SIM808 Module restarts continously using Vodafone SIM

Hi All,
I recently bought the following Arduino compatible sim808 breakout board in order to handle GSM,GPRS and BT on a learning project:

I have one issue:
looking at the led blinking and the serial monitor it seems that the board have unexplicable periodical restarts. When I send "AT" command I see the successfull answer "OK" and some string as:
Call Ready
Sms Ready

But I receive this message too often!
I tried to set AT+CMGF=1 (sms string mode) but after some seconds it comes back to the default value AT+CMGF=0.. (that's another reason why I think board is restarting)

Someone of you can help me? Someone had similar issues?

I'm using italian vodafone sim.


Power supply?

Power supply?

5v-10v.. (5 recommended)
I'm testing it with arduino so 5v..

Unfortunately that really doesn't say enough.
POWER is a function of VOLTAGE and CURRENT.

Your supply may be ok, but chances are, the modem pulls more current while registering, which in turn, causes a reset of the 'duino.

Those messages 'Call ready' and 'Sms ready' are a bit suspicious.
You may need to post your code and a snippet of your dialog (from serial monitor) with the modem.

At this stage, save your sketch, and cut it down it to the bare minimum code needed to interact with the modem, or use one of the pre-packaged 'test' sketches to talk & listen to the serial port.

BTW, you SIM80x will become a 2G paperweight in the coming months.

BTW, you SIM80x will become a 2G paperweight in the coming months.

can you elaborate ?
is it becuase the world is comming to an end becuase of the American election ?
asteroid perhaps ?
it is not the A6 POC..... that is a bit premature.

also, since a SIMM card is needed and here in the US, it seems that only T-Mobil has a SIMM that does not require a device serial number, is the new kid on the block going to offer anything better ?

My need is for a nest.

Check out (about half way down) for the general idea...
2G shutdown
From what I see elsewhere, the dates are a bit loose, but I expect maybe 1/2 of the first world countries will be closing down 2G by the end of 2017 - to release spectrum for 5G

"T-Mobile US has postponed shutdown of their 2G network until 2020."

since T-moble in the US is the only carrier that supports devices without serial numbers (that I have found so far) , just need SD cards, then all is good for a short time.

but that begs the question of what technology to use ?

I suspect Australia may unwind their plans (started shutdown yesterday)
I'm Already hearing that some sites have to swap modems - based on which carrier they're using (all using different combinations of 3G bands!)

Yes, i'm affected too. with multiple sites (sigh)

5v-10v… (5 recommended)
I’m testing it with arduino so 5v…

What is you 5v power source and what current can it provide ?

The Sim module can take up to 2 Amps for short periods, so you need a decent 2A supply, though I have managed ok with a 1A supply and a 2200uf capacitor.

I found the solution..
Sorry but I'm more sw-friendly (I'm starting now trying electronic stuffs) and I couldn't give you more elements. The problem was that I supposed to make arduino and gsm board work only using usb power supply :smiley:

I tried connecting a 12V 3.3A power supply to the Arduino Board and now everything seems to works correctly.

Now I would like to find a battery able to feed them in the same way.. can you suggest me which kind of battery should I choose? I would like to keep the prototype turned on for some days.. of course not keeping GSM continuously activated, but only periodically.. it is possible?

thanks to everyone

It is still a mystery, it is not because it is not work, but because sometime I test with some AT command and it is work.

(No doubt, it will work when I powering it with car battery, using some step down circuit).

I still wonder if SIM808 can be power just by regular powerbank, so I make some AT command test. This is the cronology that make the SIM808 on and detect the sim card.


response: OK

response: +CME ERROR: SIM not inserted

response: OK

response: +CPIN: READY OK


After that, the device turn on and detect the sim card, I already test by http get to access an API address.

The problem is I'm not sure I can recontruction the testing AT command to arduino script. Somehow it need the exact timing to power up the device (by AT+CFUN=1,1).