Sim800L is a GSM/GPRS module. You can send a message, make a call, transfer data
though the GPRS or something else.
Overview
This SIM800l module has a set of TTL level serial interface, a set of power supply
interface. Besides, there are a set of antenna interface on this module.
The chip of SIM800L basic features
SIM800H is a complete Quad-band GSM/GPRS solution in a LGA type which can be embedded in the customer
Applications:
SIM800H support Quad-band 850/900/1800/1900MHz, it can transmit Voice, SMS and
data information with low power
Consumption:
With tiny size of 15.8*17.8*2.4 mm, it can fit into slim and compact demands of customer design. Featuring
Bluetooth, FM and Embedded AT, it allows total cost savings and fast time-to-market for customer applications.
General features
Quad-band 850/900/1800/1900MHz
GPRS multi-slot class 12/10
GPRS mobile station class B
Compliant to GSM phase 2/2+
- Class 4 (2 W @ 850/900MHz)
- Class 1 (1 W @ 1800/1900MHz)
Bluetooth: Compliant with 3.0+EDR
FM: 76~109MHz worldwide bands with 50 KHz tuning step
Dimensions: 15.8*17.8*2.4mm
Weight: 1.35g
Control via AT commands (3GPP TS 27.007, 27.005 And SIMCOM enhanced AT Commands)
Supply voltage range 3.4 ~ 4.4V
Low power consumption
Operation temperature:-40 ~85
Specifications for GPRS Data
GPRS class 12: Max. 85.6 kbps (downlink/uplink)
PBCCH support
Coding schemes CS 1, 2, 3, 4
PPP-stack
CSD up to 14.4 kbps
USSD
Non transparent mode
Specifications for SMS via GSM/GPRS
Point to point MO and MT
SMS cell broadcast
Text and PDU mode
Software features
0710 MUX protocol
Embedded TCP/UDP protocol
FTP/HTTP
MMS
E-MAIL
DTMF
Jamming Detection
Audio Record
TTS
Embedded AT (optional)
Specifications for voice
Triode
- Half rate (HR)
- Full rate (FR)
- Enhanced Full rate (EFR)
AMR
- Half rate (HR)
- Full rate (FR)
Hands-free operation
Echo suppression
Interfaces
88 LGA pads including:
Analog audio interface
RTC backup
Serial interface
Interface to external SIM 3V/1.8V
GSM Antenna pad
FM Antenna pad
Bluetooth Antenna pad
Compatibility
AT cellular command interface Certifications (Plan):
CE
GCF
FCC
ROHS
REACH
The module Basic features
 51 STM32 AVR MCU compatible
Prototype expand
The frequency is 850/900/ 1800/1900 MHz
  Power supply range: voltage is 4.6-5.2v; current is 1A or more (the current is very important).
Operating temperature range: -40 degrees C to +85 C
Communication interface: The TTL level serial interface compatible 2.85/3.3/5v MCU
LED: Two led, the Net led and the RING led.
Size:27*39mm
SIMCARD: micro SIMCARD holder
The description of pins:
The name of pins Description
5v Power interface Power the module
CONNECT TO DC5v
GND 
VDD TTL UART interface The TTL UART serial interface, you can connect the MCU like 51MCU or ARM or MSP430 directly. The pin of VDD is used to match voltage of the TTL.
SIM_TXD 
SIM_RXD 
GND if this pin is unused, keep open
RST RST the module, if this pin is unused, keep open
The name of pins Description
5v Power interface Power the module
CONNECT TO DC5v
GND 
VDD TTL UART interface The TTL UART serial interface, you can connect the MCU like 51MCU or ARM or MSP430 directly. The pin of VDD is used to match voltage of the TTL.
SIM_TXD 
SIM_RXD 
GND if this pin is unused, keep open
RST RST the module, if this pin is unused, keep open