Программирование умных аккумуляторов (Smart Battery) на микроконтроллерах Atmel семейства Xmega

bool InitI2cMaster(U16 u16BitRateInKhz, U32 u32SystemClockInKhz)
{
    // test for correct input frequency
    if ((u32SystemClockInKhz / 2 / u16BitRateInKhz - 5) < 0)
    {
        return false;
    }
    
    TWIC.CTRL = 0;      // clear common register
    
    // enable TWI / I2C / SMBUS
    TWIC.MASTER.CTRLA = TWI_MASTER_ENABLE_bm;
    
    // set timeout for SMBUS compatibility
    TWIC.MASTER.CTRLB = TWI_MASTER_TIMEOUT_50US_gc;
    TWIC.MASTER.CTRLC = 0;
    
    // force initial bus state to idle
    TWIC.MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;
    
    // set baud rate
    TWIC.MASTER.BAUD = u32SystemClockInKhz / 2 / u16BitRateInKhz - 5;
    
    return true;
}

bool I2cSend1Byte(U8 u8Address, U8 u8Data, bool bNextOpChangeDirection, bool bNotStandard)
{
    U16 u16TimeoutCounter;
    
    if (GetI2cBusState() == TWI_MASTER_BUSSTATE_BUSY_gc)
    {
        // aribtration lost
        if (IsI2cArbLost())
        {
            TWIC.MASTER.STATUS = TWI_MASTER_ARBLOST_bm;
        }
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    // send slave address to the I2C bus
    TWIC.MASTER.ADDR = u8Address & ~0x01;
    
    // check bus state after address sent
    u16TimeoutCounter = 0;
    while (u16TimeoutCounter++ <= C_MaxTimeout)
    {
        // aribtration lost
        if (IsI2cWif() && IsI2cArbLost())
        {
            TWIC.MASTER.STATUS = TWI_MASTER_ARBLOST_bm;
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // slave not acknoledge
        if (IsI2cWif() && IsI2cRxAck())
        {
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // slave acknoledge
        if (IsI2cWif() && !IsI2cRxAck())
        {
            break;
        }
    }
    
    // no activity on I2C bus
    if (u16TimeoutCounter == C_MaxTimeout)
    {
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    TWIC.MASTER.DATA = u8Data;
    
    u16TimeoutCounter = 0;
    while (u16TimeoutCounter++ <= C_MaxTimeout)
    {
        // aribtration lost
        if (IsI2cArbLost())
        {
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // slave not acknowledge
        if (IsI2cWif() && IsI2cRxAck())
        {
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // data is sent successfully
        if (IsI2cWif() && IsI2cClkHold())
        {
            break;
        }
    }
    
    // no activity on I2C bus
    if (u16TimeoutCounter == C_MaxTimeout)
    {
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    if (bNextOpChangeDirection)
    {
        if (bNotStandard)
        {
            // for used smart battery chip
            // no repeat start command, just stop and start again
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        }
        else
        {
            // for standard SMbus 1.1
            // repeated start
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_REPSTART_gc;
        }
        
        // delay between stop and start
        for (u16TimeoutCounter = 0; u16TimeoutCounter < C_MaxTimeout; u16TimeoutCounter++);
    }
    else
    {
        // stop data transmition
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
    }
    
    return true;
}

bool I2cReceive1Byte(U8 u8Address, U8 *u8Data)
{
    U16 u16TimeoutCounter;
    
    if (GetI2cBusState() == TWI_MASTER_BUSSTATE_BUSY_gc)
    {
        // aribtration lost
        if (IsI2cArbLost())
        {
            TWIC.MASTER.STATUS = TWI_MASTER_ARBLOST_bm;
        }
        TWIC.MASTER.STATUS = TWI_MASTER_BUSSTATE_IDLE_gc;
        return false;
    }
    
    // send slave address to the I2C bus
    TWIC.MASTER.ADDR = u8Address | 0x01;
    
    // check bus state after address sent
    u16TimeoutCounter = 0;
    while (u16TimeoutCounter++ <= C_MaxTimeout)
    {
        // aribtration lost
        if (IsI2cWif() && IsI2cArbLost())
        {
            TWIC.MASTER.STATUS = TWI_MASTER_ARBLOST_bm;
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // slave not acknowledge
        if (IsI2cRif() && IsI2cRxAck())
        {
            TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
            return false;
        }
        
        // slave acknowledge
        if (IsI2cRif() && !IsI2cRxAck())
        {
            break;
        }
    }
    
    // no activity on I2C bus
    if (u16TimeoutCounter == C_MaxTimeout)
    {
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    u16TimeoutCounter = 0;
    while (u16TimeoutCounter++ <= C_MaxTimeout)
    {
        // data is ready to read
        if (IsI2cRif() && IsI2cClkHold())
        {
            break;
        }
    }
    
    // no activity on I2C bus
    if (u16TimeoutCounter == C_MaxTimeout)
    {
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    // get data byte
    *u8Data = TWIC.MASTER.DATA;
    
    // send nack to indicate no further read allowed
    // and send stop to finish transfer
    TWIC.MASTER.CTRLC = TWI_MASTER_ACKACT_bm | TWI_MASTER_CMD_STOP_gc;
    
    return true;
}

bool I2cReceive2Bytes(U8 u8Address, U8 *u8Data0, U8 *u8Data1)
{
    ...
    
    // get the first data byte
    *u8Data0 = TWIC.MASTER.DATA;
    
    // send acknowledge
    TWIC.MASTER.CTRLC = TWI_MASTER_CMD_RECVTRANS_gc;
    
    u16TimeoutCounter = 0;
    while (u16TimeoutCounter++ <= C_MaxTimeout)
    {
        // data is ready to read
        if (IsI2cRif() && IsI2cClkHold())
        {
            break;
        }
    }
    
    // no activity on I2C bus
    if (u16TimeoutCounter == C_MaxTimeout)
    {
        TWIC.MASTER.CTRLC = TWI_MASTER_CMD_STOP_gc;
        return false;
    }
    
    // get the second data byte
    *u8Data1 = TWIC.MASTER.DATA;
    
    // send nack to indicate no further read allowed
    // and send stop to finish transfer
    TWIC.MASTER.CTRLC = TWI_MASTER_ACKACT_bm | TWI_MASTER_CMD_STOP_gc;
    
    return true;
}

bool ProcessSbsCommandS1bR1b(U8 u8Address, U8 u8Data2Send, U8 *u8Data0)
{
    U16 u16TimeoutCounter;
    bool bResult = false;
    
    // send command - 1 byte
    bResult = I2cSend1Byte(u8Address, u8Data2Send, true, true);
    
    if (!bResult)
    {
        return bResult;
    }
    
    // read data - 1 byte
    bResult = I2cReceive1Byte(u8Address, u8Data0);
    
    return bResult;
}

bool ProcessSbsCommandS1bR2b(U8 u8Address, U8 u8Data2Send, U8 *u8Data0, U8 *u8Data1)
{
    U16 u16TimeoutCounter;
    bool bResult = false;
    
    // send command - 1 byte
    bResult = I2cSend1Byte(u8Address, u8Data2Send, true, true);
    
    if (!bResult)
    {
        return bResult;
    }
    
    // read data - 2 byte
    bResult = I2cReceive2Bytes(u8Address, u8Data0, u8Data1);
    
    return bResult;
}

#define C_Pca9543ApwAddress 0xE0    // A1, A0 is set to zero
 
#define C_Pca9543ApwChannel1 1
#define C_Pca9543ApwChannel2 2
 
#define C_BatteryAddress 0x16
 
#define C_BatteryCmdGetTemperature              0x08
#define C_BatteryCmdGetVoltage                  0x09
#define C_BatteryCmdGetAverageCurrent           0x0b
#define C_BatteryCmdGetRelativeStateOfCharge    0x0d
 
U8 GetPowerLevels(U8 *u8PowerLevelAcc1, U8 *u8PowerLevelAcc2)
{
    // выбор 1-го канала
    bResult = I2cSend1Byte( C_Pca9543ApwAddress, 
                                C_Pca9543ApwChannel1, 
                                false,
                                false);
        // получение данных от аккумулятора - относительный заряд
        bResult = ProcessSbsCommandS1bR1b(C_BatteryAddress, 
                                            C_BatteryCmdGetRelativeStateOfCharge, 
                                            u8PowerLevelAcc1);
        
        if (!bResult)
        {
            // батарея не подключена, проверить по состоянию переключателя питания
            *u8PowerLevelAcc1 = 0;
        }
        //============== other values ======================================
        ...
        // получение температуры
        bResult = ProcessSbsCommandS1bR2b(C_BatteryAddress, 
                                            C_BatteryCmdGetTemperature, 
                                            &g_u8DataReceived0, 
                                            &g_u8DataReceived1);
        
        g_u16BatteryTemperature = (g_u8DataReceived1 << 8) + g_u8DataReceived0;
        ...
        //============== other values end ==================================
        
        // выбор 2-го канала
        bResult = I2cSend1Byte( C_Pca9543ApwAddress, 
                                C_Pca9543ApwChannel2, 
                                false,
                                false);
        
        // получение данных от аккумулятора - относительный заряд
        bResult = ProcessSbsCommandS1bR1b(C_BatteryAddress, 
                                            C_BatteryCmdGetRelativeStateOfCharge, 
                                            u8PowerLevelAcc2);
        if (!bResult)
        {
            // батарея не подключена, проверить по состоянию переключателя питания
            *u8PowerLevelAcc2 = 0;
        }
}
 
int main(void)
{
    ...
    InitI2cMaster(C_I2cBitRateInKhz, ClockSystem.u32CpuClockInKhz);
    ...
    u8Result =GetPowerLevels(& g_au8PowerLevelBat[0], & g_au8PowerLevelBat[1]);
    ...
}