GSM/GPRS A6 Ai-Thinker

hello.
I want to make a simple call with the GSM/GPRS A6 (Ai-Thinker) module.

(module link:
http://www.inkocean.in/gprs-a6-module-sms-board-gsm-gprs-wireless-data-transmission-over-sim900a)

so I have connected this module to an arduino uno by the below wiring:

gnd-a6 to gnd-uno
Tx-TTL-a6 to pin 10 digital-uno
Rx-TTL-a6 to pin 11 digital-uno

also,I used a common 5 volt phone adapter to trigger the A6 module.

but not result has obtained and I couldn’t make a call (from module sim card or to it).
my code in the arduino IDE is as below:

#include <SoftwareSerial.h>
SoftwareSerial a6(10, 11); //Tx,Rx in A6

char phone_no[] = "a phone number";
 
void setup() {
  Serial.begin(115200);
  a6.begin(115200);
  delay(1000);
  Serial.println("AT");
  delay(100);
  Serial.print("ATD");
  Serial.println(phone_no);
  dalay(30000);
  Serial.println("ATH");
}

how do I do?
please notify me…

thanks a lot

Where do you ever send data to the a6? Where do you ever read anything from the a6?

this is my loop() method:

void loop(){ if(a6.available()){ Serial.write(a6.read()); }

if(Seial.available()){ a6.write(Serial.read()); } }

then I wrote "AT" in the arduino serial and press "send" button. but I received unreadable characters in the arduino serial and does not make a call with "ATD" command (ATDmyphonenumber) why? I saw a video in youtube. in there with only codes in the setup() method,he could make a call simply.

Added note: when I used from a usb-ttl converter for this module and I didnt use from arduino,the module worked correctly. why does not work with arduino uno?

but I received unreadable characters in the arduino serial

That suggests that the baud rate between the PC and the Arduino is not correct, or that the baud rate between the Arduino and the ESP is not correct.

PaulS: That suggests that the baud rate between the PC and the Arduino is not correct, or that the baud rate between the Arduino and the ESP is not correct.

No,I checked both baud rates (between PC and Arduino and between Arduino and A6 module). they are 115200. I could do the following works: -make a call (from sim card module and to it,also) - send sms from module. - receive sms in arduino serial monitor.

BUT MY MAIN PROBLEM IS that : characters in the serial monitor [Serial.write(a6.read())] are unreadable some time, so that I can not parse received message (text and phone number) observed in the serial monitor.

IMPORTANT NOTE: when I directly connect a6 module to PC (by ttl-usb cable) and use from terminal software (such as "Realterm" or "putty"),unreadable characters does not appear and EVERYTHING IS OK).

why this is happened with uno? please clarify me:(

No,I checked both baud rates (between PC and Arduino and between Arduino and A6 module). they are 115200.

For short periods of time, SoftwareSerial can work at 115200, IF you are transferring very small amounts of data. You are not, so you are making unrealistic demands on SoftwareSerial. A board with multiple hardware serial ports is in your future.