SIM808 GSM GPS GPRS Module + IPX SMA Antenna
|+10 4 % $28.13|
|+25 6 % $27.54|
|+50 8 % $26.96|
|+100 10 % $26.37|
|+300 12 % $25.78|
Three power input interface: DC044 interface and V_IN and a lithium battery interface.
Note that: The range of DC044 and the V_IN pin input voltage is 5-26V, when using the 5V as the power, be sure that the power supply can provide 2A current. The voltage range of Lithium battery input power is 3.5-4.2V.
Switch: It is used to open / close the input power supply for the module. When in use, confirm the toggle switched to the OPEN state (near the inside).
SMA antenna interface: there is a GSM antenna interface, a GPS antenna interface onboard and a BT antenna interface.
Start button: When the board is powered on, the LED (PWR) will light up. After a long press (about 2 second) this button the other three LEDs will light. And one of them starts to blink; this suggests that SIM808 is beginning to work now. When the power supply, GSM and GPS antenna and SIM card are connected to the module correctly, the LED will flash slowly (3 Second the 1 second light), which indicates that the module has been registered to the network, and you can make a call or do something else.
TTL serial interface: a TTL level interface. Notice that: The pin of VMCU is used to control the high level of TTL UART, in order to realize to match between 1.25V / 3.3V / 5V systems. For example, if you want to use the 51 MCU to connect this board, the pin of VMCU must be connected to the DC5V. And if use the STM32 MCU, the pin of VMCU must be connected to the DC3.3V. The pins of RXD is the RXD of SIM808 and the pins of TXD is the TXD of SIM808. The pin of V_IN can connect the Current, the function of this pin has the same function of DC044.
USB interface: This interface is just use to update the firmware of SIM808 module
Power supply: 5-26V
If power supply is less than 9V, you need 2A DC
Another channel power port is 3.5-4.2V, suitable lithium battery
Computer debugging USB - TTL