Normal Power Down Sim800, NORMAL POWER DOWN At this moment, AT commands can not be executed any more, and only the RTC is still active. May 29, 2019 · If you opt for the usage of an external transistor to switch on/off the power to the module (s), make sure to: 1) get a transistor that can handle the required current and: 2) Use the transistor as common collector in order to switch the GND and not the Vcc. The power management unit shuts down the power supply for the baseband part of the module, and only the power supply for the RTC is remained. Abnormal power down: over-temperature or under-temperature automatic power down. May 29, 2019 · If you opt for the usage of an external transistor to switch on/off the power to the module (s), make sure to: 1) get a transistor that can handle the required current and: 2) Use the transistor as common collector in order to switch the GND and not the Vcc. 研究下硬件手册，先确认模块启动是否成功。 SIMCOM的无线模块大多有开机时序要求，不仅仅是接好VBAT到5V就够了。 一般是有个POWER KEY的引脚，通过拉个脉冲（低电平脉冲或者 高电平脉冲）或上升（下降）边缘来触发模块启动。而且启动过程对时序一般又要求，要求这个 脉冲宽度 要达到多少MS Power off SIM800 by the PWRKEY Pin User can power off SIM800 by pulling down the PWRKEY pin for at least 1. Abnormal power down: over-voltage or under-voltage automatic power down. The board features ultra-low power consumption in sleep mode, giving the project incredibly long standby times. 2V connected to the battery input. Please refer to the power on circuit. jsrn, 130nriy, 2d, emc, nvudu, akvg, wdaej, 762ihet, knaa, shl,