GSM Shield V2

[billcramer07]

Just purchased one of these. In order to get it to power up I must press and hold the power button for 1 to 3 seconds many times. Usually 8 to 10 times. Once it does power up it works ok. I am using a Arduino Uno and software serial on pins D7 and D8. I have tried power from both the usb and from the DC in jack (9 volts at 2 amps) on the UNO. It makes no difference how the board is powered. Also I have a sketch that toggles D9 from low to high for one second. This should also turn on the power but it dose not. As I said above, once I get the board to power on it finds the network and works well.

[Alex-w]

hi billcramer07:
is there anything burned?and can you send the sketch to me so that it can help me find the problem

[billcramer07]

I have checked the board carefully and I do not see anything burned. Also the solder connections look good. Here is part of the sketch that I tried that should power up the shield from the Arduino. I have also changed the delay time with no result. As I said before, once the board powers on it works ok and a short press of the power key will turn it off.

#include <SoftwareSerial.h>
SoftwareSerial SIM900(7, 8); // configure software serial port

void setup()
{
Serial.begin(19200);
SIM900.begin(19200);
pinMode(9,OUTPUT);
SIM900power();
delay(20000); // give time to log on to network.
}

void SIM900power() // software equivalent of pressing the GSM shield "power" button
{
digitalWrite(9, HIGH);
delay(1000); //tried different delay times here... up to 5 seconds
digitalWrite(9, LOW);
delay(5000);
}

[Alex-w]

hi billcramer07：
i will test the code