Sending and Receiving SMS with a SIM800 GSM Module - Tutorial (#124)

The SIM800 is a low cost SMS module that you can use in electronic/IoT projects. It does have a few quirks, though. I set one up here and show how to send and receive text messages.

See also:

[amoldipina]

good video, use 4v to main VCC with a 1000uf cap, because wen he burst signal needs 2A, at the RX put a resistor devider on RX of 10k on signal and 20k to ground, the rx are not 5v tollerant.

[fik_of_borg]

Great video, pointed me in the right direction. Things I had to do to make mine work:
1- Raise a bit the voltage, from 3.3 to 4V (added a diode between the 1117 regulator and gnd)
2- Put a 470uF cap between Vcc and GND
3- Connected DTR pin to gnd (this make the module answer consistently)

[doverivermedia]

Very interesting and insightful. Thoroughly deserving of my rare subscription. Great channel to help me in my efforts to learn microelectronics. Thank you ! ... 🇬🇧

[iantcroft]

Great informative video thanks.
I too have used this module and had similar issue. Like you say, I think it’s down to the thickness of the wires. It would be good to see a video illustrating this. Also a popular video would be if you include a gps module with the Sim800L you have a tracker.

[samirdjelal]

Thank you, after spending 10 hours trying to make it work without external battery, adding 1000uF capacity solved the issue, and now I can run it with the 5v pin from ESP32 directly

[Romello_Pietersz]

I gave mine 5V with a 2200uf capacitor, and thicker power cables. Since then it had not failed.

[Gonzalo-fw]

muchas gracias, colocamos un capacitor a la entrada y todos los problemas se solucionaron

[ricardosapayan]

is there a way to make work the sim800c gsm module? were can i find library.tnx

[NamasenITN]

Your video is very precious. Where did you find the complete documentation of that module, if I might ask you for it?

[Sergio-takrt]

I spent 4 days to recieve any response to my AT commands. I tried all baud rates and can't get any response from module :( even I bought USB-ttl and doesn't recognize my module too, don't know what to do else..

[mohammadatiah]

Hello brother, I want to ask you about the sim800l electronic part. I am doing in a project and there is no broadcast. What should I put a SIM and it is in my city 2G or 3G? Thank you, brother. I hope you help as soon as possible

[ianhayden]

When I input the command AP+ csq it outputs 20, 99. I can’t figure out why it is picking up little to no signal and therefore will not send an sms

[supriyasunil]

Hi! Nice video very helpful! Could you please specify how you soldered the capacitor? I have a sim800l v2.0

[luigidefalco]

Does this module support SMSCaster for windows? Or any other GUI app

[paulelliott]

Hi ... Great video !
Can the bell output be fed directly into arduino digital port to detect hi/low .. I want to trigger a relay and operate a factory analog bell ..
Thank you
Paul

[jimrock]

Hi...is this module reliable for industrial applications? Have u ever tested these GSM modules by running them for some days, weeks or months?

[thestateofreal]

Do you need an activated SIM card from a cellphone carrier in order for this to work?

[fernandohood]

The wifi module uses carriage return and newline. Does this only use carriage return?

[dr_ned_flanders]

A 1000uF capacitor doesn't work but it does work when it is a much larger 2500uF 25v cap I can get mine to connect to the network.

[pabinstruments]

i check with postpaid sim card and send massage to 5 mobile numbers but some mobile numbers received blank msgs.and some are able to read. if i insert prepaid sim card it works well
what will be the problem?
Thanks in advance