C++ (Cpp) I2CSelectSlave示例

示例#1

文件： RTIMUHal.cpp 项目： suyashkumar/BME464_Tremor

bool RTIMUHal::HALRead(unsigned char slaveAddr, unsigned char length,
                    unsigned char *data, const char *errorMsg)
{
    int tries, result, total;
    unsigned char rxBuff[MAX_READ_LEN + 1];
    struct spi_ioc_transfer rdIOC;

    if (m_busIsI2C) {
        if (!I2CSelectSlave(slaveAddr, errorMsg))
            return false;

        total = 0;
        tries = 0;

        while ((total < length) && (tries < 5)) {
            result = read(m_I2C, data + total, length - total);

            if (result < 0) {
                if (strlen(errorMsg) > 0)
                    HAL_ERROR2("I2C read error from %d - %s\n", slaveAddr, errorMsg);
                return false;
            }

            total += result;

            if (total == length)
                break;

            delayMs(10);
            tries++;
        }

        if (total < length) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR2("I2C read from %d failed - %s\n", slaveAddr, errorMsg);
            return false;
        }
    } else {
        memset(&rdIOC, 0, sizeof(rdIOC));
        rdIOC.tx_buf = 0;
        rdIOC.rx_buf = (unsigned long) rxBuff;
        rdIOC.len = length;

        if (ioctl(m_SPI, SPI_IOC_MESSAGE(1), &rdIOC) < 0) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR1("SPI read error from - %s\n", errorMsg);
            return false;
        }
        memcpy(data, rxBuff, length);
    }
    return true;
}

示例#2

文件： RTIMUHal.cpp 项目： dnewmanca/RTIMULib

bool RTIMUHal::HALWrite(unsigned char slaveAddr, unsigned char regAddr,
                   unsigned char length, unsigned char const *data, const char *errorMsg)
{
    int result;
    unsigned char txBuff[MAX_WRITE_LEN + 1];
    char *ifType;

    if (m_busIsI2C) {
        if (!I2CSelectSlave(slaveAddr, errorMsg))
            return false;
        ifType = (char *)"I2C";
    } else {
        ifType = (char *)"SPI";
    }

    if (length == 0) {
        result = ifWrite(&regAddr, 1);

        if (result < 0) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR2("%s write of regAddr failed - %s\n", ifType, errorMsg);
            return false;
        } else if (result != 1) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR2("%s write of regAddr failed (nothing written) - %s\n", ifType, errorMsg);
            return false;
        }
    } else {
        txBuff[0] = regAddr;
        memcpy(txBuff + 1, data, length);

        result = ifWrite(txBuff, length + 1);

        if (result < 0) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR3("%s data write of %d bytes failed - %s\n", ifType, length, errorMsg);
            return false;
        } else if (result < (int)length) {
            if (strlen(errorMsg) > 0)
                HAL_ERROR4("%s data write of %d bytes failed, only %d written - %s\n", ifType, length, result, errorMsg);
            return false;
        }
    }
    return true;
}