RS485多机通信程序(终结版AVR)

//名称:Delay()
//功能：延时程序
//QQQQQQQQQQQQQQQQQQQ
void Delay(int t)
{
while(t--);
}
void LDelay(int t) //延时程序(时间较长)
{
for(;t>0;t--)
{
Delay(4000);
}
}
//AD转换
#define ADC_REF_AVCC 0x40
#define MUX_ADC0 0x00
unsigned char ADC_Value;
void AD_Init(void)
{
//CLI();
ACSR |= (1< ADCSRA &=~(1< ADMUX &= 0x20;//清参考电压, ADCn输入端
{
while(t--);
}
void LDelay(int t)//延时程序(时间较长)
{
for(;t>0;t--)
{
Delay(4000);
}
}
//*************************************
//名称：LCDCOM()与LCDTATA（）LCDinit()
Delay(100);
PORTD&=~0x80;
}
void LCDTATA(unsigned char tata)
{
unsigned char temptata;
temptata = tata;
DDRC |=0X3F;
DDRD |=0X80;//pd7 output
PORTD&=~0x80;
}
void LCDinit()
{
LCDCOM(0X28);
Delay(3000);
LCDCOM(0X28);
Delay(3000);
LCDCOM(0X28);
Delay(3000);
LCDCOM(0X28);
Delay(3000); //while(t--) Delay(3000)以上
PORTD&=~0x80;
//LLLLLLLLLLL
tata = temptata&0x0f;
PORTC &=0XF0; //清零
Delay(100);
PORTC |=tata;//写指令
Delay(100);
PORTD|=0x80; //EN
Delay(100);
PORTD|=0x80; //EN
Delay(100);
PORTD&=~0x80;
//LLLLLLLLLLL
com = tempcom&0x0f;
PORTC &=0XF0; //清零
Delay(100);
PORTC |=com;//写指令
Delay(200);
PORTD|=0x80; //EN
unsigned char temp; //接收临时变量
unsigned char adr; //从机地址及标志位
const unsigned char LCD[]="IP01 IP02 IP03";
const unsigned char LCDASC[]={0X30,0X31,0X32,0X33,0X34,0X35,0x36,0x37,0x38,0x39};
{
LDelay(2);
//RRRRRRRRRRRRRRRRRRRRRRRR读数据
for(adr=1;adr<4;adr++)
{
SEND(adr); //发送地址寻找从机,地址ADR从01-03
LDelay(20); //延时
}
//RRRRRRRRRRRRRRRRRRRRRRRR读数据
{
unsigned char ADC_dat;
ADCSRA |= (1< while(ADCSR&(1< ADC_dat = ADCH;
LCDCOM(0X08);
Delay(3000);
LCDCOM(0X01);
Delay(3000);
LCDCOM(0X06);
Delay(3000);
LCDCOM(0X0c);
Delay(3000);
LCDCOM(0x01);//清屏
}
//============2 找2号从机，重复步骤1。完了再发03。这样轮换的通信。
程序在实际硬件上已经调试成功，验证了正确性，下面把程序贴出来供大家参考。
采用9位数据帧
下面是程序,使用ICCAVR软件编写
主机程序：
#include
#include
#pragma interrupt_handler uartrupt:12
UCSRA=0X0;
UCSRB=0X0;
//UCSRA=RXC|TXC|UDRE|FE|DOR|PE|U2X|MPCM(10100001)
UCSRA=0X0;//接收数据
//UCSRC=URSEL|UMSEL|UPM1|UPM0|USBS|UCSZ1|UCSZ0|UCPOL
UCSRC|=0x86 ; //设置数据位
if(adr==2){LCDCOM(0xc0+5);TOLCD(temp);}
if(adr==3){LCDCOM(0xc0+10);TOLCD(temp);}
}
//======================
//名称：主函数
//======================
void main()
unsigned char LCDA=0;
unsigned char LCDB=0;
unsigned char LCDC=0;
//QQQQQQQQQQQQQQQQQQQ
//名称:Delay()
//功能：延时程序
//QQQQQQQQQQQQQQQQQQQ
void Delay(int t)
主机：
MAX487的RE和DE连在一起，并接到PD3
PC0-PC3接1602液晶的D4-D7 （只用4条数据线）
PD7接LCD E
PC4接LCD RW
PC5接LCD RS
工作过程：
从机等间隔进行进行AD采样
1． 主机发送地址(adr)：01 寻找01从机 ,01号从机收到后，把AD采回来的数据发给主机，主机把数
{unsigned char str;
DDRD|=0X08; //MAX485允许输出
PORTD|=0X08;
USARTinit();
LCDinit();
DDRB |= 0X03; //PORTB OUT
Delay(4000);
Delay(4000);
//液晶第一行:IP1 IP2 IP3
{
DDRD|=0X08; //MAX485允许输出
PORTD|=0X08;
UCSRB|=0x01; //TXB8=0发地址
Delay(1000);
while(!UDRE);
UDR=mydata;
Delay(1000); //必有
PORTD&=~0X08; //发送后立即转为接收等从机发来数据
DDRD |=0X80;//pd7 output
PORTC &=~0x20; //RS = 0
com = com>>4;
com =com&0x0f;
PORTC &=0XF0; //低4位清零
Delay(100);
PORTC |=com;//写指令
Delay(100);
ADMUX |=0X40|MUX_ADC0|(1< ADCSRA |= (1< ADCSRA |= (1< ADCSRA |=0x01;//2分频
SFIOR = 0X00;
ADCSRA |= (1< ADCSRA |= (1< }
unsigned char Read_ADC(void)
LCDCOM(0x80); //第一行
while(LCD[str]!='\0') //字符串是否完成
{
LCDTATA(LCD[str]);
str++;//
}
str=0; //跳出来之后清空str=0切记!切记!
//液晶第一行
while(1)
//名称：USARTinit()
//功能：串行通信初始化,设置引脚功能，波特率，通信方式
//波特率=fosc/16(ubrr+1)
//======================
void USARTinit()
{
UBRRL=25; //波特率2400 //UCSRA 正常波特率
//UBRRH=0x00;
PORTC|=0x20; //RS = 1
tata= tata>>4;
tata &= 0x0f;
PORTC &=0XF0; //清零
Delay(100);
PORTC |=tata;//写指令
Delay(100);
PORTD|=0x80; //EN
Delay(100);