A7 AI Thinker [GPS]+GPRS+GSM

Using Arduino Sensors
#1

hey all,

Im really getting fed up with the A7 module.
I used to be able to get a GPSRD stream but now I can't even get an "OK" to my AT.

Please note that I am NOT using a shield but the regular module form Aliexpress.

So here's what I have tried:

I connect the U_RX and the U_TX to Serial 1 of my MEGA2560
I connect the GPS_TX to the RX of Serial 2 of my MEGA2560

I power on the module and press the PWR KEY for 2 seconds until the LED is lit.

Then I run this code:

void setup() {
  Serial.begin(115200);
  Serial1.begin(9600);
  Serial2.begin(9600);
  Serial.println("A7 Receive Test");

  Serial.print("Start");
  delay(10000);
  Serial1.write("AT");
  Serial.println("AT");
  delay(10000);
  Serial1.write("AT+GPS=1");
  Serial.println("GPS");
  delay(1000);
  Serial1.write("AT+GPRDS=1");
  Serial.println("GPRDS");
  delay(1000);
}

void loop() {
  if (Serial2.available()) {
    String b = Serial2.readString();
    Serial.println(b);
  }
  if (Serial1.available()) {
    String b = Serial1.readString();
    Serial.println(b);
  }
}

which gives me nothing..

Any help appreciated

#2

I've had problems like that with the A6 AliExpress module also. Sometimes it takes around 10 AT commands before I got the "OK" in the serial monitor. Also better results where achieved while powering up the A6 module, via its USB, and then, powering up the Arduino. Finally after trying out the A6lib, which I could not get to work, I switched back to AT commands, without a library, and had to change the baud rate back and forth, in the serial monitor, before receiving anything in the serial monitor.

I just ordered an A7 myself....

#3

How are you powering the ESP module.
Did you use a (470uF) buffer cap on the power pin.

Are you using a 1:2 voltage divider on the RX pin of the ESP.
The EP is a 3.3volt device, and is not 5volt (I/O) tolerant.
Leo..

#4