SIM900A GSM Module with Antenna HW-353

SIM900A GSM Module with Antenna HW-353

Two power supply interfaces: VCC5, 5V DC above 1A.
Control pin all leads.
A TTL level, compatible with 3.3V and 5V.
The two-antenna interface, the default SMA straight head, connector for IPXmini antenna.
One way of speech interface, the way Mike interface.
The control interface of each pin description

GND – GND
SIMR SIM900A RXD, TTL level, cannot be directly connected to the 232 level
SIMT SIM900A TXD, TTL level, cannot be directly connected to the 232 level
RST – SIM900A reset, active low
VCC_MCU when the SIM900A module and 5V TTL level communication, this pin is connected to DC 5V; when the level of communication of SIM900A and 3.3V TTL, this pin is connected to DC 3.3V.
VCC5—-DC 5V input.
VCC4——DC3.5–4.5 input
Onboard Resources:

Serial port circuit(with protection)
Antenna interface circuit(SMA bend female port)
SIM card circuit(flip SIM slot)
4*3.5 fixture hole 4pcs