DFRobot GSM / GPS shield with UNO init error Apologies, but I have little experience of Arduino etc. Has the &quot;Sim808 init error&quot; been resolved anywhere please? I have tried every example I can find including the ones on these StackExchange pages without success. I started with the GPS test code from:
https://wiki.dfrobot.com/SIM808_GPS_GPRS_GSM_Shield_SKU__TEL0097
Parancey, Marcello, Pooya and Arslan and others have suggested mods to this code so I have tried all of them I think - none working.
Then I watched this video:
https://www.youtube.com/watch?v=fN8fwX3KmsM
which appears to show the code below or similar:
/*
### Get GPS data
1. This example is used to test SIM808 GPS/GPRS/GSM Shield's reading GPS data.
2. Open the SIM808_GetGPS example or copy these code to your project
3. Download and dial the function switch to Arduino
4. open serial helper
4. Place it outside, waiting for a few minutes and then it will send GPS data to serial

create on 2016/09/23, version: 1.0
by jason

*/
#include &lt;DFRobot_sim808.h&gt;
#include &lt;SoftwareSerial.h&gt;

//#define PIN_TX    10
//#define PIN_RX    11
//SoftwareSerial mySerial(PIN_TX,PIN_RX);
//DFRobot_SIM808 sim808(&amp;mySerial);//Connect RX,TX,PWR,

DFRobot_SIM808 sim808(&amp;Serial);

void setup() {
  //mySerial.begin(9600);
  Serial.begin(9600);

  //******** Initialize sim808 module *************
  //while(!sim808.init()) { 
  while(!sim808.checkPowerUp()) {
      delay(1000);
      Serial.print(&quot;Sim808 init error\r\n&quot;);
  }

  //************* Turn on the GPS power************
  if( sim808.attachGPS())
      Serial.println(&quot;Open the GPS power success&quot;);
  else 
      Serial.println(&quot;Open the GPS power failure&quot;);
  
}

void loop() {
   //************** Get GPS data *******************
   if (sim808.getGPS()) {
    Serial.print(sim808.GPSdata.year);
    Serial.print(&quot;/&quot;);
    Serial.print(sim808.GPSdata.month);
    Serial.print(&quot;/&quot;);
    Serial.print(sim808.GPSdata.day);
    Serial.print(&quot; &quot;);
    Serial.print(sim808.GPSdata.hour);
    Serial.print(&quot;:&quot;);
    Serial.print(sim808.GPSdata.minute);
    Serial.print(&quot;:&quot;);
    Serial.print(sim808.GPSdata.second);
    Serial.print(&quot;:&quot;);
    Serial.println(sim808.GPSdata.centisecond);
    
    Serial.print(&quot;latitude :&quot;);
    Serial.println(sim808.GPSdata.lat,6);
    
    sim808.latitudeConverToDMS();
    Serial.print(&quot;latitude :&quot;);
    Serial.print(sim808.latDMS.degrees);
    Serial.print(&quot;\^&quot;);
    Serial.print(sim808.latDMS.minutes);
    Serial.print(&quot;\'&quot;);
    Serial.print(sim808.latDMS.seconeds,6);
    Serial.println(&quot;\&quot;&quot;);
    Serial.print(&quot;longitude :&quot;);
    Serial.println(sim808.GPSdata.lon,6);
    sim808.LongitudeConverToDMS();
    Serial.print(&quot;longitude :&quot;);
    Serial.print(sim808.longDMS.degrees);
    Serial.print(&quot;\^&quot;);
    Serial.print(sim808.longDMS.minutes);
    Serial.print(&quot;\'&quot;);
    Serial.print(sim808.longDMS.seconeds,6);
    Serial.println(&quot;\&quot;&quot;);
    
    Serial.print(&quot;speed_kph :&quot;);
    Serial.println(sim808.GPSdata.speed_kph);
    Serial.print(&quot;heading :&quot;);
    Serial.println(sim808.GPSdata.heading);

    //************* Turn off the GPS power ************
    sim808.detachGPS();
  }

}

I have mounted the DFRobot shield on a UNO and powered through the barrel connector with a 2_amp 5V stabilised power supply. The DFRobot shield shows a red LED power light and pressing reset flashes the blue LED next to it, but nothing else does anything - the serial monitor just repeats &quot;Sim808 init error&quot;. In the video the blue &quot;net&quot; LED flashes even before the SIM card is inserted, but my card does not flash. Do I return the board to Farnell and ask for my money back?
Any help greatly appreciated!
The dfrobot board has a weird boot button system that you need to follow to boot up the board. I spent ages attempting to get it to work before I finally achieved anything.
There is a blue led on the board that will flash continuously at different rates if the chip has been correctly powered and is searching for a mobile network.
I noticed that you commented it the while(!sim808.init()) line. This attempts to power the board on automatically, but I do remember something being funny about the implementation.
From doing a while load of research the dfrobot breakout board is not the best hardware implementation of this chip. Actually from memory there aren't any modules I have been able to find which satisfy all my requirements for a project. I'd recommend looking at all the documentation dfrobot provide on their website. Hopefully that should get you working.
Summary: it's an insanely fiddly process to get it working, but the boards are functional