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In this tutorial, we will expand on the Arduino Web Server tutorial to include reading the values measured by a sensor. This will allow us to view the data by simply opening a page in our browser. For this example, we will measure the temperature using a DHT11 sensor and measure the distance from an object using a proximity sensor. To control the built-in LED on the Arduino, we can send requests to the /on URL to turn it on and the /off URL to turn it off....

Introduction Reading files is a common operation when working with Node.js. In this blog post, we will explore different options for reading files using the fs module in Node.js. We will discuss the traditional ways of reading files, as well as a more efficient method using streams. Traditional File Reading Methods Method 1: fs.readFile() The fs.readFile() method provides a simple way to read files in Node.js. It takes the file path as its first parameter and a callback function as its second parameter....

Recurring revenue has always been a double-edged sword for me. On one hand, the idea of having a product with a steady stream of customers who pay a monthly or yearly fee sounds great. But on the other hand, every time I’ve tried to implement it, I find myself hating it. I’m no stranger to the concept of recurring revenue. About a decade ago, I had a successful open-source software business that relied on recurring license fees for support and updates....

Redis, a widely-used in-memory data structure store, offers a versatile range of data structures that can greatly enhance the efficiency and performance of your applications. In this blog post, we will explore one of Redis’s fundamental data structures called Lists. Introduction to Redis Lists A Redis List is an ordered collection of strings, where each string value is associated with an index. What makes Redis Lists powerful is their ability to efficiently perform a wide range of operations such as adding, removing, and retrieving elements from both ends of the list....

Redis provides an efficient and straightforward publish/subscribe messaging mechanism. This feature enables publishers to send messages on specific channels, which are then received by multiple subscribers. To subscribe to a channel, use the following command: SUBSCRIBE <channel> For example, to subscribe to the “dogs” channel: SUBSCRIBE dogs To publish a message on a channel, use the command below: PUBLISH <channel> <message> For instance, to publish the message “Roger” on the “dogs” channel:...

Regular expressions can be a powerful tool for finding specific patterns within strings in Python. With the re module, which is part of the Python standard library, you gain access to a set of functions that allow you to work with regular expressions effectively. Searching and Replacing Two commonly used functions for working with regular expressions are re.match() and re.search(). These functions take three parameters: the pattern, the string to search in, and flags....

When working with the relational model, there are two groups of operations that can be used. One of these is known as relational algebra, which serves as the basis for SQL, the widely-used language for working with relational databases. The other group is relational calculus, which takes a declarative approach to interacting with databases. In this blog, we will focus on relational algebra and its primary and join operations. Primary Operations in Relational Algebra Primary operations are the foundational operations in relational algebra....

Relational Databases serve as the software embodiment of the principles outlined in the Relational Model. These databases organize and store data in tables, each with its own set of columns designed to store specific data types, such as strings or numbers. The combination of a table and its column specifications is known as a schema. Additionally, tables can apply constraints to ensure the integrity of the data they contain. One of the defining features of relational databases is the ability to establish relationships between tables using foreign keys....

Launching a product or course requires effective marketing to ensure its success. As a senior developer, I understand the importance of reaching out to potential customers and capturing their attention. While some may argue that sending multiple emails can be excessive, I’ve observed that in non-technical markets, more emails are often received. However, even in the tech industry, I have witnessed launches with a significantly higher number of emails. During my own launch, I made sure to provide an option for recipients to opt-out of the launch emails while remaining on my general mailing list....

If you’re looking to remove the first character from a string in JavaScript, there is a simple and efficient solution available. By using the slice() method, you can easily achieve this task. Here’s how: const text = 'abcdef'; const editedText = text.slice(1); //'bcdef' The slice() method takes two parameters: the starting index and the ending index. In this case, we pass 1 as the starting index to remove the first character....