How to control gpio pins of Arduino with internet

[Christian-Me]

Hi,

a lot of beautiful insights an thoughts. A few things kept some question marks in my brain .

@unixneo

I find the more reliable way to do this using GSM, 3G, 4G, etc is to use a mobile phone as a hotspot and connect your device via WIFI (this often means using an ESP device like the ESP32 or the ESP8266).

Why you like to add another hop (node - Wifi - phone - GSM - network) in the communication. The Sim800l is a serial to GSM converter (like the first ESPs where designed as serial to WiFi converters. There origin are GPS car / dog and what not trackes. I agree that in the western world GSM has a good coverage (and in Germany recently they decided before switching off GSM all others (UMTS, 2G ...) will be ditched first to have always a basic phone and small data network)

@unixneo

The different is that with the ESP32 there is a better reset function available and so when your connection is lost, sometimes these ESP devices will not reconnect robustly (the same is also true for LoRa and NB-IoT btw).

In a stable design you hopefully don`t need a watchdog (often). And the watchdog sits in your micro (or perhaps even better outside in a dedicated chip. So the quality of the watchdog design has nothing to do with if you are using WiFi or LoRa for your WAN design.

Don't get me wrong I love my ESPs. But to keep an eye on them I desigend my remote-device-table. Especially the nodes in the garden are getting into trouble too often. If there are only sensor nodes it is not a big deal but for actuators or "important sensors" it is. Before you ask I`m using Ubiquiti UniFi APs at home. Depending on the weather (rain = bad) the connection quality results in low uptime rates (as my firmware resets after a certain amount of failed connections). But none of my nodes is able to run longer than around 10 days without a reset.

When it comes to RF communication a often ignored point is antenna design. The ESP (Especially the AIThinker designed modules) comes with a very good designed PCB antenna (I found them better than many china dedicated antennas). If you place the module good in your design of your device you get fantastic reach.

When it comes to encryption I mentioned the (OTA) link between your device (ESP / Arduion / STM32 ...) and your AP ... I only wanted to say that if it is difficult (not impossible) for the ESP32 to do proper encryption I think it is nearly impossible for a small Atmel (Arduino). Perhaps again LoRo is an option because it brings their own encryption

Chris