29 votes
Accepted

What is the difference between MQTT and Web Sockets, and when should I use them?

The question setting here is little bit misleading, because actually these protocols cannot at all be compared together. They are like TCP and IP, layers above each other. [1] Websockets is a low ...
user avatar
  • 4,301
14 votes
Accepted

How does an Azure IoT Hub interact with Embedded/IoT devices?

The model that IoT Hub connected devices use is that they will never accept incoming connections. IoT Hub devices never act as a 'server', and this is a crucial part of the security model in Azure IoT....
user avatar
  • 1,483
13 votes
Accepted

Is CoAP still used for IoT devices?

The reason that you find few implementations is most likely because CoAP is a relatively young protocol. It was first proposed in 2010, and the current version dates from 2014: RFC 7252. For ...
user avatar
  • 351
11 votes

What is the difference between MQTT and Web Sockets, and when should I use them?

They're comparable in that both allow you to have full-duplex communication such that the server can immediately pass data to the client, without the client polling for it (as might be with HTTP). ...
user avatar
10 votes

How can I monitor IoT devices in real-time while on a plane?

Some airlines provide in-flight wireless connectivity, usually for a fee. You can use WiFi in "Airplane Mode" on most mobile devices, so that would let you connect to a monitoring server to retrieve ...
user avatar
  • 782
10 votes

How can I easily configure Wi-Fi on a smart device without a screen?

A usual method is that the IoT device sets up a temporary Wi-Fi access point. This AP can be open, or the password et cetera can even be coded into a QR Code. Such codes can easily be generated by ...
user avatar
  • 8,095
10 votes
Accepted

How can a device get the SSID and Password of my Network without WPS?

If you are using an ESP8266 the built in Smart Config feature can achieve this. An example can be found here: ESP8266 Arduino WiFiSmartConfig.ino. The important steps are to set to STA mode: WiFi....
user avatar
  • 216
8 votes

Is Bluetooth 3.0 suitable for a single-master multiple-slave network?

From the perspective of power usage, Bluetooth 3.0 does not seem like a viable choice, given your constraints. Let us assume that you want to transmit data for 2 seconds every minute, and then sleep ...
user avatar
8 votes
Accepted

How can I easily configure Wi-Fi on a smart device without a screen?

Some devices support connecting to a router through Wi-Fi Protected Setup (WPS), which is a feature of most modern routers to allow any device to connect to your network (with a limited period of time ...
user avatar
8 votes
Accepted

Does XMPP have a large overhead for IoT devices sending short, frequent messages?

While it's fair to say that XML is verbose, that should be tempered with the awareness that this verbosity is not all "overhead" in relation to content since it encapsulates semantics; it's ...
user avatar
8 votes
Accepted

Is there a way to preserve the MQTT QoS level until it reaches the client?

One thing to remember when working with MQTT is that "both subscribers and publishers are considered MQTT clients". As said QoS set while publishing is entirely related to broker(B) not the other ...
user avatar
  • 1,480
8 votes
Accepted

How do car insurance tracking devices connect to the internet?

Most of the telematic devices used by insurance companies use cellular phone devices (mostly using 2G which is fairly commonly used for low cost, low data requirement devices) to communicate with a ...
user avatar
7 votes
Accepted

How reliable is location tracking of shipments?

I am not certain that this is an IoT question. I have the impression that those tracking devices would not get any GPS signal in shipping containers, trucks or buildings, where they would be most of ...
user avatar
7 votes
Accepted

Does CoAP have a lower footprint than MQTT?

CoAP and MQTT have both equal RAM usage, measured in 10kbits [1]. Difference is in cpu and network usage: [2] Every client supports TCP and holds a connection open to the broker. So, CoAP has ...
user avatar
  • 4,301
7 votes
Accepted

Raspberry Pi to send sensor's data to server continuously and receive commands from server

Ok here goes Install MQTT on your Raspberry Pi Look if it is already running on your Rpi linux flavor or install it Expose your MQTT port Look at which port MQTT is installed and open this port ...
user avatar
  • 3,656
7 votes

Trying to switch my lights off in my smart home

You should start with Wireshark for network monitoring. Watch out for headers (authentication, certificates,...) I think you should use a Raspberry Pi to interface your module, it could be a quite ...
user avatar
  • 3,656
7 votes

SSH into an Orange Pi connected to the internet via 2G GSM module

Most cellular providers use Private IP (RFC-1918) ranges (e.g. 10.0.0.0/8) and NAT for their networks which means it is not possible to directly access a device connected via these networks remotely ...
user avatar
  • 12k
7 votes
Accepted

Is there any way to access local server from outside without port forwarding?

You have to provide an endpoint of some sort to allow control over a given device. Port forwarding is not the only option, the device could connect out to a publicly accessable server on the internet, ...
user avatar
  • 12k
7 votes
Accepted

Are there standardized MQTT topics?

In general, no — there aren't any standards for topic naming beyond the MQTT specifications. There are plenty of opinions about how you should construct your MQTT topics, and not a lot of fixed rules. ...
user avatar
6 votes
Accepted

What Messaging Type can be used for Cellular Network Oriented IoT Protocols?

Are you asking about the protocol or the message format? We often incorrectly use the term protocol when we mean the format of the data. I do this myself, often because the distinction isn't clear to ...
user avatar
  • 1,483
6 votes

Is Bluetooth 3.0 suitable for a single-master multiple-slave network?

I have document some aspect of BLE low power aspects as a response to What is the difference between Bluetooth Low Energy and Bluetooth BR/EDR in Park mode?. Here are is a suggestion. Looks like a ...
user avatar
6 votes

How can I synchronise data between devices, avoiding loss of messages and duplication?

Typically, you would need to choose a protocol with strong guarantees on whether the client will receive any packets/messages, in which order, and whether duplication is permitted. For a network of ...
user avatar
6 votes

How does APN affect cellular connectivity?

This confusing behaviour is typical. The underlying reason is that it is up to the carrier to decide what to do with the APN setting — unlike most configurations of this form, you're not actually ...
user avatar
6 votes

Medical data IoT communication protocol?

I do not think the whole topic of complying with the GDPR legislation in Europe can be addressed in a single SE question. Therefore, I will simply stick to the question, which communication protocol ...
user avatar
  • 570
5 votes
Accepted

Is Bluetooth 3.0 suitable for a single-master multiple-slave network?

Alternatively it might be worth to consider wireless Hart (Highway Addressable Remote Transducer). This is a 2.4GHz ( license free frequency band) Smart mesh networking technology that uses 802.15.4 ...
user avatar
5 votes
Accepted

Trying to switch my lights off in my smart home

I've not looked at the system in detail, but it looks like it really should have properly encrypted/authenticated transmission. This means that unless you can extract the app's private certificate, or ...
user avatar
5 votes

How do I check whether a LTE network supports CAT M1?

I tried hard to find out an AT command for that, but unfortunately I didn't find it. Instead I found semi new slides about m1 and m2. https://www.slideshare.net/mobile/SmallCellForum1/discussion-...
user avatar
  • 4,301
5 votes

What is the library to be used to implement CoAP in ESP8266?

There are no standards only RFCs for CoAP; all of them are accessible on the web: RFC 7228 - Terminology for Constrained-Node Networks, May 2014 RFC 7252 - The Constrained Application Protocol (CoAP),...
user avatar
5 votes
Accepted

How Smart Home devices communication works

The answer is that the device connects out to the control server and maintains this connection. The control server then uses this connection to forward requests. Typically messaging protocols like ...
user avatar
  • 12k
4 votes
Accepted

How to start IoT development to send commands from IoT Hub to Device

Arduino is an open source platform for IoT test projects, and you'd buy either a Arduino device or a cheap derivation, that may have cheaper price or better characteristics. Same Arduino IDE can be ...
user avatar
  • 4,301

Only top scored, non community-wiki answers of a minimum length are eligible