softReset does not clear shadow registers

[t6z]

The softReset function only clears the SW_RST bit after initiating a soft reset. I believe it should reset all four shadow registers to zero. According to the datasheet:

Writing “1”will cause the part to reset, similar to power-up. It will clear all registers and also re-read OTP as part of its startup routine. The power on time is 10mS.

SparkFun_MMC5983MA_Magnetometer_Arduino_Library/src/SparkFun_MMC5983MA_Arduino_Library.cpp

Lines 281 to 295 in 8b22bc4

	bool SFE_MMC5983MA::softReset()
	{
	// Set the SW_RST bit to perform a software reset.
	// Do this using the shadow register. If we do it with setRegisterBit
	// (read-modify-write) we end up setting the reserved and BW_0 bits too as they
	// always seems to read as 1...? I don't know why.
	bool success = setShadowBit(INT_CTRL_1_REG, SW_RST);
	clearShadowBit(INT_CTRL_1_REG, SW_RST, false); // Clear the bit - in shadow memory only
	// The reset time is 10 msec. but we'll wait 15 msec. just in case.
	delay(15);
	return success;
	}

[t6z]

Updated softReset:

bool SFE_MMC5983MA::softReset()
{
    // Set the SW_RST bit to perform a software reset.
    // Do this using the shadow register. If we do it with setRegisterBit
    // (read-modify-write) we end up setting the reserved and BW_0 bits too as they
    // always seems to read as 1...? I don't know why.
    bool success = setShadowBit(INT_CTRL_1_REG, SW_RST);

    // A soft reset clears all registers
    clearShadowBit(INT_CTRL_0_REG, 0xFF, false);
    clearShadowBit(INT_CTRL_1_REG, 0xFF, false);
    clearShadowBit(INT_CTRL_2_REG, 0xFF, false);
    clearShadowBit(INT_CTRL_3_REG, 0xFF, false);

    // The reset time is 10 msec. but we'll wait 15 msec. just in case.
    delay(15);

    return success;
}

[PaulZC]

Hi Thomas (@t6z ),

Thank you for this.

Do you want to submit a Pull Request? (That way you get full credit.)

Best wishes,
Paul