I am making a project using arduino uno & A7 gsm+gps+gprs module.my circuit connection is like this:

A7 UTXD -> arduino RX
A7 RTXD -> arduino TX
A7 GND -> arduino GND
A7 pwr_key -> A7 VCC5.0

When i make call from my mobile to A7,it's ok.But i cannot get call/msg from A7. Here is my code for making call:

char phone_no[]="phone_no";

void setup()

void loop()

What can i do now??? Please help me to fix it.I apologize for my poor english.

  • 1
    What is the output returned from your ATD command? Any debug messages, errors, etc? Commented Dec 7, 2017 at 13:42
  • Don't use delay() like that. Instead you need to actively parse the returned text from the modem to understand what is happening with it.
    – Majenko
    Commented Jan 24, 2018 at 11:34

1 Answer 1


Increase your second delay to 2000 (ie. 2 seconds).

  • 2
    Why? How that solve the problem? You just give a number, not an explanation.
    – user31481
    Commented Jan 24, 2018 at 10:34
  • 2
    Using delays in place of proper serial processing is not good advice. Increasing delays to try and combat a basic failing of the entire methodology is even worse advice.
    – Majenko
    Commented Jan 24, 2018 at 11:33

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