User's Manual

SIM900B EVB User Guide
SIM900B-EVB_UGD_V1.01 6 14.04.2010
Figure 2： EVB BOTTOM view
A: SIM900B module interface
B: SIM card interface
C: headset interface
D: Download switch, turn on or off download function
E: VBAT switch, switch the voltage source from the adaptor or external battery
F: PWRKEY key, turn on or turn off SIM900B
G: buzzer
H: expand port, such as keypad port, main and debug serial port, display port
I: MAIN serial port for downloading, AT command transmiting, data exchanging
J: DEBUG serial port
K: hole for fixing the antenna
L: source adapter interface
M: light
N: hole for fixing the SIM900B
O: headphones interface