In the second part of our short http course we will look at http headers. If you’ve missed part 1 then here it is- Part 1- http basics
Continue readingUsing cURL for Testing IOT Applications
The http protocol is the main protocol used on the web, and because of its widespread adoption it is also used in IOT applications. Many IOT applications like the Thingsboard Dashboard support both http and MQTT. In this tutorial we will start with a general introduction to cURL and show examples of using cURL to get and POST data.
Continue readingUnderstanding And Using MQTT v5 Request Response
Web Applications have a direct connection between the sender and receiver. The sender is the client (web browser) and the receiver is the server. They implement a command response message flow were the client(browser) makes a request and the server responds and there is a direct connection between client and server.
Continue readingMQTT v 5.0 New Features Overview
MQTT v5 introduced many new features and changed how some existing features work. In this tutorial I will be covering all of these features with brief examples, and also in many case, links to detailed examples and videos.
Continue readingHandling Multiple MQTT Client Connections Using Python
It is common to require several connections either to a single broker or to multiple brokers. There a several ways of achieving this and we will examine two ways. First let us recap on what we require with a single connection.
Continue readingIPv6 Explained for Beginners
IPV6 has been developed to replace IPV4 which is running out of addresses. Although it has been around almost 10 years it is still not widely deployed and supported. However adoption rates are increasing rapidly and IPv6 traffic crossed the 10% threshold in February 2016 (wiki) .
Continue readingUnderstanding IPv4 Addressing and Address Classes
IPv4 has been in use since the start of the Internet, and is widely deployed across the Internet, and home networks. In this tutorial we will cover the basics of IPv4 Addresses. You will Learn IPv4 address structure IPV4 Address classes Special and reserved IP addresses Broadcast Vasics
Continue readingUnderstanding and Using Buffers In Node-Red
When data is read from a file or network it is read byte by byte into a data buffer. Data Buffers are temporary storage used for transferring data. To work with binary data we will need access to these buffers.
Continue readingReading and Writing Data Using Buffers -Nodejs & Node-Red
What is a Buffer? -A buffer is an array of binary data. Each element in the array is 8 bit binary data. When are buffers used? -Buffers are used when you need low level access to data usually that has been received on the network or from the file system. Data stored on computers and transferred between computers on networks is stored or sent as a sequence of bytes. When you read data from a file or from the network it is read into a data buffer. Node.js Buffer Module To work with buffers in node-red we use the node
Continue readingCreating and Using Client Certificates with MQTT and Mosquitto
Another popular way of authenticating clients is via client certificates and can be use as in addition or as an alternative to using user name and password authentication.
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