M35 User Manual Brandname: Quectel Category: Control Unit Total Pages: 86 Table of contents AboutTheDocument3Contents5TableIndex8FigureIndex9Introduction11SafetyInformation12ProductConcept13KeyFeatures14FunctionalDiagram16EvaluationBoard17ApplicationInterface18PinOfModule19OperatingModes24PowerSupply26PowerSaving34RtcBackup36SerialInterfaces38AudioInterfaces45PcmInterface50