SIM800L GSM/GPRS V2 Communication Module with Antenna Arduino
GSM wireless communication module with GPRS for a microSIM card in a set with an antenna.
It works in the 850, 900, 1800 and 1900MHz bands, thus supporting Irish GSM operators.
The module has the ability to transmit data and send and receive text messages and voice calls.
Built-in LED shows the current connection status to the GSM network.
Built-in voltage converter allows control by devices with 5V logic.
supply voltage 5V
GSM / GPRS QUAD BAND support (850, 900, 1800, 1900 MHz)
communication via the UART interface
IPX antenna connector (antenna with cable included)
microSIM card socket
built-in voltage converter
dimensions 40 mm x 30 mm
We would need to separate data transmission from powering the device.
Arduino digital pins, including those used for UART communication, can handle currents of max 40mA - see https://www.arduino.cc/en/reference/board - and this is absolutely enough for communication with your SIM800 board.
But SIM800 boards require much more power for GSM radio transmission and we are talking about 2A here. Each time the device is turned on and establishes a connection with GSM network, there is a power-demand spike and if your power supply isn't able to provide enough power, SIM800 will simply restart and will never log on to the GSM network.
So the solution is to use power source strong enough to provide these 2 amps.
This article describes the topic well and provides with detailed SIM800 power consumption for various operation modes. Although different SIM800 board is discussed, same power rules apply to V2 module.
Also pay special attention to your wiring. Commonly used DuPont jumper wires often become a weak point and you may need to use better cabling for SIM800 power pins.