STM32在线水质氨氮检测仪变送器开发PCB和单片机源程序

ID:571920 · 发表于 2019-6-25 17:06

开发的氨氮检测仪，采用CAN总线输出，源程序和PCB见附件：
技术参数如下：

技术参数

量程：0~100ppm（量程可调）

精度：0.1ppm

输出信号：CAN总线

传输协议：Modbus RTU

485波特率：9600（默认）

CAN频率：500K（默认）

温度范围：0-80℃

温度补偿：自动补偿

校准：命令方式（软件校准）

工作电压：5V/12V

电缆长度：标配5米

Altium Designer画的原理图和PCB图如下：(51hei附件中可下载工程文件)

单片机源程序如下:

#include "led.h"
#include "delay.h"
#include "sys.h"
#include "usart.h"
#include "adc.h"
#include "dma.h"
#include "can.h"
#include "rs485.h"
#include "math.h"
#include "stmflash.h"
//要写入到STM32 FLASH的字符串数组
u16 flash[10],read[10];//第一位判断是否是初始设置
#define SIZE sizeof(write) //数组长度
#define FLASH_SAVE_ADDR 0X08040000 //设置FLASH 保存地址(必须为偶数，且其值要大于本代码所占用FLASH的大小+0X08000000)
u16 get[20000];
float n,m;
int a,phase,crc,rsp;
int array[]={115200,57600,38400,28800,19200,14400,9600,4800,2400,1200};
u16 brq;
int main(void)
{
u8 rs485[8],send485[8],len;
u8 cnt=0;
u8 canbuf[8],canget[8];
int i;
float temp,nh;
delay_init();
uart_init(9600); //串口初始化为9600
LED_Init();
if(flash[0]==10)RS485_Init(array[flash[4]]);
else RS485_Init(9600); //初始化RS485
MYDMA_Config(DMA1_Channel1,(u32)&ADC1->DR,(u32)get,1904);//DMA1通道1,外设为串口1,存储器为SendBuff,长度应为转换通道数×转换次数
//采样952个点，50hz信号 20ms一周期，采样952个点约为21us采样一次，即12Mhz频率 239.5+12.5个周期252 252=12*21
Adc_Init();
DMA_Cmd(DMA1_Channel1, ENABLE); //使能ADC DMA1 所指示的通道
ADC_SoftwareStartConvCmd(ADC1, ENABLE); //使能指定的ADC1的软件转换启动功能
STMFLASH_Read(FLASH_SAVE_ADDR,(u16*)flash,10);
if(flash[0]==10)CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,flash[3],CAN_Mode_Normal);
else
CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,4,CAN_Mode_Normal);//36M/((8+9+1)*4)=500Kbps,brp可以设置从0~1024
while(1)
{
// while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET);作为保留防止第一位数据丢失
//MYDMA_Enable(DMA1_Channel1);
LED1=!LED1;
for(a=0;a<100;a++) //电压值求均值，叠加100次再除以100
{
for(i=0;i<1902;i+=2)
{
n+=get[i]*get[i];
}
n=sqrt(n/952);
nh+=n*(3.3/4096);
n=0;
}
printf("nh4 is %f\r\n",nh/100);
if(nh<51.3)
temp=1.01*nh-41.814;
else temp=12*nh-614;
printf("nh4 is %f\r\n",temp);
nh=0;
// for(i=1;i<11;i+=2)
// {
// printf("wendu is %f\r\n",(float)get[i]*(3.3/4096));
// m+=get[i]*get[i];
// }
// m=sqrt(m/952);
// printf("wendu is %f\r\n",(float)(m/100)*(3.3/4096));
// m=0;
canbuf[2]=temp;
temp-=canbuf[2];
temp*=100;
canbuf[3]=temp;
LED0=!LED0;
RS485_Receive_Data(rs485,&len);
if (rs485[0]==0xad)
{
switch (rs485[1])
{
case 0x02: //设置485频率
send485[0]=0xad;
send485[1]=0x02;
rsp=(int)rs485[3];
if(rsp<0&&rsp>9) {send485[2]=0x11; //如频率设置错误则返回错误代码 0xad 0x11 0x11 0x11 0x65 0xa7
send485[3]=0x11;
crc=CRC16_2(send485,4);
send485[4]=(unsigned char)(crc&0xff);
send485[5]=(unsigned char)((crc&0xff00)>>8);
RS485_Send_Data(send485,6); }
else{RS485_Init(array[rsp]);
flash[1]=10;
flash[4]=rsp;
//设置成功返回 0xad 0x02 0x00 0x00 0x57 0x91
send485[2]=0x00;
send485[3]=0x00;
crc=CRC16_2(send485,4);
send485[4]=(unsigned char)(crc&0xff);
send485[5]=(unsigned char)((crc&0xff00)>>8);
RS485_Send_Data(send485,6);}
break;
case 0x03: //查询NH4值
send485[0]=0xad;
send485[1]=0x03;
crc=CRC16_2(send485,4);
send485[4]=(unsigned char)(crc&0xff);
send485[5]=(unsigned char)((crc&0xff00)>>8);
RS485_Send_Data(send485,6);
break;
case 0x04: //校准斜率
switch(canget[2])
{
case 0x00:
send485[0]=0xad;
send485[1]=0x04;
crc=CRC16_2(send485,4);
send485[4]=(unsigned char)(crc&0xff);
send485[5]=(unsigned char)((crc&0xff00)>>8);
RS485_Send_Data(send485,6);
}
}
}
Can_Receive_Msg(canget);
if (canget[0]==0xad)
{
switch (canget[1])
{
case 0x02: //设置can频率
canbuf[0]=0xad;
canbuf[1]=0x02;
phase=(int)canget[3]+(int)(256*canget[2]);
if(2000%phase!=0) {canbuf[2]=0x11; //如频率设置错误则返回错误代码 0xad 0x11 0x11 0x11 0x65 0xa7
canbuf[3]=0x11;
crc=CRC16_2(canbuf,4);
canbuf[4]=(unsigned char)(crc&0xff);
canbuf[5]=(unsigned char)((crc&0xff00)>>8);
Can_Send_Msg(canbuf,6); }
else{brq=(u16)(2000/phase);
flash[0]=10;
flash[3]=brq;
STMFLASH_Write(FLASH_SAVE_ADDR,(u16*)flash,10);
CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,brq,CAN_Mode_Normal);//设置成功返回 0xad 0x02 0x00 0x00 0x57 0x91
canbuf[2]=0x00;
canbuf[3]=0x00;
crc=CRC16_2(canbuf,4);
canbuf[4]=(unsigned char)(crc&0xff);
canbuf[5]=(unsigned char)((crc&0xff00)>>8);
Can_Send_Msg(canbuf,6);}
break;
case 0x03: //查询NH4值
canbuf[0]=0xad;
canbuf[1]=0x03;
crc=CRC16_2(canbuf,4);
canbuf[4]=(unsigned char)(crc&0xff);
canbuf[5]=(unsigned char)((crc&0xff00)>>8);
Can_Send_Msg(canbuf,6);
break;
case 0x04: //校准斜率
switch(canget[2])
{
case 0x00:
canbuf[0]=0xad;
canbuf[1]=0x04;
crc=CRC16_2(canbuf,4);
canbuf[4]=(unsigned char)(crc&0xff);
canbuf[5]=(unsigned char)((crc&0xff00)>>8);
Can_Send_Msg(canbuf,6);
}
}
}
delay_ms(250);
}
}