Quectel M35 User Manual

GSM/GPRS Module Series
M35 User Manual
M35_User_Manual Confidential / Released 39 / 85
3.7.1. UART Port
3.7.1.1. The Features of UART Port
 Seven lines on UART interface.
 Contain data lines TXD and RXD, hardware flow control lines RTS and CTS, other control lines DTR,
DCD and RI.
 Used for AT command, GPRS data, etc. Multiplexing function is supported on the UART Port. So far
only the basic mode of multiplexing is available.
 Support the communication baud rates as the following:
300, 600, 1200, 2400, 4800, 9600, 14400, 19200, 28800, 38400, 57600 and 115200.
 The default setting is autobauding mode. Support the following baud rates for Autobauding function:
4800, 9600, 19200, 38400, 57600 and 115200.
 The module disables hardware flow control by default. AT command ―AT+IFC=2,2‖ is used to enable
hardware flow control.
After setting a fixed baud rate or autobauding, please send ―AT‖ string at that rate. The UART port is
ready when it responds ―OK‖.
Autobauding allows the module to detect the baud rate by receiving the string ―AT‖ or ―at‖ from the host or
PC automatically, which gives module flexibility without considering which baud rate is used by the host
controller. Autobauding is enabled by default. To take advantage of the autobauding mode, special
attention should be paid according to the following requirements:
1. Synchronization between DTE and DCE:
When DCE (the module) powers on with the autobauding enabled, it is recommended to wait 4 to 5
seconds before sending the first AT character. After receiving the ―OK‖ response, DTE and DCE are
correctly synchronized.
If the host controller needs URC in the mode of autobauding, it must be synchronized firstly. Otherwise
the URC will be discarded.
2. Restrictions on autobauding operation:
 The UART port has to be operated at 8 data bits, no parity and 1 stop bit (factory setting).
 Only the strings ―AT‖ or ―at‖ can be detected (neither ―At‖ nor ―aT‖).
 The Unsolicited Result Codes like ―RDY‖, ―+CFUN: 1‖ and ―+CPIN: READY‖ will not be indicated
when the module is turned on with autobauding enabled and not be synchronized.
 Any other Unsolicited Result Codes will be sent at the previous baud rate before the module detects
the new baud rate by receiving the first ―AT‖ or ―at‖ string. The DTE may receive unknown characters
after switching to new baud rate.
 It is not recommended to switch to autobauding from a fixed baud rate.

Quectel M35 Specifications

General

Brand	Quectel
Model	M35
Category	Control Unit
Language	English

Summary

About the Document

History

Document revision history and changes made over time.

Introduction

Safety Information

Essential safety precautions for operating the M35 module.

Product Concept

General Description

Overview of the M35 module's features and capabilities.

Directives and Standards

Compliance with FCC and other relevant regulations.

Key Features

Detailed list of the M35 module's technical features.

Functional Diagram

Block diagram illustrating the M35 module's main functional blocks.

Evaluation Board

Information about the M35 evaluation board for development.

Application Interface

Pin of Module

Details on the M35 module's pin assignment and layout.

Pin Description

Detailed description of each pin's function and characteristics.

Operating Modes

Summary of the different operating modes of the M35 module.

Power Supply

Information on power supply requirements and features.

Power On and Down Scenarios

Procedures for turning the module on, off, and restarting.

Power Saving

Methods for reducing module power consumption.

RTC Backup

Details on Real-Time Clock (RTC) backup power designs.

Serial Interfaces

Description of UART and Debug ports.

Audio Interfaces

Details on analog input and output channels for audio.

PCM Interface

Configuration and usage of the Pulse-Code Modulation interface.

SIM Card Interfaces

Information on accessing SIM cards via the module's interfaces.

Behaviors of The RI

Explanation of the Ring Indicator (RI) pin's behavior.

Network Status Indication

How the NETLIGHT pin indicates network status.

Operating Status Indication

Indication of module status via the STATUS pin.

Antenna Interface

Pin Definition of the RF_ANT

Definition of the RF antenna pin and associated ground pins.

RF Reference Design

Reference design for connecting the RF antenna to the module.

RF Output Power

Specifications for the module's RF output power.

RF Receiving Sensitivity

Specifications for the module's RF receiving sensitivity.

Operating Frequencies

List of operating frequencies for GSM bands.

Antenna Requirement

Requirements for GSM antennas and cables.

RF Cable Soldering

Guidelines for correctly soldering RF cables to the module.

Electrical, Reliability and Radio Characteristics

Absolute Maximum Ratings

Maximum limits for voltage and current parameters.

Operating Temperature

Specifies the normal and restricted operating temperature ranges.

Power Supply Ratings

Detailed power supply voltage and current ratings.

Current Consumption

Values of current consumption in various operating modes.

Electro-static Discharge

Information on ESD protection and tested values.

Mechanical Dimensions

Mechanical Dimensions of Module

Physical dimensions of the M35 module.

Recommended Footprint

Recommended PCB footprint for module placement.

Top View of the Module

Visual representation of the module's top side.

Bottom View of the Module

Visual representation of the module's bottom side.

Storage and Manufacturing

Storage

Guidelines for storing the M35 module safely.

Soldering

Recommendations for soldering the module onto a PCB.

Packaging

Information on how the modules are packaged.

Tape and Reel Packaging

Details on tape and reel packaging specifications.

Appendix A Reference

Related Documents

List of related documents for further information.

Terms and Abbreviations

ADC to DTX

List of terms and abbreviations from ADC to DTX.

EFR to MS

List of terms and abbreviations from EFR to MS.

MT to VILmin

List of terms and abbreviations from MT to VILmin.

VOHmax to VOLmin

List of terms and abbreviations from VOHmax to VOLmin.

Phonebook Abbreviations

List of abbreviations related to phonebook functions.

Appendix B GPRS Coding Scheme

Description of Different Coding Schemes

Details on GPRS coding schemes CS-1 to CS-4.

Appendix C GPRS Multi-slot Class

GPRS Multi-slot Classes

Description of GPRS multi-slot classes and their configurations.