user13265: I have a SIM800L GSM module like in this link, .
.
The problem is when I connect the GSM to my Arduino Uno the GSM turns on for a while and then turns off. I tried to connect it with a 9-volt battery and an LM7805 voltage regulator, but I have the same problem. Attached to the Arduino are an LM35 temperature sensor, two LEDs, a buzzer, an LCD, a GSM module, a gas sensor and a servo.
The other problem is with the servo. I tested the servo and it works fine but when the servo stops moving, it starts to shake. I do not know what the problem is.

user10394: You SIM800 module will pull 2Amps when its transmitting.  If your servo is also trying to overcome the inertia at the start of a movement it will pull 4+ times its normal running current.
A 9 volt battery will let you pull a couple of hundred milliamps.  So when the GSM transmits you system will shutdown.
You need a proper power supply or a battery pack that can put out these levels of peak current (3+Amps)

13265: <p>I have a SIM800L GSM module like in this link, <img src="https://i.stack.imgur.com/CkraF.png" alt="the GSM module I have">.</p>

<p><img src="https://i.stack.imgur.com/NFMBF.jpg" alt="this is the servo I have">.</p>

<p>The problem is when I connect the GSM to my Arduino Uno the GSM turns on for a while and then turns off. I tried to connect it with a 9-volt battery and an LM7805 voltage regulator, but I have the same problem. Attached to the Arduino are an LM35 temperature sensor, two LEDs, a buzzer, an LCD, a GSM module, a gas sensor and a servo.</p>

<p>The other problem is with the servo. I tested the servo and it works fine but when the servo stops moving, it starts to shake. I do not know what the problem is.</p>
 10394: <p>You SIM800 module will pull 2Amps when its transmitting.  If your servo is also trying to overcome the inertia at the start of a movement it will pull 4+ times its normal running current.</p>

<p>A 9 volt battery will let you pull a couple of hundred milliamps.  So when the GSM transmits you system will shutdown.</p>

<p>You need a proper power supply or a battery pack that can put out these levels of peak current (3+Amps)</p>
