- Extra informatie
- Q & A
Let op: Kans is dat op deze goedkope module eerst nieuwe firmware geflashed moet worden om te kunnen gebruiken buiten Azië, ben je niet van uitproberen en experimenteren?, dan is deze module niet geschikt voor jou!
Note: Many SIM900A modules only work in Asia – see this site for details on how to modify them
The communication with this module is done through UART or RS232 Interface. The data is sent to the module or received from the module though UART interface.
The module is typically connected to +4.0V standard power supply. It can work on +4.5V regulated power and any higher voltage may damage the module. And the power source should be able to deliver a peak current of 2A. The UART interface is established as shown in figure. All you need to do is connect RXD of module to TXD of Arduino and TXD is connected to RXD of ARDUINO. The ground of controller and module must be connected for voltage reference. Here AUDIO IN is connected to MIC and AUDIO OUT is connected to a speaker or headset. And at last we need to connect a working GSM SIM card to the module. On powering the module the NETLIGHT LED will blink periodically to state successful connection.
After all connections are done,we need to write a program for the microcontroller to exchange data with module. Since data exchange sequence between controller and module is really complex we will use libraries prewritten for the module. You can download libraries for controller or module through their websites. Using these libraries makes the communication easy. All you need to do is download these libraries and call them in programs. Once the header file is included, you can use simple commands in the program to tell the controller to send or receive data. The controller sendsthe data to the module through UART Interface based on protocol setup in libraries. The module sends this data to another GSM user using cellular network. If the module receives any data from the cellular network (or another GSM user) it will transmit it to controller through UART serial communication.
This way we can use GSM900A module to establish cellular connection.
Pinout vanaf antenne: vcc, dtr, tx, rx, hoofdtelefoon, mic, rst, gnd
The primary difference between the SIM900A and the SIM800L is that this board doesn’t have Bluetooth and FM support. But the AT command set for both are identical which means we can use the same library!
The SIM900A breakout board has a 5V and a 4.2V version. Mine is the 5V version with the “V5.1” print near the VCC pin. This version can be powered by a 4.5 V to 5.5V source. There’s no information on what the 4.2V version looks like. I will update this post once the information is found.
SIM900A GSM MODULE Features:
Single supply voltage: 3.4V – 4.5V
Power saving mode: Typical power consumption in SLEEP mode is 1.5mA
Frequency bands:SIM900A Dual-band: EGSM900, DCS1800. The SIM900A can search the two frequency bands automatically. The frequency bands also can be set by AT command.
GSM class: Small MS
GPRS connectivity:GPRS multi-slot class 10 (default) , GPRS multi-slot class 8 (option)
Transmitting power: Class 4 (2W) at EGSM 900, Class 1 (1W) at DCS 1800
Operating Temperature: -30ºC to +80ºC
Storage Temperature: -5ºC to +90ºC
DATA GPRS: download transfer max is 85.6KBps, Upload transfer max 42.8KBps
Supports CSD, USSD, SMS, FAX
Supports MIC and Audio Input
Features keypad interface
Features display interface
Features Real Time Clock
Supports UART interface
Supports single SIM card
Firmware upgrade by debug port
Communication by using AT commands
Mobile Phone Accessories
|4 × 4 × 2 mm