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Using Arduino => Project Guidance => Topic started by: kuruki on Mar 05, 2015, 09:50 pm

Title: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 05, 2015, 09:50 pm
Hi, i recently received a cheap (around 12$) GSM module, namely the SIM800. It is the same one used by Adafruit Fona (https://learn.adafruit.com/adafruit-fona-mini-gsm-gprs-cellular-phone-module/wiring-to-usb). I can communicate with it through the serial port, sending AT commands etc. However, it doesn't seem to want to connect to the cellular network, even if it should (since Adafruit uses it and the bands seemed compatible, right?).
Specifically, i am following the instructions here (https://learn.adafruit.com/adafruit-fona-mini-gsm-gprs-cellular-phone-module/wiring-to-usb) and everything seems normal such as the module name and revision or the SIM card number. However, when I send the crucial AT+COPS? command, i get back +COPS: 0 instead of something like +COPS: 0,0,"Carrier_name".


Any ideas on what could be going wrong? I just hate to think that i bought yet another GSM module just for it not to be compatible in Europe (i live in Sweden and my carrier is Comviq).

The GSM module I have is this:
(http://i.lnwfile.com/_/i/_raw/sm/ut/md.jpg)


Thanks in advance! :)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: AndreasVan on Mar 05, 2015, 11:39 pm
Hade samma problem här det var pin-koden som krånglade. Har du provat med deaktiverat pin-kod ?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 06, 2015, 12:05 am
Hade samma problem här det var pin-koden som krånglade. Har du provat med deaktiverat pin-kod ?
Well i don't have any PIN code activated right now. When i put the sim card into my phone, it boots up and gets a network signal without any prompt for pin or password. Should i do anything else? I saw there were some AT PIN commands but i never bothered to go through them since there is no PIN active at the moment.

P.S. I live in Sweden, i'm not Swedish, I understand the language though. :smiley-mr-green:
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: AndreasVan on Mar 06, 2015, 12:24 am
Ok ! Where do you come from ?

Anyway, its important that you have a 2G sim-card; 3G or 4G doesn't work.
"Comviq kontant" is working fine for me.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 06, 2015, 12:30 am
Hmm, well what does a "2G sim card" mean? Does it apply for us? Mine is not a "data" (3G/4G) sim card if that's what you're asking. The one I have should be 2G + 3G (+ 4G :P ) since it can operate in both of the networks. (i use it for every day normal phone calls, so i know it works and has enough credit in it).

I'm from Greece, studying in Gothenburg. :)

PS. It's not the PIN.

Quote
AT+CPIN?
+CPIN: READY
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: AndreasVan on Mar 06, 2015, 10:52 pm
Hmm, well what does a "2G sim card" mean?
2G Sim Cards means  "Data SIM only". Its the best way is to call "Kundtjänst" to see if your sim is working in 2G network.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 06, 2015, 11:45 pm
To my knowledge, they don't even sell "2G only" sim cards any more. I tried the "AT+COPS=?" command yesterday and it printed among some other stuff the TELIA network. This is my only indication so far that the GSM module finally "sees something"! So as a last resort i went and bought a TELIA sim card. However I haven't tried it yet. Hopefully tomorrow. Will keep you posted! :)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: stoutfiles on Mar 06, 2015, 11:55 pm
You will need to know the APN your SIM uses to connect.  I use this particular one:

https://www.roamline.com



Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 07, 2015, 12:39 pm
You will need to know the APN your SIM uses to connect.  I use this particular one:
https://www.roamline.com
The tutorials i've found online for the specific module don't mention anything like this. Why would i need a special (international) SIM card, since this module is for the simple GSM bands that we have here?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 08, 2015, 11:56 am
I tried the new SIM card of a different carrier. I disabled the SIM card's PIN number and made sure there's enough credit to make calls etc (tried it first with my phone), so the SIM card generally works.

Let's verify there's no PIN.
Quote
AT+CPIN?
+CPIN: READY

OK
Ok, let's check the network. The AT+COPS? command now returns something much better. (before it'd reply with 0)
Quote
AT+COPS?
+COPS: 1

OK
From the documentation "1" stands for "Operator available".
Ok, that's good, let's check the signal now, which before was 0,0.

Quote
AT+CSQ
+CSQ: 21,0

OK
Very nice!

Let's turn the verbose errors, set the text mode on and try to send an sms.
Quote
AT+CMEE=2
OK
AT+CMGF=1
OK
AT+CMGS="00467692*****"
> test
>
+CMS ERROR: unknown
Aaaaaand nothing.... :(

Let's try to make a phone call. Maybe that works.
Quote
ATD76922****;
OK

NO CARRIER
Nope. :/
So the behavior is definitely different than before, seems better, but still. Before i would get a "NO DIALTONE" reply when i'd try to make a phone call and generally i couldn't even get so far into the sending message sequence.

Any help would be greatly appreciated. Is there any chance that I have a "wrong" SIM card? This is just a normal SIM card that can make/receive calls and messages in all the standard networks (2G, 3G, 4G).
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: dannable on Mar 08, 2015, 12:56 pm
Try prefixing the numbers you are texting / calling with the international code - +46 for Sweden. You may need to drop the leading zero from the operation / location code.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: AndreasVan on Mar 08, 2015, 02:56 pm
Let's verify there's no PIN.
AT+CMGS="00467692*****"
> test
>
+CMS ERROR: unknown
Try ++467692....


ATD769220230;
OK

NO CARRIER
Here you was missing the "0" it has to be 0769220230
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 08, 2015, 04:45 pm
I still get a "NO CARRIER" reply. It doesn't really matter what number i put there, since it doesn't reach the stage where the validity of the number is checked. (it just checks if the given argument after the at-command, is less digits than the upper limit)

Quote
ATD076922****;

OK

NO CARRIER
ATD++4676922****;

+CME ERROR: operation not allowed
ATD+4676922****;

OK

NO CARRIER

ATD+46076922****;

+CME ERROR: operation not allowed

For example
Quote
ATD12345;

OK

NO CARRIER
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Clemens on Mar 28, 2015, 12:49 am
What power connection do you have? I had some trouble with at least one (other) GPRS board that was connected to the Arduino's power rail directly. I got some responses to AT commands--so I thought it is working--but power was not sufficient for sending. This is not nice for debugging because "something is working", and often you do not think about power because power is a 1/0 thing in the most cases.

Seems like you have this item: http://www.ebay.de/itm/SIM800L-GPRS-TCP-IP-Module-Pop-up-Card-Slot-GSM-Card-microSIM-2PCS-Antenna-NEU-/181627843185

Quote
Operating voltage: 3.7 - 4.2V (peak current 2A, please be prepared to handle)
I used a 3.7V Lipo to got it running.

Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Clemens on Mar 28, 2015, 12:57 am
Hmm, this is interesting: https://www.youtube.com/watch?v=-manXBQFy3Y seems like using Arduino's 5V with a power dropping diode and it is nevertheless working.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Mar 28, 2015, 06:39 am
What power connection do you have?
I have it connected to a 4xAA battery pack with a regulator between them to drop down the voltage to around 4.2 V. I believe it should be giving enough current to work properly. :/
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Clemens on Mar 28, 2015, 11:56 am
You may try out this AT commands:
http://m2msupport.net/m2msupport/sms-at-commands/

There are a lot of other debug examples. Don't know it is helping you.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nikola1010 on Apr 14, 2015, 12:20 am
I have the same problem but also every once and then SIM800L outputs on it's own:

Code: [Select]

+CFUN: 1

+CPIN: READY

Call Ready

SMS Ready

Call Ready

SMS Ready


What could be the issue?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Apr 14, 2015, 09:47 am
I'd get those "Call Ready" and "SMS ready" too sometimes. Glad to know I'm not the only one with the problem. Which country did you try this in if I may ask?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nikola1010 on Apr 14, 2015, 04:04 pm
Croatia.

I asked my ebay seller to tell me if they are locked on China network or something, but didn't get any useful information.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nickiskr on Jun 23, 2015, 01:55 pm
I have the same problem.
The module is rebooted and is not registered on the network with newer SIMcard 4G.
Sometimes it works without any problems with old SIMcard 3G.
I'm from Russia. Sim800L.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: tomsoft on Jul 09, 2015, 03:44 pm
I got one of these to.

What I see, is that I can not dial , I always have the "no network" error

but:
- I can send and receive SMS
- I have the "ring" signal if I call the SIM


I use a prepaid Orange Sim card for france

Not sure if this hep, would be happy to get more info on this....
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: oscardec on Jul 29, 2015, 04:32 pm
Hello.

Try changing the position of your sim card.

This is a very common error.

Best regards.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: kuruki on Jul 29, 2015, 05:50 pm
That was definitely not it, since the SIM card was getting recognized by the module.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: devinger on Jul 30, 2015, 08:42 pm
I also have this problem with a different breakout board. The weird thing is, when I put in a different sim, the module suddenly does work.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: karamelo on Aug 04, 2015, 12:18 am
Well I've received exactly the same module as the youtube video, but looking at the data sheet, it specifically says that the power input should be around 4V-2A, just bought a adjustable DC-DC converter with an LM2596:

http://www.aliexpress.com/item/1pcs-LM2596-LM2596S-DC-DC-3-40V-adjustable-step-down-power-Supply-module-NEW/1116954291.html

The data sheet also mentions that the data lines should have a max voltage of 2.8V. And a suggested circuit for adapting from 3.3V to 2.8V appears on page 31 of the hardware design guide:

http://simcomm2m.com/UploadFile/TechnicalFile/SIM800L_Hardware_Design_V1.00.pdf

So I think that connecting this directly to an arduino possibly isn't the right choice... The power supply doesn't provide enough current and data lines need some circuitry in order to work.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: theanat2010 on Nov 06, 2015, 03:31 pm
I have the same problem in registration the sim to the network the AT command are working properly until I use AT+cmgs=......
ctrl+z ...send amsg then it return error


I use orange ..jordan network
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Egad on Dec 31, 2015, 10:16 am
I have been working on a home alarm project for a while. I think I can answer some of the questions here on this thread...

Through my work, I have been using this AT-Command manual for Sim800 - https://www.adafruit.com/datasheets/sim800_series_at_command_manual_v1.01.pdf (https://www.adafruit.com/datasheets/sim800_series_at_command_manual_v1.01.pdf)


I have the same problem but also every once and then SIM800L outputs on it's own:

Code: [Select]

+CFUN: 1

+CPIN: READY

Call Ready

SMS Ready

Call Ready

SMS Ready


What could be the issue?

For me, this happens when I send an AT-command before the module gets contact with the network. The Call/SMS Ready are then sent as the module connects to the network.

When I wait for the module to connect before I send my first AT-command, I do not get such messages.





Well I've received exactly the same module as the youtube video, but looking at the data sheet, it specifically says that the power input should be around 4V-2A, just bought a adjustable DC-DC converter with an LM2596:

http://www.aliexpress.com/item/1pcs-LM2596-LM2596S-DC-DC-3-40V-adjustable-step-down-power-Supply-module-NEW/1116954291.html

The data sheet also mentions that the data lines should have a max voltage of 2.8V. And a suggested circuit for adapting from 3.3V to 2.8V appears on page 31 of the hardware design guide:

http://simcomm2m.com/UploadFile/TechnicalFile/SIM800L_Hardware_Design_V1.00.pdf

So I think that connecting this directly to an arduino possibly isn't the right choice... The power supply doesn't provide enough current and data lines need some circuitry in order to work.
I fixed the RX/TX issue by putting a zener to lower the arduino TX signal. Like here: http://wiki.groundlab.cc/doku.php?id=microcontrollersgsm


The other line is good to go; the arduino senses 2.8V signals.

I also got my 4V power source by lowering the arduino 5V with a zener.




I have the same problem in registration the sim to the network the AT command are working properly until I use AT+cmgs=......
ctrl+z ...send amsg then it return error


I use orange ..jordan network
I do not really understand, but if you communicate directly with the module (through terminal) there is no way (if there is, I have missed it) to send <ctrl+z> as this is char no.26 (GSM charset)
My workaround was this:   (a slight modification of the SoftwareSerial example)
Code: [Select]

void loop() // run over and over
{
  if (mySerial.available())
    Serial.write(mySerial.read());
  if (Serial.available()){
    char c = (char)Serial.read();
    if(c == '#')
        mySerial.write((char)26);
    else
        mySerial.write(c);
  }
}


Hope this will help you!

//Egad
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: hasard on Jan 10, 2016, 06:37 pm
Don't forget ; character if you try to call:
ATD+7916XXXXXXX;
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: simonsmart99 on Jan 20, 2016, 01:10 pm


Hi All

I have exactly the same problem with a similar module:

http://www.ebay.co.uk/itm/New-SIM800L-GPRS-GSM-Module-SIM-Board-Quadband-L-shape-Antenna-for-MCU-Arduino-/161698611153?hash=item25a5fcffd1

I have a 2Amp 5v regulated supply powering the unit, so no power problems here.

Here is the response I get when trying to register:

AT+COPS=?
+COPS: (2,"vodafone","voda UK","23415"),(3,"T-Mobile","TMO UK","23430"),(3,"O2","O2 -UK","23410"),,(0-4),(0-2)

OK

AT+COPS?
+COPS: 1

OK


And when I try to register to the Vodafone network manually:
 
AT+COPS=1,0,"vodafone"
ERROR


So it seems very much as if the module is unable to connect to UK networks.

ANY INPUT WOULD BE GREATLY APPRECIATED.

Kind regards
Simon


Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: OleW on Feb 01, 2016, 08:25 pm
Hi,

I have been working some years with the SIM900 which is similar to SIM800 (got one of
these too but haven't tested) and the problem with not registering to the network depends on the network operator.

The SIM modems (800 /900) does NOT support 3G/4G only 2G. So if the network operator request to use the 3G network for startup (this is determid by the operator when programming the SIM card) it will not be possible to register.

I have tested with many different SIM cards around the world and this seems to be the logical explanation (I have also contacted SIMCorp to see if any commands could be use to change the startup and force the modem to regsiter). If you select a network operator the use 2G for start up (I have seen
af patterne that pre-paid SIM card often work - guess they are setup to be used for any mobile device).
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: juan3211 on Mar 17, 2016, 07:16 pm
Hi,

Does anybody use this kind of modules with a power supply of 5V and a simple DIODE ???? How long ?

Thanks a lot.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 04, 2016, 08:46 pm
Don't use a diode unless your power supply is very stable.
i've used that module with a external power supply regulated to 4.95V with a diode to down voltage to 4.25V. Then i replaced the power supply for a pack of batteries (5.08V), after that i got strange behavior, sometimes SIM800 didn´t send any messages. I figured that at 5.08V, the voltage on the SIM800 was 4.35V that leeds to OVERVOLTAGE warnings. Better is to use a LDO or some external power very stable, around 4.2V
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: juan3211 on Apr 05, 2016, 12:28 am
Don't use a diode unless your power supply is very stable.
i've used that module with a external power supply regulated to 4.95V with a diode to down voltage to 4.25V. Then i replaced the power supply for a pack of batteries (5.08V), after that i got strange behavior, sometimes SIM800 didn´t send any messages. I figured that at 5.08V, the voltage on the SIM800 was 4.35V that leeds to OVERVOLTAGE warnings. Better is to use a LDO or some external power very stable, around 4.2V
Could be the real problem the fact that batteries can't supply the 2A peak that SIM800L could need sometimes ?

Regards,
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 05, 2016, 11:17 am
Not the case. as soon i replaced the diode for a 4V LDO, everything went to normal.

Despites specs saying Sim800 can consume up to 2A current, in my tests i never measured more than 350mA. I'm using a regular multimeter and only use GPRS functionality, never tested with voice or SMS.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Clemens on Apr 05, 2016, 09:44 pm
It's not only about the Vcc power, pins need also a voltage divider. The serial port characteristic of the spec says 2.8 V max:

see p. 31 http://www.seeedstudio.com/wiki/images/4/46/SIM800L_Hardware_Design_V1.00.pdf
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: juan3211 on Apr 05, 2016, 10:56 pm
It's not only about the Vcc power, pins need also a voltage divider. The serial port characteristic of the spec says 2.8 V max:

see p. 31 http://www.seeedstudio.com/wiki/images/4/46/SIM800L_Hardware_Design_V1.00.pdf
Yes, it could be. But sometimes these modules came with a voltage "translator" and you can use a 5V signals, but you have to be really carerful with power voltage, not to burn it.

May be a diode is faster o slower than others? (i don't know about this kind of problem)

Regards,
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 06, 2016, 09:15 am
Yes, it could be. But sometimes these modules came with a voltage "translator" and you can use a 5V signals, but you have to be really carerful with power voltage, not to burn it.
Yes, mine is 5v tolerant, no need for level shifting

Quote
Maybe a diode is faster o slower than others? (i don't know about this kind of problem)

Regards,
for supplying power i think it's irrelevant, just use one rated for 2A or higher
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Andrea1970 on Apr 15, 2016, 06:08 pm
Today i received the same module with same problem. Red LED blink fast and typing AT+COPS? the answer is AT+COPS:0.
I powered the module with 3 D Cell with a DIODE, the voltage supply is about 3.9V=(4.5-0.6)V
The bheaviour are strange! Sometimes the module accept commands sometimes not! Can someone an give me tricks?
I think that i threw my money  away, not is the first time! In the past i tested more GSM module.
With TELIT i never had problems, but when i started to test cheapest SIMCOM (assembled by various/unknow Chinese company) it was a Hell! 900 ok, 900A don't run in Europe, 800L with direct connection (like reported by vendors) to 5Vcc of Arduino board (burn various LM1111). 
 
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 18, 2016, 12:57 pm
Are you sure you are powering at 3,9V? Measure it with a voltimeter when SIM800 is ON, i guess your batteries cannot mantain a steady 4,5V


I had one working for a month and suddenly it stops working. I was powering it with 4V but RX/TX lines were connected directly to 5V arduino ports.
I replaced by a spare one but this time add a level shiftter between arduino and RX to lower the signal to 2,8V. It is running now for 2 weeks without a fault.

For my experience, i advise:
1) Power SIM800 with a 4V LDO. Use a diode only if your input is very stable
2) Keep RX/TX lines below 2,8V
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: elik745i on May 11, 2016, 02:20 pm
Are you sure you are powering at 3,9V? Measure it with a voltimeter when SIM800 is ON, i guess your batteries cannot mantain a steady 4,5V


I had one working for a month and suddenly it stops working. I was powering it with 4V but RX/TX lines were connected directly to 5V arduino ports.
I replaced by a spare one but this time add a level shiftter between arduino and RX to lower the signal to 2,8V. It is running now for 2 weeks without a fault.

For my experience, i advise:
1) Power SIM800 with a 4V LDO. Use a diode only if your input is very stable
2) Keep RX/TX lines below 2,8V

Can you please attach circuit diagram. I also experience such problems, Used one SIM800L for a month, then is stopped registering in the network, when I pull TX line from SIM800L, restart the module it registers in the network, then put TX back and it works, then if I reset the Arduino, it resets the SIM800L and can't register in the network again. Looks like problem is with module's serial ports, will test another one with voltage dividers...

Strange thing is no matter it's registered or no, it responds and communicates with Arduino OK, displays found networks, but when I send command to connect to the carrier AT+COPS=0,2,"40001" for example it responds ERROR....why?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: zancos on May 11, 2016, 07:36 pm
I had same problem with SIM800 module and the problem was the supply current.

I recommend:

1. Test SIM card in your mobile in order to verify if it is working properly (maybe the SIM card is damaged)
2. Try to supply the SIM800 with an stable source 4,1V@3amp. Its important to know if your problem is a supply current problem to discard any other issues.

In my case I used a DC-DC converter from 12V@2.5amp to 4,1@2.5amp and now it works properly. If the module is connected to a source without enought current, the SIM800 module will reponse to AT commands but all of these commands relationated with the SIM will not work.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 13, 2016, 04:35 pm
Here is a sketch of my circuit.
Left side is the LDO that outputs 4V
R3 and R4 are a voltage divider to provide 2,8V. That voltage feeds the level shifter (1n4148 with 4,7k).
Only RX line needs protection, since TX will be always below arduino 5V limit.
For clarity i didn't connect TX ou RESET lines.

When testing, check SIM800 RX and TX pins, if they are around 2,8V everything is ok.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: elik745i on Jul 08, 2016, 06:05 pm
The problem was, I think, faulty module, module got damaged most probably as I never used voltage divider between arduino and SIM800, after replacing module and using simple voltage divider new module working like a charm!

DO NOT USE THIS MODULE WITHOUT RX AND TX VOLTAGE DIVIDER!!!
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: freman13 on Sep 25, 2016, 07:24 am
I just got SIM800L myself, and have same problems with connecting to network. While SIM900 worked like charm this one is a bit stubborn.

I receive AT commands related with SIM as well, but I can't send SMS for example. Maybe it is not registered to network... Does this module needs to register to network manually every time?

Also, you mention Rx/Tx voltage dividers and zeners as must, but I've seen many circuits out there and demonstrated on Youtube that didn't use any of those and still works perfectly fine.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: juan3211 on Sep 25, 2016, 01:57 pm
Hi, an experiencie of 10 minutes: a Li-Ion battery to power SIM800L (4.2V) and a Arduino board compatible with 3.3V power, so RX and TX with 3.3V logic.

With this config I hasn't got any problems in that 10 minutes.

Regards
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: jule on Sep 26, 2016, 04:27 pm
Hi, does anybody solved the topic title problem?

Im using a SIM800L module. (Iv tried a second SIM800L but the second module is doing the same)
and
..a laboratory power supply with 3AMPS and tried 3.8V up to 4.4V -> everything OK.
..an FTDI adapter with 3.3V TTL TX RX signals -> SIM800L communicates well with PC.
..Arduino with TTL 5V to TTL 3.3V curcuit. -> Module communicates well.

Im using two different provider SIM cards. DREI and YESSS (both from Austria -> Im from Austria :)
With DREI SIM card (1 Year old - for 3G and 4G) it is registering in network automatically
with AT+CSQ it says +CSQ: 30,0 - and with AT+COPS=? it shows the available providers and marks the correct provider with 2 (means than it has registered to this network) -> ->
-> so everything seems OK
BUT it does not send SMS every try. (Im doing it right because it worked two times from tens of tries).

Question: A timing problem? Must the commands be sent to the module in an exact time?


Now the proper Problem!
With YESS SIM card (brandnew prepaid card for 3G and 4G) it registers neither automatically nor manual.
AT+CSQ always says +CSQ: 0,0 (means no signal ?!)
And AT+COPS=? shows the available providers and marks the correct providers with 1 (means the providers are matching). AT+CREG? shows +CREG: 0,2 (2 proper providers available)

It always shows the messages:
+CFUN=1
+CPIN: Ready
Call Ready
SMS Ready

Question: Has anybody found out why it is doing this? Does a SIM900L doing it better?

Thank you so much
Juergen
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: navaljosh on Oct 11, 2016, 02:14 pm
Hi,

I am having the same issue. AT+COPS=? returns multiple carriers, but AT+COPS? returns 0. What should i do?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: merolicos on Jan 20, 2017, 07:29 am
I found the issue.

you have to add ";" at the end of the string
ex: ATD667755332211;

First the usb port current is enough for the sim808 (around 500ma) but less than you'll get "UNDER VOLTAGE WARNING".
The arduino voltage is enough (but high) and the current as well.

Most of the sim cards are supported by the sim808 even 4G.

If you can send sms and receive calls you need a semicolon.

Please check this log:

AT
OK

(NO NEED IT A SIM PASSWORD)
AT+CPIN?

+CPIN: READY

OK

(IF WAS SUCCESSFUL REGISTERED ON THE NETWORK)
AT+COPS?

+COPS: 0,0,"SOMETEXTHERE"

OK

(QUALITY SIGNAL, DON'T EXPECT MUCH WITH MORE THAN 11)
AT+CSQ

+CSQ: 10,0

OK

(FINALLY THE CALL :)
ATD123456789;

OK


Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: pronoob72 on Feb 13, 2017, 10:49 pm
I have bought a SIM800L eval board (ebay). I had the same issue as many describe. I could write and read commands and get it running stating
Call Ready
SMS Ready
But it never connected.

But I noticed that I could repeat doing "AT-CPIN="xxxx"" and then it would state again
Call Ready
SMS Ready

Seems like it reset immediately after this

The issue was that the Arduino board did not supply the necessary 2A to the SIM800L. I connected the sim800L (my sim800L has local regulator) to another source that could supply 2A and then it stayed on!

Now I can receive calls, send&receive sms etc.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: hashir135 on Feb 28, 2017, 12:53 pm

Hello guys

i have bought a cheap SIM800 gsm shield

https://www.aliexpress.com/item-img/SIM800-GSM-GPRS-module-STM32-SIM900A-Upgrade-board-GPS-module-C1A3/32692980971.html?spm=2114.10010108.1000017.1.dzzinm

When i press PWR_KEY the NET_STA led quickly blinks 3, 4times and then it is off.
No AT commands are working

anyone help please
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: hashir135 on Feb 28, 2017, 08:24 pm
got it. the input voltage to the sim800 was less then the rated. it was around 3.5V and when pwr_key pressed it even goes down. used 4v and everything worked fine
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: john_anderton on Mar 10, 2017, 10:05 am
Problem solved for me. This is how
My problem was similar ;

AT COPS return 1 but cannot auto register to the network

the solution was simple but it took me two days to find out

I just AT+CBAND?

the response was +CBAND: EGSM_MODE

after that I typed

AT+CBAND=?

 the response was

+CBAND: (EGSM_MODE,DCS_MODE,GSM850_MODE,PCS_MODE,EGSM_DCS_MODE,GSM850_PCS_MODE,EGSM_PCS_MODE,ALL_BAND)


For me the mode that worked is "DCS_MODE" and after I typed

AT+CBAND="DCS_MODE"


the modem connected automatically and now it is fully functional


 




Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: NickF93 on Apr 12, 2017, 05:40 pm
I've just bought SIM800L.
When I use the command AT+CPIN? it reply with "SIM not inserted" (but SIM is in). Why?  :smiley-confuse:
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: najab on Apr 27, 2017, 10:10 am
GSM SIM 800L: GPRS connection lost how it works fine? any idea please help me
it get ip 0.0.0.0

AT+SAPBR=3,1,Contype,GPRS
OK
AT+SAPBR=1,1
ERROR
END
Start
AT+SAPBR=2,1
+SAPBR: 1,3,"0.0.0.0"
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: gmora30 on May 04, 2017, 05:55 am
Hello, greetings from Venezuela.

I had the same problem, SIM800L has not connection to the operator network, Movistar in my case.

Then of change band mode with AT command: AT+CBAND="GSM850_PCS_MODE", the modem it registered inmediatly to ther network.

Then of 3 days of continuos research and work this was the magic solution, no source power, no circuitery aditional, no more nothing. Only this small change.

I hope this can be help you.

Bye!
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 17, 2017, 10:21 am
Hi everybody.
Many troubles and many good answer here. Lets make a conclussion.
I talk about the SIM800L which I want to connect to an Arduino Nano or Arduino Uno for example. The other modules are very similar

1. Connection.
Theoretical part:

Voltage/Currency:
- The Module needs 3,8V-4,3V. Some people recommend 4,2V. And 2A Currency, when it will send over GPRS. We can not use the Power of Arduino because USB give us only max. 500mA.
- The Arduino needs 5V. This is the reason why we must have 2 seperate power lines.

GND: But the Ground must be connected to each other.

RX/TX: This is very easy. RX from Sim800 goes to TX from Arduino and TX from Sim800 goes to RX from Arduino.


Ok. For now we have a connection like that:(https://abload.de/img/gprs_steckplatine0rbca.jpg)


The Problem begins now:
Some people said that we must have a diode between TX Sim800 and RX Arduino.
Others say, there must be a 10k Resistor.
Also another combine:(https://abload.de/img/16-05-_2017_13-04-16eflt4.png)


Or divide the voltage of the RX from Sim800 to 2.8V: (https://static-eu.insales.ru/files/1/4023/2502583/original/ENS-00578_4.JPG)


Onother way of this Thread: (https://abload.de/img/sim800_level_shifteryfu4r.jpg)

Many ways to came to rome or which way is correct?





Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 17, 2017, 12:43 pm
The Problem begins now:
Some people said that we must have a diode between TX Sim800 and RX Arduino.
Others say, there must be a 10k Resistor.


Or divide the voltage of the RX from Sim800 to 2.8V: (https://static-eu.insales.ru/files/1/4023/2502583/original/ENS-00578_4.JPG)


Many ways to came to rome or which way is correct?


They are all correct... Rx line (connected to arduino) will see 5V, if you power SIM800 with 4V, there is a extra 1V on that pin. So to be safe, use a voltage divider, a level shifter or whatever to lower that pin to 4V max.

If you connect RX pin directly, it can do no harm, or it can fry your module... 2 resistors cost 0,1$... why do you want to take a chance? how much cost a dead SIM800 module?


 
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 17, 2017, 03:37 pm
what do you think, will this work?
(https://abload.de/img/gprs_v2_steckplatineqozil.png)

By the way: I found a new recommendation here:
https://github.com/stephaneAG/SIM800L/blob/master/README.md
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 17, 2017, 04:16 pm
Don't use a voltage divider to feed 4V to SIM800... As soon it tries to get mA from it, voltage will drop. Use a LDO with a nice input cap. I use MCP1826 with a 470uF input cap (besides input and output recomended cap).

But you can feed 12V jack directly to arduino and use the step-down module regulated to 4V to feed SIM800 module...
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 17, 2017, 10:43 pm
Thank you. Next try:
(https://abload.de/img/gprs_v3_steckplatiner3s8d.png)

Download fritzing file (http://www27.zippyshare.com/v/STtAPIGm/file.html)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 18, 2017, 11:33 am
Sounds good... notice that:

1) MCP1826 doesn't have a 4V version, so you have to use the adjustable version with 2 resistors to set the output voltage (i use 55,7K and 10K). See datasheet

2) depending what SIM800 library you use, you may need to connect RESET pin to arduino
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 18, 2017, 11:43 am
1) should not be a Problem.
2) Can you recommend a library to achieve Post and Geht Requests over Gprs, which works with Sim800L?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 18, 2017, 05:22 pm
I've tried several libraries, this is the one i use:

https://github.com/MarcoMartines/GSM-GPRS-GPS-Shield

It is not very optimized, it has long delays, but works well.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 18, 2017, 05:54 pm
Why are you using the library which has Bugs? Did the other not Wirkung?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on May 19, 2017, 12:04 pm
I didn't say it has bugs, i said it is not optimized...
i takes about 60 seconds to establish a HTTP connection and send data, because it uses lot of delay() to wait for AT commands to execute.
The others i tried didn't work well, i don't recall all the issues i had, but this one was the only i manage to get to work.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: juan3211 on May 19, 2017, 09:55 pm
check this one:

https://github.com/Seeed-Studio/GPRS_SIM900

I have colaborated a litlle bit on it. It works well

Regards,
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: cabelyn on Jun 27, 2017, 06:20 pm
Hi there,
    Do anyone figure out how to solve this problem? I´m having the same issue not registering in operator network.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mihajlo2003 on Jul 23, 2017, 02:35 pm
Hi,
I have two SIM800L modules. First module couldn't connect to carrier. I've been trying everything I could but it didn't make any difference. Then, suddenly, the module connected! I wasn't doing anything when it connected. One week later, I fried the chip inside by reversing + and - of lithium ion battery... I've bought another module, and this one also can't connect to carrier. I've been trying everthing above, but I can't make it work! Does anyone have an idea what I can try to make it connect?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: y2kbug on Sep 04, 2017, 06:46 am
I am using SIM800C. It fails to auto-register to cell network, so I Googled and come here.

Finally I have found the reason why it fails to auto-register.

Every SIM card comes with its MCC and MNC (i.e. the ID of the mobile operator).
SIM800C has a list of of it built-in, though it could not be a complete one for the whole world.
If the operator you are using is a big one, it should be fine.
But if not, since SIM800C cannot find the operator in the supported list, it fails to register.

To fix it, find out the MCC and MNC of the SIM card, and manually register to the network.
AT+COPS=1,2,"xxxxx"
1: manual registration
2: giving the network ID
xxxxx: the network id
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: reyhandwi on Sep 12, 2017, 10:23 am
Problem solved for me. This is how
My problem was similar ;

AT COPS return 1 but cannot auto register to the network

the solution was simple but it took me two days to find out

I just AT+CBAND?

the response was +CBAND: EGSM_MODE

after that I typed

AT+CBAND=?

 the response was

+CBAND: (EGSM_MODE,DCS_MODE,GSM850_MODE,PCS_MODE,EGSM_DCS_MODE,GSM850_PCS_MODE,EGSM_PCS_MODE,ALL_BAND)


For me the mode that worked is "DCS_MODE" and after I typed

AT+CBAND="DCS_MODE"


the modem connected automatically and now it is fully functional


 





work for me, thank you  :)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mihajlo2003 on Sep 14, 2017, 08:37 pm
I've tried every mode available, SIM800L sees network but it doesn't connect. Any possible solution?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: lastchancename on Sep 14, 2017, 11:28 pm
http://www.jilaxzone.com/2017/01/26/the-world-is-shutting-down-their-2g-networks-how-does-it-impact-you/ (http://www.jilaxzone.com/2017/01/26/the-world-is-shutting-down-their-2g-networks-how-does-it-impact-you/)

Check your local carriers to see if this affects you!
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mihajlo2003 on Sep 16, 2017, 09:36 pm
Well, my carrier hasn't shut down 2G signal.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mihajlo2003 on Sep 17, 2017, 03:17 pm
Code: [Select]

AT

OK

Call Ready

SMS Ready

AT+CBAND?

+CBAND: EGSM_MODE,ALL_BAND

OK

SMS Ready

AT+CREG?

+CREG: 0,2

OK

Call Ready

SMS Ready

AT+COPS=?

ERROR

RDY

+CFUN: 1

+CPIN: READY

Call Ready

SMS Ready

AT+COPS=?

+COPS: (1,"Telekom Srbija","SCGTS","22003"),(3,"22005","22005","22005"),(3,"MOBTEL","MOBTEL","22001"),,(0-4),(0-2)

OK

AT+COPS=1,2,"22003"

Call Ready

SMS Ready

AT+CREG?

+CREG: 0,2

OK

Call Ready

SMS Ready
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mzlatar on Oct 30, 2017, 07:33 pm
Hi all,

I had same problems with SIM 800 modules. I tried with Sim800L and Sim800C.

Problem was that I was trying to power it up with Arduino 5V output. In that case module stuck in restart loop every 10 seconds.

Sometimes signal was on 0 when SIM card was inserted and full when it was out. So when I switched to 5V adapter it still was rebooting.

I had to short circuit RST and GND pins on Sim module for 1 second. Sometime i need to reset for 2-3 times and give it a minute to boot.

Module is booting fine when connected to 5V 1A adapter but immidiately shut down when recieved a call, but when powered with 5V 2A it is finnaly working!!!.

I am from Croatia, T-mobile network.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Oct 31, 2017, 11:24 am
Hi,
in the beginning flashes every half second for 10 seconds and then flashes every 3 seconds forever but sms does not send.
What's wrong?
Thanks.

(https://i.ebayimg.com/images/g/vukAAOSww5hZL4b-/s-l300.jpg)

Code: [Select]
#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   -  3.7V
GND  -  GND
TX    -  10
RX   -   11
RST  -   2

Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Oct 31, 2017, 01:00 pm
When sending sms check Vin with multimeter, i doubt you can use 3.7V to power that module... I use a stable 4.1V capable of some current (1A ou so).
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Oct 31, 2017, 07:09 pm
I use this battery (from sony ericsson)
(http://www.click3g.com/WebRoot/ce_pt/Shops/297911/5151/9461/77CE/47FE/F552/3EC1/CD0B/4520/EP-500B.jpg)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 02, 2017, 05:39 pm
As i told you, check if Vin drops a lot when sending SMS.
Minimum voltage for that module is 3.4V, so it could be power issues.
Use a 5V 1A or higher power supply with a diode or LDO to drop voltage to around 4.2V to see if that's the problem.

Or you can use other library to test for software issues.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 02, 2017, 05:44 pm
... 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?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Nov 02, 2017, 08:11 pm
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.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on Nov 03, 2017, 09:07 am
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
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 03, 2017, 11:14 am
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)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on Nov 03, 2017, 11:26 am
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?


Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Nov 03, 2017, 02:47 pm
I already ordered SIM800L V2.0. Υou will soon have news.

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

thanks
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on Nov 03, 2017, 03:28 pm
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
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 03, 2017, 07:28 pm
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
 
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 03, 2017, 07:40 pm
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
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Nov 04, 2017, 12:06 pm
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?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on Nov 04, 2017, 12:12 pm
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
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 06, 2017, 10:51 am
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. 
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: luhcforgh on Nov 28, 2017, 11:20 pm
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.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: dannable on Nov 29, 2017, 08:49 am
I worte a short piece on how I got mine to connect:

https://forum.arduino.cc/index.php?topic=496064.0 (https://forum.arduino.cc/index.php?topic=496064.0)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Nov 29, 2017, 01:21 pm
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).

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.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: nksl on Dec 16, 2017, 08:25 pm
SIM800L V2.0 5V
(https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSXUGyPMx_FbWlM4BDDmscLM4LDcgK6EYonW7fcKphkbheH5yG9)

Code: [Select]
/* 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 :(
   
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Dec 18, 2017, 03:28 pm
Do you see module led blinking?
How do you power that module?
Print "error" variable to see what is happening.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mortenx on May 27, 2018, 09:55 pm
Can sim800L chip work in EDGE network?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 27, 2018, 09:58 pm
Can sim800L chip work in EDGE network?
It works only in EDGE network
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mortenx on May 27, 2018, 10:54 pm
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 ?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Kingside on May 27, 2018, 11:07 pm
Dont try ot on my own, but the documentation says, you can switch the EDGE Mode On or Off.
https://codius.ru/file/download/4f7cb937-b8a7-4e28-bd24-c23d9a03c9da
on page 200
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mortenx on May 27, 2018, 11:27 pm
this CEGPRS command gives error.. is there some command that comes first ?


AT+CEGPRS=?
ERROR
AT+CEGPRS?
ERROR
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: mortenx on May 28, 2018, 10:53 pm
Same problem, module is seeing network but dont connect...



Finding Networks. Please wait..

AT+COPS=?

+COPS: ,(0-4),(0-2)

OK
Available Networks:
Finding Networks. Please wait..

AT+COPS=?

+COPS: (1,"TELE2","TELE2","24803"),,(0-4),(0-2)

OK
Available Networks:
Network Name->TELE2
Network ID->24803
Network Status->Available

AT+COPS=4,2,"24803"

ERROR

+CPIN: READY

Call Ready

SMS Ready
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: bhuvanbam on Jun 23, 2018, 03:20 pm
You can visit the site for more information, click here (https://techfries.co/mobile-network-not-available-error-android/)
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Josip21 on Feb 19, 2019, 08:34 pm
I have purchased SIM900 and still waiting for SIM800C and SIM800L. Firstly I attached my SIM900 directly to the UNO and it didn't connect to the network. Afterwards I tried it over a breadboard supply and the result was the same. Still I have several 2G networks available. So after a triple flash on the SIM900 module a NetLight (D6 led diode) goes off. Now I'm waiting for an AC/DC power supply with 5V and 2A, some ESR capacitors, diodes,... for more tries. In my opinion some of these problems comes from 2G network unavailability while some are power supply related. According to the datasheet from the manufacturer all these SIMs need 4 Volts and in peak 2 AMPS, either through a boost or a DC-DC converter. I plan to make a small circuit and to position it the closest possible to the VBAT (34, 35 pins) and GND (36, 37) as shown in two attached JPEGs. If you are making your own PCB board the manufacturer also recommends lines at least 1 millimeter thick. Hopefully this could solve some of our issues.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Jayesh_Adwani on Apr 14, 2019, 06:20 pm
2g sim card is not available here in India so i like to have some advice what to do if gsm module800A not registering on network
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: puthre on Apr 18, 2019, 07:51 pm
Check if the IMEI number written on the module matches the number that you receive on the AT+cgsn command.

I have the same problem described here (cannot register to network) and these numbers do not match and I suspect that the issue is that I might have a cloned module.

Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Jayesh_Adwani on Apr 19, 2019, 07:11 pm
AT command is not working..!!
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 22, 2019, 10:49 am
2g sim card is not available here in India so i like to have some advice what to do if gsm module800A not registering on network
SIM800 is a 2G modem, if 2G is not available in your country, you cannot use it.
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Jayesh_Adwani on Apr 22, 2019, 01:22 pm
Any idea which module to use..?
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: geologic on Apr 23, 2019, 10:54 am
Well, check UMTS modules like sim5320 or the new narrowband (if available in your country) like sim7000
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Jayesh_Adwani on Apr 23, 2019, 02:26 pm
Thanks anyway..!!
Title: Re: Cheap GSM module (SIM800) not connecting to the network
Post by: Laythsaadi on Jul 15, 2019, 01:24 pm
 Try to see this video

https://www.youtube.com/watch?v=65kPBdyzGF4