Hardware Design V1.01(091226)
Table Of Contents
- Contents
- Version history
- 1 Introduction
- 2 SIM900 Overview
- 3 Application Interface
- 3.1 SIM900 Pin Description
- 3.2 Operating Modes
- 3.3 Power Supply
- 3.4 Power Up and Power Down Scenarios
- 3.5 Power Saving
- 3.6 Summary of State Transitions (except SLEEP mode)
- 3.7 RTC Backup
- 3.8 Serial Interfaces
- 3.9 Audio Interfaces
- 3.10 SIM Card Interface
- 3.11 LCD Display Interface
- 3.12 Keypad Interface
- 3.13 ADC
- 3.14 Behaviors of the RI
- 3.15 Network Status Indication
- 3.16 General Purpose Input Output (GPIO)
- 3.17 External Reset
- 3.18 PWM
- 3.19 I2C Bus
- 4 Antenna Interface
- 5 Electrical, Reliability and Radio Characteristics
- 6 Mechanics
SIM900 Hardware Design
listed in following table:
Table
19: Working state of the NETLIGHT
State SIM900 function
Off SIM900 is not running
64ms On/ 800ms Off SIM900 does not find the network
64ms On/ 3000ms Off SIM900 find the network
64ms On/ 300ms Off GPRS communication
We provide a reference circuit for you, shown as following figure:
300R
4.7K
47K
VBAT
SIM900
MODULE
NETLIGHT
Figure 34: Reference circuit of NETLIGHT
3.16 General Purpose Input Output (GPIO)
SIM900 provides a limited number of General Purpose Input/Output signal pin. The output and input voltage level
of the GPIO can be set by AT command. For more details, please refer to document [1]
SIM900_HD_V1.01 26.12.2009
45