板上资源： LM2576电源，MAX3232电平转换芯片，11.0592M有源晶振，ATMEGA128L，FM32256（铁电），滑槽式SIM卡座，40PZIF接插件，通信 模块支持CM320,TC35i，MC35i，MC39i，GTM900A/B等模块。 使用方法：1、不焊接M128和FM32256以及晶振，将桥接电阻R29,R30,R31焊上，就是标准串口无线MODEM，根据模块不同可以支持GPRS和CDMA，

降压电源 The LM2576 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving 3A load with excellent line and load regu

LM2576系统的稳压器是单片集成电路，能提供降压开关稳压器的各种功能，能驱动3A负载，有优异的线性和负载能力。-LM2576 stabilizer is a monolithic integrated circuit in the system, can provide various function of step-down switching voltage stabilizer, can drive 3 a load, has