Sim900a is not communicating with arduino uno

Projects Networking, Protocols, and Devices
1

I am trying to interface Sim900a with Arduino uno but i am not able to do that i connected RX and TX correctly. I connected two times 5v and ground for communication and between main pins I use 1000uf Capacitor then only it connect to network

My code is given below

#include <SoftwareSerial.h>

SoftwareSerial sim900(7, 8); // RX, TX (Arduino RX=7, TX=8)

void setup() {
  // Start Arduino Serial Monitor
  Serial.begin(9600);
  // Start SIM900 serial
  sim900.begin(9600);

  Serial.println("SIM900A Ready");
  Serial.println("Type AT commands below:");
  sim900.println("AT");
}

void loop() {
  // Forward data from Serial Monitor to SIM900A
  if (Serial.available()) {
    char c = Serial.read();
    sim900.write(c);
  }

  // Forward data from SIM900A to Serial Monitor
  if (sim900.available()) {
    char c = sim900.read();
    Serial.write(c);
  }
}
2

Post an annotated schematic showing exactly how you have wired it.

I connected two times 5v

Is that two wires or 10V?

What are the main pins?

What is the problem?

Post the schematic there are to many unknowns. Remember we cannot see your project.

3

It sounds like you are not following the wiring rules. Logic level shifters are required when connecting IO pins 5V microprocessors to IO pins on 3.3V modules.

For radio and LTE modules, an adequate power supply is also required (1 Ampere minimum for LTE). The Arduino Uno 5V output is not adequate.