Never mind...that's what the DRDY_M pin is for!
BTW, there is a bug in the "Standard C platform-independent drivers" (lsm9ds1_STdC). When reading the Magnetometer data, you must read all the 6 data registers (0x28 to 0x2D) to clear DRDY_M.
/**
* @brief Magnetic sensor. The value is expressed as a 16-bit word in
* two’s complement.[get]
*
* @param ctx Read / write interface definitions.(ptr)
* @param buff Buffer that stores the data read.(ptr)
* @retval Interface status (MANDATORY: return 0 -> no Error).
*
*/
int32_t lsm9ds1_magnetic_raw_get(lsm9ds1_ctx_t *ctx, uint8_t *buff)
{
int32_t ret;
ret = lsm9ds1_read_reg(ctx, LSM9DS1_OUT_X_L_M, buff, 6);
return ret;
}
To read data in both the Accel/Gyro and the Magnetometer, b7 (RW) is set.
However, for the Magnetometer, you must also set b6 (MS) to auto-increment the register address. If you don't set this, you only read the first register 6 times, and DRDY_M is not cleared.
I cannot seem to find a control register in the Magnetometer that turns auto-increment on.
The code should look like:
/**
* @brief Magnetic sensor. The value is expressed as a 16-bit word in
* two’s complement.[get]
*
* @param ctx Read / write interface definitions.(ptr)
* @param buff Buffer that stores the data read.(ptr)
* @retval Interface status (MANDATORY: return 0 -> no Error).
*
*/
int32_t lsm9ds1_magnetic_raw_get(lsm9ds1_ctx_t *ctx, uint8_t *buff)
{
int32_t ret;
ret = lsm9ds1_read_reg(ctx, LSM9DS1_OUT_X_L_M + 0x40, buff, 6);
return ret;
}
