SIM900 SIM900A Module SMS Development Board GSM GPRS STM32 Wireless Data Transmission Exceeding TC35iItem NO.: SIM900A

SIM900 SIM900A Module

Power supply requirements for this module: 5V power supply, computer USB power supply can meet the requirements in the early stage of computer debugging. Because we added a large capacitor of 1000UF. Long term data transmission requires a high power consumption. It is recommended to use DC with a voltage of 1A or above, and the TTL level serial port is adaptive and compatible with 3.3V and 5V microcontrollers.

Introduction to SIM900A module:

Power supply requirements for this module: 5V power supply, computer USB power supply can meet the requirements in the early stage of computer debugging. Because we added a large capacitor of 1000UF. Long term data transmission requires a high power consumption. It is recommended to use DC with a voltage of 1A or above, and the TTL level serial port is adaptive and compatible with 3.3V and 5V microcontrollers. It can be directly connected to a microcontroller. The standby mode is around 80MA, and the sleep mode can be set to around 10MA with low power consumption. Computer debugging USB-232 and USB-TTL are both available, depending on each individual's accessory. Support SMS, data, MMS, internet access, etc. The reset pin can be pulled out to achieve on-site unmanned remote reset, with DTMF function to achieve remote control function. The advantage of the module is that it retains 232 ports and can monitor the execution of 51 low-end microcontrollers and module instructions during learning or development, which can quickly identify the cause and save development and learning time [Supports 2,3,4G mobile cards].

This module's TTL level is compatible with the 3.3V system, and the 5VTTL system requires a 232 control module.

Advantages of this module:

Serial port circuit: TVS and magnetic bead protection devices are used to protect the board from surges and high voltages.

SIM card circuit: Add SMF05C electrostatic discharge chip.

Antenna circuit: Ensure short and straight to ensure signal strength.

PCB display: Each interface is screen printed for easy secondary development, and the design fully follows the SIM900A hardware design manual.

One way 5V power supply interface: We have provided protection, even if it is reversed, it will not burn the board. The initial debugging of the computer requires USB power supply; We recommend DC with a power consumption of 1A or above for long-term data transmission.

One way TTL interface: supports 3.3V microcontroller and 5V microcontroller. That is to say, it supports Class 51 5V microcontroller and STM32 microcontroller.

Two antenna interfaces: SMA antenna interface and IPX MINI antenna interface (default not soldered).

One 232 level interface: That is to say, you can directly connect the module to the computer through a 232 USB serial port cable. You can also connect to a computer using USB TTL, depending on your personal accessory situation. There is no need to spend more money on accessories, which is the difference from other sellers.

Computer control module method:

In short, it means controlling the module by issuing instructions (AT instructions) through a serial port. Here are two commonly used ways to control the SIM900A module:

The first method is to convert the CP2102 USB to TTL module, which is available for sale in our store. The SIM900A module is debugged on the computer

The second method is to connect the module to the computer through a USB-232 serial port cable, and then connect it to a 5V power supply