SIM800L GPRS GSM ( ROHS ) restarts every 10 seconds

Hi i am experiencing the above problem with this module

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i am using Arduino mega 2560 with this one and i am including the SoftwareSerial.h to declare pins 10 and 11 as RX and TX in my code

my PIN connections to this module are

SIM800 5v/4v ↔ Arduino 5v (or external power through MB102 Breadboard Power Supply Module 3.3V/5V For Arduino Breadboard.. This one below )

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SIM800 GND (first one) ↔ Arduino GND SIM800 SIM_TXD ↔ Arduino D10 TX SIM800 SIM_RXD ↔ Arduino D11 RX SIM800 GND (second one) ↔ Arduino GND For common reference for tx,rx

With the Sim card in place and through the Serial monitor i can send AT comands and receive back messages

Sending AT and get :

OK +CPIN: READY Call Ready SMS Ready

Sending AT+CFUN? and get :

+CFUN: 1

Sending AT+CREG? and get :

+CREG: 0,2

Sending AT+COPS? and get :

+COPS: 0

Sending AT+CMGF=1 and get :

OK

Sending AT+CSMP? and get :

+CSMP: 17,167,0,0

But all of these commands i can send them only between the 10 seconds that takes before restarts again

The module has 2 leds... the one red is always ON in these 10 seconds and the second one also red in colour is blinking

When i dont have the SIM card inside the slot the module doesn't Restart , is always on with the 2 leds working as i describe above

Any one with the same problem and perhaps a solution to this? what i am doing wrong ?

OK i find out something strange....

This happens only when i have connected the Antenna to the module

When the antenna is out the module works fine without restarting (i havent test it to send AT comands but i am guessing it will not be able to find the gsm network

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SO any idea about this ?

Thanks in Advance

Youre not giving it enough power. Those board supplies are typically 5-700ma

Id imagine without the ant, the device fails to see a network. When you add the ant it sees the network and attempts registration...which ups the power requirement as the tx stage fires up.

How we can guarantee the 2A

I have the same problem with the SIM808. Did you get it to work?

Try to connect with a charged LIPO 3.7 or charger that provides 2A and voltage under 4.4

You have to connect the GND of arduino with GND of LIPO (common GROUND)

IF does not work, buy sim800L (red pcb), I never had problem as the above module

hi!

i am using the same module, and have the same problem like mr caslor. from my experience in this sim800l v2.2 module, it is not problem with power supply, because i am using laboratory power supply that can provide more than 2A. I did test 3 sim cards, and all 3 of them behave differently. i tested 2 sim cards of same network operator but 1 was newer and micro type, and another was nano with adapter. when i was using micro sim card from that operator, one led that continuously lighted and another was lighted 8 times and then module was reset. sim card from another operator: one led was lighted continuously and another was lighted 10 times and then reset. the older sim card from 1st operator - micro sim card was around 4 years old. with that card i have no reset but also no connection to mobile network.

at+cops?

+COPS: 0

OK

it is not problem with power supply, because i am using laboratory power supply that can provide more than 2A

It is not guarantee you are supplying GSM module the right way. sim800l needs power supply voltage 3.4-4.4V recommended 4V. Burst may produce problems because i can pull up to 2A current and if you have long wires it may produce voltage drop across it and GSM module will reset. It is good practice to solder electrolytic capacitor as close to the module as possible. I use 1000uF 6.3V cap and it helps. It is better to use a couple of lower capacity low ESR type capacitors.

On this link you'll find the pdf document http://wiki.seeedstudio.com/images/4/46/SIM800L_Hardware_Design_V1.00.pdf Look at page 21 and couple next pages for sim800l power supply recommendations.

Best regards...

mr bole, thank you for your answer very much! i find a problem. and i believe that your solution with capacitor of 1000mf close to connector on module would solve the problem as well. the problem was wire that i was using to connect sim800l. i was using this type of wires http://www.5thpostulate.com/image-smp/5pe-male-female-jumper-wires-dupont-arduino-cables-8-cm-pack-of-10-dupont-arduino-jumpers_78503_1000x1000.jpg i believe that this type of wires is very tiny to provide enough current in the moment that module is starting to send/receive gsm signal. only thing i did, i put this type of connector https://www.allelectronics.com/mas_assets/cache/image/4/4/3/480x480-1091.Jpg and connect female one directly to sim800l module.

i am using: https://www.tokopedia.com/viekashop/sim800l-v20-sim-800l-gprs-gsm-module-sim-board my Work voltage: 3.7~5V

few minutes ago, i make a first call to the module from my cell phone... can you imagine how i was happy when i saw a massage RING on terminal :D :)

Hey guys, I had the same problem on sim800c and increasing voltage to 4.1 volts fixed the problem on 4.00 volts it power's down after about 10 seconds blinking of net led

use 1000uF 6.3V cap and it helps. It is better to use . in gsm wants to 5v,1.5-2A .we place a cap b/w vcc,and gnd

power the sim module directly from external 5V min. 2Amp power supply ( do power from the board) and must work.

sim800l has some naked SMDs on it, you don't want to put your bare hands on them, i impaired one long ago when i was a noobie ,

hold the board on it's edges,

I had the same problem but I solved it by replacing the tantalum capacitor on the SIM800L EVB. On my board was 107, which is 100uF, I changed it to 108, which is 1000uF. I made the exchange on all five modules I’ve bought on aliexpress and have been working since then.

cz-themax: I had the same problem but I solved it by replacing the tantalum capacitor on the SIM800L EVB. On my board was 107, which is 100uF, I changed it to 108, which is 1000uF. I made the exchange on all five modules I've bought on aliexpress and have been working since then.

This is interesting solution. Where did you found 108 tantalum capacitor? I found that they cost about same as whole board from aliexpress :)

Adding 1000uF 6.3v Aluminium Electrolytic capacitor causes sparks when I connect the DC power supply. How can I solve this issue? I guess the sparks destroyed the SIM800L.

I’m having exactly the same issue as described above with sim800L red module.
Attached is the schematics.
I have tried few modules and always the same result.
10-12 blinks and module resets itself

AT communication works fine.

LM is set to provide 4.2V and after diode i have 3.7V

I am using 5A power supply.
i have tried adding 2x470uF caps before modules but still no change.

EDIT:

After fiddling around i found that sim800’s are very sensitive to the cable quality on power line.
So i replaced vcc and gnd connection cables on breadboard with good quality cable from power supply, suddenly all my problems are gone and sim800 works just fine and as expected.

neki_deki: mr bole, thank you for your answer very much! i find a problem. and i believe that your solution with capacitor of 1000mf close to connector on module would solve the problem as well. the problem was wire that i was using to connect sim800l. i was using this type of wires http://www.5thpostulate.com/image-smp/5pe-male-female-jumper-wires-dupont-arduino-cables-8-cm-pack-of-10-dupont-arduino-jumpers_78503_1000x1000.jpg i believe that this type of wires is very tiny to provide enough current in the moment that module is starting to send/receive gsm signal.

Mr. neki_deki, I crossed the same dark valley of the thin wires. Now my SIM800L don´t flash anymore. I can send and receive sms. Thanks

cz-themax: I had the same problem but I solved it by replacing the tantalum capacitor on the SIM800L EVB. On my board was 107, which is 100uF, I changed it to 108, which is 1000uF. I made the exchange on all five modules I've bought on aliexpress and have been working since then.

Hello,

I would like to know where you find the capacitor 107.

Thanks