Method query

src/DFPlayerMini_Fast.cpp:974–992

/ ! @brief Query the MP3 player for specific information. @param cmd The command/query ID. @param msb The payload/parameter MSB. @param lsb The payload/parameter LSB. @return Query response, -1 if error. */ /

 */
 /**************************************************************************/
int16_t DFPlayerMini_Fast::query(uint8_t cmd, uint8_t msb, uint8_t lsb)
{
	flush();

	sendStack.commandValue  = cmd;
	sendStack.feedbackValue = dfplayer::NO_FEEDBACK;
	sendStack.paramMSB = msb;
	sendStack.paramLSB = lsb;

	findChecksum(sendStack);
	sendData();
	timoutTimer.start();

	if (parseFeedback())
		if (recStack.commandValue != 0x40)
			return (recStack.paramMSB << 8) | recStack.paramLSB;

	return -1;
}