Hey i have a 3.7 V 18650 Li-Ion Batterie which Powers my SIM800L Module. My Arduino Mini gets 3.3 V from my Laptop. With an NPN Transistor i switch the LOW Side of my Module (GND). VCC of my power supply is connected to VCC of my module, GND is connected to Collector of my Transistor and Emitter with GND of my devices. I controll the Base to switch my SIM Module on and off.(And i also use a capacitor). But after some time of usage and testing my module doesnt connect the Mobile Network and when i remove the NPN Transistor it does connect so i think the NPN Transistor restricts some Voltage ... I looked up the internet and found that an P Mosfet to switch VCC instead LowSide in combination with NPN which pulls the Gate to GND when switch HIGH is a better variant to controll the SIM Module (switch on and off).
(I am a beginner btw)
Thank you
That is correct.
Here is a module
You could also use the power down AT command.
“AT+CPOWD=1”
There might be no need to add a transistor.
Did you try to put the module to sleep with a software command.
See this post.
Yeah i guess thats the best option
Yes i the answer before solved it i guess, just use the AT+CPOWD=1 command to turn power down, so no need to use a transistor.