Cheap GSM module (SIM800) not connecting to the network

... And i don't see in your code any PIN manipulation, did you remove PIN from your SIM card? If you put it on a mobile, can you send a SMS?

Yes, I turned off the pin.

Αlso with three batteries in the row (+1.5V- +1.5V- +1.2V- = 4.2V), flashes 7 times quickly, pauses for 3 seconds and re-starts the same. Βut it does not work.

Which other library is compatible? I tried with others.

nksl: Yes, I turned off the pin.

Αlso with three batteries in the row (+1.5V- +1.5V- +1.2V- = 4.2V), flashes 7 times quickly, pauses for 3 seconds and re-starts the same. Βut it does not work.

Which other library is compatible? I tried with others.

I tried also very long with the SIM800L Module. My result is, the module itself doesnt work constant. I had tested about 10 Modules. The second I had works 2 days before it gets broken. My power supply has enough amp and the voltage I tested was between 3.8 and 5. In this case you can stop try. But... there is a newer module in the market: "SIM800L 2.0 with 5V" (had no time yet). I never tried it, but you can if you want. Just search on ebay for sim800l 2.0. Good luck. Please write us, if you have any further problems or success and how you did it

nksl: Yes, I turned off the pin.

Αlso with three batteries in the row (+1.5V- +1.5V- +1.2V- = 4.2V), flashes 7 times quickly, pauses for 3 seconds and re-starts the same. Βut it does not work.

Which other library is compatible? I tried with others.

Can you please measure Vin with a multimeter? That behavior seems power cycle. Also your library is very "high level", you don't know if error is when trying to connect, or when trying to send SMS. You need to put some Serial.println() to know exactly which AT command is failing...

I've use a SIM800L to send data once a day for more than a year without any issues (send HTTP data, not SMS)

geologic: Can you please measure Vin with a multimeter? That behavior seems power cycle. Also your library is very "high level", you don't know if error is when trying to connect, or when trying to send SMS. You need to put some Serial.println() to know exactly which AT command is failing...

I've use a SIM800L to send data once a day for more than a year without any issues (send HTTP data, not SMS)

Can you tell me please * where you bought your SIM800L Module? (Are you using the L Module? Or another one?) * How much Voltage and Amp are you using? * Can you post please your circuit diagram? Maybe with your piece of code?

I already ordered SIM800L V2.0. Υou will soon have news.

geologic, how your module flashes?
What you mean HTTP data? internet?

thanks

nksl: I already ordered SIM800L V2.0. Υou will soon have news.

geologic, how your module flashes? What you mean HTTP data? internet?

thanks

He means GPRS Webrequests. POST Requests or GET Requests for example

Kingside:
Can you tell me please

  • where you bought your SIM800L Module? (Are you using the L Module? Or another one?)
  • How much Voltage and Amp are you using?
  • Can you post please your circuit diagram? Maybe with your piece of code?
  1. I got it from ebay, i’m using SIM800L
  2. i use a LDO to feed 4,2V to module. In my test i never need more than 400mA, but i use it only in GPRS mode. It seems that to send SMS or voice calls it can reach 2A
  3. check post #42 http://forum.arduino.cc/index.php?topic=306159.msg2753689#msg2753689

resuming:

  • use a stable 4V @ 1A supply, better with a large capacitor on Vin (470uF). I use MCP1826 that can adjust Vout to 4.2V with 2 resistors;
  • RX / TX are not 5V tolerant, you need to keep them below 2,8V. Use some kind of level shifter (i use a diode and a resistor).
  • lots of things can go wrong (no network, wrong pin, bad voltage…). Use Serial.println in your code to see exactly in which AT command it fails

nksl: I already ordered SIM800L V2.0. Υou will soon have news.

geologic, how your module flashes? What you mean HTTP data? internet?

thanks

I use it in GPRS mode, it stablish a data link to send data to a cloud server. The difference (apart from de data sent instead of SMS or voice) is that consumes less (up to 500mA) than in SMS or voice mode (up to 2A)

It flashes about 500ms 10 times (adquiring network), and then flashes quickly (sending data). From your behavior it seems that it tries to adquire network and then power cycles, that is why i think it is a power issue. Please MEASURE VIN with a multimeter and check if goes below 3,6V. When transmitting it draws lots of mA, so maybe batteries could not maintain voltage. If it goes below 3.4 the module reboots

Thanks geologic. I'm sorry to go back to 'HTTP data' but I would like a clarification. I'm not familiar. A piece of information would help me look more. The data you send can be seen in your pc or on your mobile phone without being an e-mail or sms? Have you created a program that resembles an online image?

nksl:
Thanks geologic. I’m sorry to go back to ‘HTTP data’ but I would like a clarification. I’m not familiar. A piece of information would help me look more. The data you send can be seen in your pc or on your mobile phone without being an e-mail or sms? Have you created a program that resembles an online image?

Just google for “Webservice”. You can use php as a webservice. I think this is another part and has nothing to do with SIM800L

nksl: Thanks geologic. I'm sorry to go back to 'HTTP data' but I would like a clarification. I'm not familiar. A piece of information would help me look more. The data you send can be seen in your pc or on your mobile phone without being an e-mail or sms? Have you created a program that resembles an online image?

Yes, thats correct. I'm sending data from sensors to a webserver, so i can store it on a database. Later i can see the data through a webpage. In GPRS mode you send bytes of data (could be temperature from a sensor or a image from a camera) to a remote server. Usually in voice/SMS mode you send data to another cell phone.

Hello everyone! Glad to see I'm not the only one having trouble with the 800L.

I bought a module that looks like this: https://images-na.ssl-images-amazon.com/images/I/61lxdhTNSlL._SL1001_.jpg

Only the little curly wire thing (bottom left) was included - is this an antenna? If yes, where/how do I connect it, as just seems to be a piece of wire? Otherwise, will I have to buy an antenna like the one shown on the right of the image, or does it work without it? Are there any antenna specifications to consider?

I have not yet been able to connect to the network, so perhaps this is the issue. I will also try lowering the TX/RX voltage from 5V, even if it seems as if I can communicate well with the module. I will also raise the maximum current to 3A, even if I don't think I ever got close to the limit. I'll try to remember to update this post if I reach any conclusions!

PS: If anyone is having trouble with the PIN-code (despite using AT-CPIN=xxxx), I was able to disable the PIN requirement through the settings of an old Android smartphone. Of course, this is only valid when the PIN is not needed, and can probably be solved with a quick and easy AT command.

I worte a short piece on how I got mine to connect:

https://forum.arduino.cc/index.php?topic=496064.0

luhcforgh: Only the little curly wire thing (bottom left) was included - is this an antenna? If yes, where/how do I connect it, as just seems to be a piece of wire? Otherwise, will I have to buy an antenna like the one shown on the right of the image, or does it work without it? Are there any antenna specifications to consider?

Both are antennas, without one SIM800 cannot connect to network. The curly wire should be soldered to the top left hole (mine is labeled NET on the bottom). If you have the other antenna, just plug in on the u-fl connector (top left round connector).

luhcforgh: I have not yet been able to connect to the network, so perhaps this is the issue. I will also try lowering the TX/RX voltage from 5V, even if it seems as if I can communicate well with the module. I will also raise the maximum current to 3A, even if I don't think I ever got close to the limit. I'll try to remember to update this post if I reach any conclusions!

RX/TX are not 5V tolerant, do not connect more than 2,8V. Read previous posts to see how to create a level shifter.

SIM800L V2.0 5V

/* this library is writing by  Cristian Steib.
 *      steibkhriz@gmail.com
 *  Designed to work with the GSM Sim800l,maybe work with SIM900L
 *  
 *     This library use SoftwareSerial, you can define de RX and TX pin
 *     in the header "Sim800l.h" ,by default the pin is RX=10 TX=11..
 *     be sure that gnd is attached to arduino too. 
 *     You can also change the other preferred RESET_PIN
 *    
 *     Esta libreria usa SoftwareSerial, se pueden cambiar los pines de RX y TX
 *     en el archivo header, "Sim800l.h", por defecto los pines vienen configurado en
 *     RX=10 TX=11.  
 *     Tambien se puede cambiar el RESET_PIN por otro que prefiera
 *     
 *    PINOUT: 
 *        _____________________________
 *       |  ARDUINO UNO >>>   SIM800L  |
 *        -----------------------------
 *            GND      >>>   GND
 *        RX  10       >>>   TX    
 *        TX  11       >>>   RX
 *       RESET 2       >>>   RST 
 *                 
 *   POWER SOURCE 4.2V >>> VCC
 *
 *    Created on: April 20, 2016
 *        Author: Cristian Steib
 *        
 *
*/

#include <Sim800l.h>
#include <SoftwareSerial.h> //is necesary for the library!! 
Sim800l Sim800l;  //to declare the library
char* text;
char* number;
bool error; //to catch the response of sendSms


void setup(){
 Sim800l.begin(); // initializate the library. 
 text="Testing Sms";  //text for the message. 
 number="2926451386"; //change to a valid number.
 error=Sim800l.sendSms(number,text);
 // OR 
 //Sim800l.sendSms("+540111111111","the text go here")


}

void loop(){
 //do nothing
}

VCC 5V
GND GND
TX 10 or 11
RX 11 or 10
RESET 2

I could not connect. Failure to complete :frowning:

Do you see module led blinking? How do you power that module? Print "error" variable to see what is happening.

Can sim800L chip work in EDGE network?

mortenx: Can sim800L chip work in EDGE network?

It works only in EDGE network

EDGE is 2.5G and GPRS is 2G.

I am in Estonia and we have 3 networks Telia,Elisa and Tele2 ... and SIM800 chip sees only Tele2 network... why so ?