I bought a GSM module, and I want to connect it with Arduino but I have a problem.

I linked GSM SIM800L with regular LM2596 12 V 2 VA I changed tension to 5 V, So far the GSM is working but if I connect TX_ARDUINO with RX_GSM the module enters in the loop of the restart.

The picture explains the montage.

Fritzing of LM2596, SIM800L and Arduino Uno

  • How are you providing power to arduino?
    – Vaibhav
    Apr 15, 2019 at 11:48
  • I connect Arduino with my pc. Apr 15, 2019 at 11:49
  • And your code...? Also, you shouldn't be using GSM in modern designs. Many carriers are turning off GSM services. You should be using (at least) an LTE modem.
    – Majenko
    Apr 15, 2019 at 12:06
  • You should separate the ground of external power supply and GND of arduino.
    – Vaibhav
    Apr 15, 2019 at 12:16
  • @Vaibhav How is that going to help matters? All that will do is break things further.
    – Majenko
    Apr 15, 2019 at 12:59

1 Answer 1


Arduino Sim800l

Follow this tutorial on how to connect your Sim800l with Arduino.

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