DS2438使用总结（温度、电压已调通，电流还在调）

power_lol

调了2天了，终于将DS2438调通了，着这里说说经验。其实说白了就是个时序问题，但是要注意两点：1>1-wire总线的复位和读写时间问题（这个相信做过的人一般都没有问题）；2>DS2438内部AD转换的时间问题（这个问题大家可能容易忽视）。在坛子里看过别人的程序，在其他网站上也找过程序，有很多人有这样的问题，就是采温度是准确的，采电压不正确，其实这就是忽视了DS2438的内部ADC转换时间的问题。其内部的电压采样用的是10bit的ADC，转换时间是10ms左右！！！电流采样的ADC是16bit的，采样时间是274.6ms左右（采样频率36.41HZ），所以启动AD转换之后一定等到转换完毕才去读取数据，这样才不会出错。我要采的电流范围是-60A~+60A，不知道这个芯片行不行，按计算用2m欧的电阻可以保证电压在其标称极限值-125mV~+125mV范围之内，晚上试试实际效果怎样。下面是在LPC2132上调试通过的代码：
#define PORTADDRESS  1<<14
#define MOVE         14  
#define  R    0.025  
// Pause for exactly 'tick' number of ticks = 0.25us
void tickDelay(uint16 tick) // Implementation is platform specific
{
while(tick--)
{
_nop_();
}
}
// 'tick' values
int A,B,C,D,E,F,G,H,I,J;

#define MK   4

//-----------------------------------------------------------------------------
// Set the 1-Wire timing to 'standard' (standard=1) or 'overdrive' (standard=0).
//
void SetSpeed(int standard)
{
    // Standard Speed
     A = 6 * MK;  //6us
    B = 64 * MK; //64us
    C = 60 * MK; //60
    D = 10 * MK; //10
    E = 9 * MK;  //9
    F = 55 * MK; //55
    G = 2;      //0
    H = 480 * MK;//480
    I = 70 * MK; //70
    J = 410 * MK;//410
  /* A = 1.5 * MK;
    B = 7.5 * MK;
    C = 7.5 * MK;
    D = 2.5 * MK;
    E = 0.75 * MK;
    F = 7 * MK;
    G = 2.5 * MK;
    H = 70 * MK;
    I = 8.5 * MK;
    J = 40 * MK;*/

}

// send 'databyte' to 'port'
void outp(unsigned port, int databyte)
{
//设置为输出
IO0DIR |= port;
//输出一个bit
if(databyte)
IO0SET |= port;
else
IO0CLR |= port;
}

// read byte from 'port'
int inp(unsigned port)
{
int i;
//设置为输入
IO0DIR &= ~port;
//读出一个bit
_nop_();
_nop_();
_nop_();
_nop_();
i = (IO0PIN & port)>>MOVE;
//设置为输出
IO0DIR |= port;
return  i;

}


//-----------------------------------------------------------------------------
// Generate a 1-Wire reset, return 1 if no presence detect was found,
// return 0 otherwise.
// (NOTE: Does not handle alarm presence from DS2404/DS1994)
//
int OWTouchReset(void)
{
        uint32 result;

        tickDelay(G);
        outp(PORTADDRESS,0x00); // Drives DQ low
        tickDelay(H);
        outp(PORTADDRESS,0x01); // Releases the bus
        tickDelay(I);
        result = inp(PORTADDRESS); // Sample for presence pulse from slave
        tickDelay(J); // Complete the reset sequence recovery
        if(result)
         return 1;//失败
        else
         return 0;//成功 // Return sample presence pulse result
}

//-----------------------------------------------------------------------------
// Send a 1-Wire write bit. Provide 10us recovery time.
//
void OWWriteBit(int bit)
{
if (bit)
{
    // Write '1' bit
    outp(PORTADDRESS,0x00); // Drives DQ low
    tickDelay(A);
    outp(PORTADDRESS,0x01); // Releases the bus
    tickDelay(B); // Complete the time slot and 10us recovery
}
else
{
    // Write '0' bit
    outp(PORTADDRESS,0x00); // Drives DQ low
    tickDelay(C);
    outp(PORTADDRESS,0x01); // Releases the bus
    tickDelay(D);
}
}

//-----------------------------------------------------------------------------
// Read a bit from the 1-Wire bus and return it. Provide 10us recovery time.
//
int OWReadBit(void)
{
    int result;

    outp(PORTADDRESS,0x00); // Drives DQ low
    tickDelay(A);
    outp(PORTADDRESS,0x01); // Releases the bus
    tickDelay(E);
    result = inp(PORTADDRESS) & 0x01; // Sample the bit value from the slave
    tickDelay(F); // Complete the time slot and 10us recovery

    return result;
}
//-----------------------------------------------------------------------------
// Write 1-Wire data byte
//
void OWWriteByte(uint8 data)
{
    uint8 loop,i;
     
    // Loop to write each bit in the byte, LS-bit first
    for (loop = 0; loop < 8; loop++)
    {
        //OWWriteBit(data & 0x01);
        i = data&0x01;
        if (i)
{
    // Write '1' bit
    outp(PORTADDRESS,0); // Drives DQ low
    tickDelay(A);
    outp(PORTADDRESS,1); // Releases the bus
    tickDelay(B); // Complete the time slot and 10us recovery
}
else
{
    // Write '0' bit
    outp(PORTADDRESS,0); // Drives DQ low
    tickDelay(C);
    outp(PORTADDRESS,1); // Releases the bus
    tickDelay(D);
}  // shift the data byte for the next bit
     data = data>>1;
    }
}

//-----------------------------------------------------------------------------
// Read 1-Wire data byte and return it
//
uint8 OWReadByte(void)
{
    uint8 loop, result=0,i;

    for (loop = 0; loop < 8; loop++)
    {
        // shift the result to get it ready for the next bit
        result >>= 1;
outp(PORTADDRESS,0x00); // Drives DQ low
    tickDelay(A);
    outp(PORTADDRESS,0x01); // Releases the bus
    tickDelay(E);
    i = (inp(PORTADDRESS) & 0x01); // Sample the bit value from the slave
    if(i)
     result |= 0x80;
    tickDelay(F); // Complete the time slot and 10us recovery
    }
    return result;
}

//-----------------------------------------------------------------------------
// Write a 1-Wire data byte and return the sampled result.
//
int OWTouchByte(int data)
{
    int loop, result=0;

    for (loop = 0; loop < 8; loop++)
    {
            // shift the result to get it ready for the next bit
            result >>= 1;

            // If sending a '1' then read a bit else write a '0'
            if (data & 0x01)
            {
                    if (OWReadBit())
                            result |= 0x80;
            }
            else
                    OWWriteBit(0);

            // shift the data byte for the next bit
            data >>= 1;
    }
    return result;
}

//-----------------------------------------------------------------------------
// Write a block 1-Wire data bytes and return the sampled result in the same
// buffer.
//
void OWBlock(unsigned char *data, int data_len)
{
        int loop;

        for (loop = 0; loop < data_len; loop++)
        {
                data[loop] = OWTouchByte(data[loop]);
        }
}

//-----------------------------------------------------------------------------
// Set all devices on 1-Wire to overdrive speed. Return '1' if at least one
// overdrive capable device is detected.
//
int OWOverdriveSkip(unsigned char *data, int data_len)
{
        // set the speed to 'standard'
        SetSpeed(1);

        // reset all devices
        if (OWTouchReset()) // Reset the 1-Wire bus
                return 0; // Return if no devices found

        // overdrive skip command
        OWWriteByte(0x3C);

        // set the speed to 'overdrive'
        SetSpeed(0);

        // do a 1-Wire reset in 'overdrive' and return presence result
        return OWTouchReset();
}
//-----------------------------------------------------------------------------
// Read and return the page data and SHA-1 message authentication code (MAC)
// from a DS2432.
//
uint8 ReadPageMAC(uint8 page, uint8 *page_data, uint8 *mac)
{
        uint8 i;
        unsigned short data_crc16, mac_crc16;
        // select the device
        if (OWTouchReset()) // Reset the 1-Wire bus
                return 0; // Return if no devices found

        OWWriteByte(0xCC); // Send Skip ROM command to select single device

        // read the page
        OWWriteByte(0xA5); // Read Authentication command
        OWWriteByte((page << 5) & 0xFF); // TA1
        OWWriteByte(0); // TA2 (always zero for DS2432)

        // read the page data
        for (i = 0; i < 32; i++)
                page_data = OWReadByte();
        OWWriteByte(0xFF);

        // read the CRC16 of command, address, and data
        data_crc16 = (uint16)OWReadByte();
        data_crc16 |= (uint16)(OWReadByte() << 8);

        // delay 2ms for the device MAC computation
        // read the MAC
        for (i = 0; i < 20; i++)
                mac = OWReadByte();

        // read CRC16 of the MAC
        mac_crc16 = (uint16)OWReadByte();
        mac_crc16 |= (uint16)(OWReadByte() << 8);

        // check CRC16...
        return 1;
}

uint8 initcommand(void)  
{     
unsigned char i=1,cnt=0;
    while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}   
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0x4E); // Write Scratchpad  
    OWWriteByte(0x00); // Write Page  
    OWWriteByte(0x07); // Write Cortrol  
    i=1;  
cnt=0;  
    while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0xBE); // Read Scratchpad  
    OWWriteByte(0x00); // Read 0th Page  
    i=1;  
cnt=0;  
    while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0x48); // Read Scratch Pad to Memory   
    OWWriteByte(0x00); // Copy 0th Page   
    tickDelay(250);  
    tickDelay(250);  
    tickDelay(250);  
    tickDelay(250);  
/*unsigned char i=1,cnt=0;           
    while(i)
    {
     i=OWTouchReset();
     if(cnt++>10)
     return 0;
    }  
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0x4E); // Write Scratchpad  
    OWWriteByte(0x00); // Write Page  
    OWWriteByte(0x07); // Write Cortrol  
    i=1;  
    cnt=0;
    while(i)
    {
     i=OWTouchReset();
     if(cnt++>10)
     return 0;
    }  
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0xBE); // Read Scratchpad  
    OWWriteByte(0x00); // Read 0th Page  
    i=1;  
    cnt=0;
    while(i)
    {
     i=OWTouchReset();
     if(cnt++>10)
     return 0;
    }
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0x48); // Read Scratch Pad to Memory   
    OWWriteByte(0x00); // Copy 0th Page   
tickDelay(20);  
return 1;*/
}  
//读取当前电池温度  
uint16 Read_Temperature(void)  
{  
unsigned char g[9];  
unsigned char i=1,j,cnt=0;  
uint16 u;   
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
OWWriteByte(0xCC); //Skip ROM  
OWWriteByte(0x44); // Start Conversion  
tickDelay(10);  
i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xB8); //READ SCRATCHPAD  
OWWriteByte(0x00); //READ 0TH PAGE  
i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xBE); // Read Scratch Pad  
OWWriteByte(0x00);  
for(j=0;j<9;j++)  
{  
g[j]=OWReadByte();  

}  
u=((g[2]&0x7f)*256+g[1]);  
return (u);  
}  

//读取电压转换值  
uint16 Read_Voltage(void)  
{     
uint8 b[9];  
    unsigned char i=1,j,cnt=0;  
    uint16 m;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}   
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0xB4); //WRITE VOLTAGE CORTROL  
    tickDelay(100);  
    i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0xB8); //READ SCRATCHPAD  
    OWWriteByte(0x00); //READ 0TH PAGE  
    i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}           
    OWWriteByte(0xCC); // Skip ROM  
    OWWriteByte(0xBE); //READ SCRATCHPAD  
    OWWriteByte(0x00); //READ 0TH PAGE  
    for(j=0;j<9;j++)  
    {  
        b[j]=OWReadByte();  
    }  
    for(j=0;j<9;j++)  
uart0_send_hex(b);
uart0_send_str("\r\n");
    m=((b[4]&0x03)*256+b[3])*0.01;  
    return (m);  
     
/*unsigned char g[9];  
unsigned char i=1,j,cnt=0;  
uint16 u;   
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
OWWriteByte(0xCC); //Skip ROM  
OWWriteByte(0xB4); // Start Conversion  
tickDelay(90);  
i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}
tickDelay(5);
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xB8); //READ SCRATCHPAD  
OWWriteByte(0x00); //READ 0TH PAGE  
i=1;  
cnt=0;  
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xBE); // Read Scratch Pad  
OWWriteByte(0x00);  
for(j=0;j<9;j++)  
{  
g[j]=OWReadByte();  

}  
for(j=0;j<9;j++)  
uart0_send_hex(g);
uart0_send_str("\r\n");
u=(uint16)((g[4]&0x03)<<8+g[3]);
return (u); */
}  

//读当前电流  
unsigned char Read_Current(void)  
{         
        
unsigned char c[9];  
unsigned char i=1,j,cnt=0;  
float n;   
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xB8); // Read Scratchpad  
OWWriteByte(0x00); // Read 0th Page  
i=1;  
cnt=0;
while(i)
{
i=OWTouchReset();
if(cnt++>10)
     return 0;
}  
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xBE); // Read Scratchpad  
OWWriteByte(0x00); // Read 0th Page  
for(j=0;j<9;j++)  
{  
c[j]=OWReadByte();  
}  
n=((c[6]&0x03)*256+c[5])/(4096*R);   
return (n);  
}  

uint8 ds2438_memory_recall(uint8 page)
{
uint8 result;
if(page > 7)
return 0;
result = OWTouchReset();
if(result)
{
OWWriteByte(0xCC); // Skip ROM  
//recall该page中的内容到scratchpad
OWWriteByte(0xB8); // Read Scratchpad  
}
return result;
}

uint8 ds2438_memory_readscratchpad(uint8 page,uint8 *data)
{
uint8 result;
if(page > 7)
return 0;
result = OWTouchReset();
if(result)
{
OWWriteByte(0xCC); // Skip ROM  
OWWriteByte(0xBE); // Read Scratchpad  
OWReadByte();
}