MQTT over SIM800L IoT

[the German]

There are boards with the ESP32 and the SIM800 modem for about 15 €,

but I think the ESP8266 and a SIM module for about 3 € are better, the ESP32 needs a lot of energy.

There are good SIM cards to buy in Germany, at Telekom 500MB cost 12€, at Vodafone 1.5GB 15€, the cards and the credit are valid for 10 years!!!  (0,13€/ month)

The cards are valid worldwide roming. Since M2M IoT cards are almost always valid worldwide, there are definitely other sources of supply all over the world.

My GPS data logger sends every 3 minutes, it needs a maximum of 3MB / month,

There are cards for a special energy-saving protocol, but that needs special modem modules, so I prefer the old 2G variant, because SIM800 (L) SIM900 also work, dial-in and data is sent like a serial modem,

Now it is obvious to send MQTT, your solution works perfectly via wifi, but now it would have to be packed into the serial data string,

do you have any ideas, does it sound interesting to you?

[cicciocb]

Hi, 

what do you propose, in fact, to add the support for the SIM800 modem ?

[the German]

I have now only ordered SIM800L, when these are there I want to control them,

I want to monitor heating and electricity meters that are far away, it is very helpful with the price of the SIM. as soon as these are there I will report

Now I've thought about whether it is even necessary, a small LTE router, GSM router should also have no traffic if only ESP modules are actually involved. you could even step onto the annex surface.

[erhard.f...@gmail.com]

This module sounds interesting to me too. I would love to have it supported by annex, because there are lots of valuable projects to accomplish.

[the German]

the module has arrived, It works well,

you have to note that current spikes need much more than 2A, 10cm cable to the lithium does not work, 4cm works.

you can call, send sms, send tcp and udp packets, it can also read http headers (telegram bot maybe).

with the vodafone iot card i get an IP4 IP, this will not be the case with other cards.

There are more expensive SIM 7000 that can MQTT directly, but the Sim800 for 3 € is affordable.

[Fabrizio Bellini]

Hello I'm also interested in this SIM800L I ordered a version 2 (5Volt).

https://www.amazon.it/gp/product/B07RKVL1DW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

  I wanted to know if you can share a few lines of code regarding his programming so that I can start my tests Thanks  

[the German]

I haven't had time to write annex code yet,

it is easy to execute commands in a terminal program "Termite" using copy past,

the module needs 5W peaks, even at 5V they have to come from somewhere, that is the transmission power of all GSM standards, it can also come from really large capacitors, the module responds at every baud rate, with 19200 it worked best, I had problems at the beginning because the card wanted to log into the network but there was not enough electricity, the communication was disturbed and the answer came in a different baud rate, or reset,

the best description is: https://lastminuteengineers.com/sim800l-gsm-module-arduino-tutorial/

[the German]

It is possible to buy a GPS tracker, about 15 €,

because you have everything together, battery, GPS module and a SIM module (all are a bit similar to the sim 800) you only have to unsolder the controller and serial data lines to the ESP,

[Fabrizio Bellini]

Thank you very much for the reply, I saw the SIM808 version which includes GPS 

https://www.amazon.it/SIM808-Module-Breakout-Arduino-Raspberry/dp/B07GBDMMH4/ref=sr_1_2?__mk_it_IT=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=sim808&qid=1611142432&sr=8-2

but at the moment I don't care, in fact it makes a tracker possible with little expense 

  Fabrizio