File content as of revision 3:2035a4a54d3f:

#include "AK9752.h"
#include "AK9752_reg.h"

/**
 * Combine low and high int8_t bytes of Temp/IR data and store in int16_t variable
 */
#define CONV16I(high,low)  ((int16_t)(((high) << 8) | (low)))

#define LEN_ONE_BYTE            1       /**<! Data length of 1 byte data. */
#define LEN_BUF_THRESHOLD       8       /**<! Data length of Threshold settings. From THIRH to THTMPL */
#define LEN_BUF_IR_DATA         7       /**<! Data length of IR sensor data: ST1,INTCAUSE,IR(16),TMP(16),ST2. */
#define VAL_SOFTWARE_RESET      0x01    /**<! Software reset value. */
#define ST1_STATUS_FLAG_DRDY    0x01    /**<! Data Ready*/
#define INT_STATUS_FLAG_DR      0x01    /**<! Data Read */
#define INT_STATUS_FLAG_TMPL    0x02    /**<! Temp low threshold reached */ 
#define INT_STATUS_FLAG_TMPH    0x04    /**<! Temp high threshold reached */
#define INT_STATUS_FLAG_IRL     0x08    /**<! IR low threshold reached */
#define INT_STATUS_FLAG_IRH     0x10    /**<! IR high threshold reached */
#define INT_STATUS_MASK         0x1F    /**<! Mask highest 3 bits of status */
#define ST2_STATUS_FLAG_DOR     0x01    /**<! Data overrun (data read is required) */


AK9752::AK9752() {
}

void AK9752::init(I2C *conn, SlaveAddress addr) {
    slaveAddress = addr;
    connection = conn;
}

AK9752::Status AK9752::checkConnection() {
    AK9752::Status status = AK9752::SUCCESS;
    
    // Gets the WIA register value.
    char buf[2];
    if ((status=AK9752::read(AK9752_REG_ADDR_WIA1, buf, 2)) != SUCCESS) {
        return status;
    }

    // Checks the obtained value equals to the supposed value.
    if ( (buf[0] != AK9752_REG_VALUE_WIA1) ||  (buf[1] != AK9752_REG_VALUE_WIA2) ) {
        return AK9752::ERROR;
    }
    
    return status;
}

AK9752::Status AK9752::read(char registerAddress, char *buf, int length) {
    // Tell slave address of where to read data
    if (connection->write((slaveAddress << 1), &registerAddress, LEN_ONE_BYTE) != 0) {
        // I2C write failed.
        return AK9752::ERROR_I2C_WRITE;
    }
    
    // Read register data (converts 7-bit address to 8-bit)
    if (connection->read((slaveAddress << 1), buf, length) != 0) {
        // I2C read failed.
        return AK9752::ERROR_I2C_READ;
    }
    
    return AK9752::SUCCESS;
}

AK9752::Status AK9752::write(char registerAddress, const char *buf, int length) {
    int bufLength = length + 1; // Increase size to account for address byte
    char data[bufLength];

    // Creates data to be sent.
    data[0] = registerAddress;           // Place register address in first byte 
    for (int i=0; i < length; i++) {
        data[1+i] = buf[i];              // Load write data starting at second byte (i.e. data[1])
    }
    
    // Initiate I2C write command
    if (connection->write((slaveAddress << 1), data, bufLength) != 0) {
        // I2C write failed.
        return AK9752::ERROR_I2C_WRITE;
    }

    return AK9752::SUCCESS;
}

AK9752::Status AK9752::getInterruptEnable(InterruptStatus *intStatus){
    Status status;
    
    char buf = 0;
    if((status=read(AK9752_REG_ADDR_INTEN, &buf, LEN_ONE_BYTE)) != SUCCESS) {
        return status;  // Read failed
    }
    
    // Set interrupt status flags individually
    intStatus->irh = ((buf & INT_STATUS_FLAG_IRH) > 0) ? true : false;
    intStatus->irl = ((buf & INT_STATUS_FLAG_IRL) > 0) ? true : false;
    intStatus->tmph = ((buf & INT_STATUS_FLAG_TMPH) > 0) ? true : false;
    intStatus->tmpl = ((buf & INT_STATUS_FLAG_TMPL) > 0) ? true : false;
    intStatus->dr = ((buf & INT_STATUS_FLAG_DR) > 0) ? true : false;
    
    return SUCCESS;     // Read succeeded
}

AK9752::Status AK9752::setInterruptEnable(const InterruptStatus *intStatus) {
    char buf = 0;
    
    // If interrupt bit is 1, set corresponding buf bit to 1, otherwise set  to 0
    buf += intStatus->irh ? INT_STATUS_FLAG_IRH : 0;
    buf += intStatus->irl ? INT_STATUS_FLAG_IRL : 0;
    buf += intStatus->tmph ? INT_STATUS_FLAG_TMPH : 0;
    buf += intStatus->tmpl ? INT_STATUS_FLAG_TMPL : 0;
    buf += intStatus->dr ? INT_STATUS_FLAG_DR : 0;
    
    // Perform interrupt status write operation
    Status status;
    if ((status=write(AK9752_REG_ADDR_INTEN, &buf, LEN_ONE_BYTE)) != SUCCESS) {
        return status;    
    }
    
    // Read back the interrupt status
    char readback = 0;
    if ((status=read(AK9752_REG_ADDR_INTEN, &readback, LEN_ONE_BYTE)) != SUCCESS) {
        return status;  // Read back operation failed
    }
    
    if ((readback & INT_STATUS_MASK) != buf) {
        return ERROR;   // Read back succeeded, but values incorrect
    }
    
    return SUCCESS;
}

AK9752::Status AK9752::setThreshold(const Threshold *th) {
    Status status;
    char buf[LEN_BUF_THRESHOLD];
    
    // Mask off irrelevant byte, cast 8-bit values to 16-bit
    // 
    buf[0] = (char)(((uint16_t)th->thirh & 0x00FF));         // THIRHL Register
    buf[1] = (char)(((uint16_t)th->thirh & 0xFF00) >> 8);    // THIRHH Register
    buf[2] = (char)(((uint16_t)th->thirl & 0x00FF));         // THIRLL Register
    buf[3] = (char)(((uint16_t)th->thirl & 0xFF00) >> 8);    // THIRLH Register
    buf[4] = (char)(((uint16_t)th->thtmph & 0x00FF));        // THTMPHL Register
    buf[5] = (char)(((uint16_t)th->thtmph & 0xFF00) >> 8);   // THTMPHH Register
    buf[6] = (char)(((uint16_t)th->thtmpl & 0x00FF));        // THTMPLL Register
    buf[7] = (char)(((uint16_t)th->thtmpl & 0xFF00) >> 8);   // THTMPLH Register
    
    // Perform threshold register write operaton
    if ((status=write(AK9752_REG_ADDR_THIRHL, buf, LEN_BUF_THRESHOLD)) != SUCCESS) {
        return status;  // Write operation failed
    }

    return SUCCESS;     // Write operation succeeded
}

AK9752::Status AK9752::getThreshold(Threshold *th) {
    Status status;
    char buf[LEN_BUF_THRESHOLD];
    
    // Perform threshold register read operation
    if ((status=read(AK9752_REG_ADDR_THIRHL, buf, LEN_BUF_THRESHOLD)) != SUCCESS) {
        return status;  // Read operation failed
    }
    
    // Combine low and high bytes of data
    th->thirh = CONV16I(buf[1], buf[0]);
    th->thirl = CONV16I(buf[3], buf[2]);
    th->thtmph = CONV16I(buf[5], buf[4]);
    th->thtmpl = CONV16I(buf[7], buf[6]);
    
    return SUCCESS;     // Read operation succeeded
}

AK9752::Status AK9752::getOperationMode(OperationMode *mode, FcTmp *fc_tmp, FcIr *fc_ir){
    Status status;
    
    char buf[2];
    if ((status=read(AK9752_REG_ADDR_CNTL1, buf, 2)) != SUCCESS) {
        return status;  // Read operation failed
    }
    
    *fc_tmp = AK9752::FcTmp((buf[0] & 0x1C)>>2);    // Read CNTL1[2]-CNTL1[4]
    *fc_ir = AK9752::FcIr(buf[0] & 0x03);           // Read CNTL1[0]-CNTL1[1]
    *mode = AK9752::OperationMode(buf[1] & 0x03);   // Read CNTL2[0]-CNTL2[1]
    
    return SUCCESS;     // Read operation succeeded
}

AK9752::Status AK9752::setOperationMode(OperationMode mode, FcTmp fc_tmp, FcIr fc_ir){
    Status status;
    
    char buf[2];
    buf[0] = (fc_tmp<<2 | fc_ir&0x03);  // Combine FCTMP & FCIR in 1 byte
    buf[1] = mode;
    
    // Write 2 bytes starting from CNTL1 -> write CNTL1 and CNTL2
    if ((status=write(AK9752_REG_ADDR_CNTL1, buf, 2)) != SUCCESS) {
        return status;  // Write operation failed
    }
    return SUCCESS;     // Write operation succeeded
}

AK9752::Status AK9752::reset() {
    Status status;
    
    char val = VAL_SOFTWARE_RESET;      // char instance required for write()
    if ((status=write(AK9752_REG_ADDR_CNTL3, &val, LEN_ONE_BYTE)) != SUCCESS) {
        return status;  // Write operation failed
    }    
    return SUCCESS;     // Write operation succeeded
}

AK9752::Status AK9752::getSensorData(SensorData *data) {
    
    char buf[LEN_BUF_IR_DATA];
    
    // Read 7 bytes starting at ST1: reads ST1, INTCAUSE, data and ST2 at once
    if ((read(AK9752_REG_ADDR_ST1, buf, LEN_BUF_IR_DATA)) != SUCCESS) {
        return ERROR;  // Read operation failed
    }

    // Check Data ReaDY 
    if( (buf[0] & ST1_STATUS_FLAG_DRDY) == 0 ){     // DRDY=0, data not ready
        return ERROR;
    }
    
    // Read IR threshold, temp threshold and data ready flags
    data->intStatus.irh = ((buf[1] & INT_STATUS_FLAG_IRH) > 0) ? true : false;
    data->intStatus.irl = ((buf[1] & INT_STATUS_FLAG_IRL) > 0) ? true : false;
    data->intStatus.tmph = ((buf[1] & INT_STATUS_FLAG_TMPH) > 0) ? true : false;
    data->intStatus.tmpl = ((buf[1] & INT_STATUS_FLAG_TMPL) > 0) ? true : false;
    data->intStatus.dr = ((buf[1] & INT_STATUS_FLAG_DR) > 0) ? true : false;
    
    // Extract IR sensor data
    data->ir = (int16_t)((buf[3] << 8) | buf[2]); // Combine IRL & IRH
    
    // Extract Temperature sensor data
    data->temperature = (int16_t)((buf[5] << 8) | buf[4]);  // Combine TMPL & TMPH

    // Extract Data Overrun status
    data->dor = ((buf[1] & ST2_STATUS_FLAG_DOR) > 0) ? true : false;
    
    return SUCCESS;    
}