEI();
//while(1);

再调一下单片机的BAUD因子，因为PC的BAUD比较准，单片机不太准，容易误码，再有就是尽量下调波特率，从1200开始试 参考技术A 你的晶振不是接上就可以了，而且还要设置AVR单片机的熔丝位，使单片机支持你的晶振才行，（AVR默认的时钟是内部8M RC振荡电路，而且振荡电路不精确，用于串口会出现错误），硬件的时钟电源和复位电路都要再检查检查