SIM900A GSM/GPRS Module + Antenna Wireless Module:
– The onboard two set power supply interface VCC5 5V power supply, VCC4 interface, 3.5–4.5V power supply, optional power on self-starting (default) and control start
– The onboard SMA (default) and antenna interface, SIM900A interface reserved reset
– The size of the module is 49*50, all the new and original device
– Support 2, mobile phone 3,4G card
– The serial port circuit: support for 3.3V single chip microcomputer. TTL serial port support 3.3 and 5V single chip microcomputer.
– The SIM card circuit to increase the SMF05C ESD chip.
– Antenna circuit: guarantee short and straight, so as to ensure the signal strength.
– PCB display screen printing mark: each interface, convenient development two times, the SIM900/A hardware is completely follow the design when the design manual.
– Two power supply interface: VCC5, 5V DC above 1A. Computer 5V power supply can be early computer USB. DC long data circuit over larger recommended 5V1A. VCC4, 3.5–4.5V power supply, ibid., suitable for lithium battery.
– Control pin all leads.
– A TTL level, compatible with 3.3V and 5V.
The control interface of each pin description:
– GND – GND
– SIMR SIM900A RXD, TTL level, can not be directly connected to the 232 level
– SIMT SIM900A TXD, TTL level, can not be directly connected to the 232 level
– RST – SIM900A reset, active low