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Showing posts from May, 2019

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Arduino FreeRTOS Mutex Examples

In this section, we will explain using an example to demonstrate mutexes in Arduino using freeRTOSThere are two freeRTOS Mutex examples in this tutorial, the first example demands some hardware (LCD) While the second does not need any hardware, you can try out both if you have the resources.

In the last tutorial, we considered in detail: semaphores and mutexes and we also established the difference between binary semaphores and mutexes.
Just for a review:Recall that a mutex is a locking mechanism that implements the take and gives functionality in itself, unlike a binary semaphore. See this tutorial if you have not before continuing.
Example 1: Protecting the LCD Resource Using Mutex in freeRTOS
Program Description

In this program, we Demonstrated the use a 16x2 LCD display to implement a mutex.

The LiquidCrystal library works with all LCD displays that are compatible with the Hitachi HD44780 driver. you can usually tell them by their 16-pin interface.

THE CIRCUIT

* LCD RS pin to digital…

Digital Systems and Stability Analysis using Jury's Stability Test

In this post, we will be introducing digital control systems, their advantages, and disadvantages, we will also perform a comparison between digital and analog control systems. Then we will proceed to sampling and Shannons sampling theorem and how it is applied practically, we will also see some sampling circuits and review Zero Order Hold DAC. Finally, we will look into analysis of the response of digital systems using difference equations and Stability analysis of Digital Control Systems using Jury's stability criterion, we will explain how to plot the Jury's table using an example to illustrate the process and how to make statements about the stability of the system.

So many theories and analytical tools exist in classical analog control system analysis, however, due to the shifts in technology, control algorithms are now been implemented using digital systems and microprocessor-based controllers, this is because of its numerous advantages, recent studies have shifted focus…

Understanding Real Time Operating Systems [R.T.O.S]

It is very important for computer science students and electronic and computer engineers to understand real time operating systems. In this post, a solid background of RTOS will be established and you will be able to understand the basics and features of a real time OS.

Real time operating systems sounds strange at a glance, you can immediately suggest that it is an operating system that responds in real time. In an RTOS, tasks are given a deadline to complete, missing a deadline can cause undesired to catastrophic damages.

How then is it different from a General Purpose Operating system?

Where are they applied?

What features makes a given Operating system an RTOS?

Is there a way I can implement RTOS in my project if yes, how?

In this article, I will endeavor to answer all the questions listed above. If you would like to go through the history of RTOS, Wikipedia presents a good summary here.
What is an RTOS?
Let’s define an Operating system first.

An operating system is a system progra…

Procedure for Electricity Generation in a power plant

The Procedure for Electricity generation in a thermal Power plant is a rather intricate and continuous process that utilizes many engineering applications, equipment, and control mechanisms so as to efficiently produce the required output. It encompasses the production and purification of feedwater, demineralization of the feedwater, steam generation process and the efficient use of the steam by the turbines for power generation.

Basing this post on the engineering training received from Nigerian's biggest Power Plant (Egbin), The Electrical Power generation process involves the following stages:

Deep-well Water Production Process.
Water Treatment Process.
Demineralization Process.
Steam Generation Process (Boiler).
Steam Work Process (Turbine & Generator).
Water Production and Treatment Process
The Deep Well Water: The Deep-well can be said to be an industrial-sized borehole. The Deep-well is preferably used over the conventional stream or water body because it requires less modifi…

Basic Overview of the Internet of Things (IoT) and its Challenges

Understanding the Internet of things can be a very exciteful journey, in this post, we are going to fully explore the topics of interest. First, we define the term internet of things, then see some popular IoT examples, IoT companies, protocols used in IoT Applications and what the scope of IoT is.

Internet of things is a novel and fast growing technology in the world of information, communication and computing technology that soon will be affecting and structuring the lives and living standards of man on a global scale. Despise this wonderful potential, it has great challenges that if not handled effectively can be catastrophic. This article concludes by evaluating these challenges.
What is ( IoT )Internet of Things?
There is currently no agreed definition of the term internet of things, however, what all definitions have in common is the idea that the previous version of the Internet was about data created by people, while the internet of things is about data created by things. The b…

Working Principle of a Gas Turbine Generator

How do Gas Turbine Generators work? If the steam turbine generator uses steam, do gas turbines use gas? In trying to understand the working principle of a gas turbine generator, these were the questions I asked during the course of my training. I was privileged to work with Korean engineers and experienced gas turbine specialists during my training, I have documented my experiences in this series be sure to see it.

In this post, I will be educating us on the fundamental principles of operation of a gas turbine generator or better still the basic working principle of a gas turbine power plant and then the comparison between a steam turbine and a gas turbine, the advantages and disadvantages.

The concept described below contains some specific information applicable to the generator I worked with. However, it can be applied to any other Gas Turbine generator except that values may be changed.
Working Principle of a Gas Turbine Generator
In an electricity generating plant, it is not unusua…

Internet: Overview and Basic Concepts

The term “internet” is currently a very common term in our present day lexicon and not too many people try to really consider what it really is. In this post, we will be learning about the internet. How it came about and how it works.

In this article, we will be considering some basic sections of this large scale network called the internet. The Internet of things redirects here.
What is the internet?
The internet commonly called the internetworking of networks is a high capacity public switched network that is operated by a group called the Internet Service Providers.

Internet Service Providers
These are the group that makes the internet available for people to use, they are broadly divided into two groups:
1. Backbone Operators
2. Internet Resellers
The internet comprises of hundreds of backbone networks.

Backbone Operators: The backbone operators are the big guys on the internet, they maintain the backbone networks.

A backbone network is a high capacity packet switched network that is made u…

Understanding the operation of I2C Bus

I2C pronounced as "I squared C" OR "I two C" is an acronym for Inter-Integrated Circuit Bus. It is a serial synchronous bus which we will be considering in this post. It is a very unique bus with a two-wire interface and can connect to about 127 slaves for a 7-bit address system, it can use 7-bit or 10-bit for slave addressing.
I2C Bus
I2C  is a serial and synchronous two-wire interface used to interface low-speed devices and peripherals like the EEPROMs, A/D and D/A converters, sensor networks, other I/O  to microcontrollers in embedded systems. It was invented by Philips and popular amongst all major IC manufacturers.  The two wires in I2C bus are:

SCLK: For the serial clock signal
SDA: Serial Data line for transfer of bits (data and address and control information)
I2C Features

Two-wire interface
Synchronous: All parties involved in the communication are tied to the same clock
Uses 7 bit or 10-bit slave address
Can address up to 256 peripherals in a 7-bit address mode
Us…

Feed Water Heaters: Relevance in a Power Plant

In this post, we will be considering the relevance of feedwater heaters in a typical power plant. What are they? Why should there be feed water heaters? What advantages do they add to the system? What happens when they are not present?

Feed water is the working fluid used for power production. The purified water that is sent into the boiler for heating and for the steam work process in the turbine after a series of treatments.
What are feedwater heaters?
Feedwater heaters are major pieces of equipment or passive machinery that help increase the temperature of the feedwater before introducing it into the hot well, to accurately understand this, you will need to go through the post on power generating process in a power plant.

Whenever we talk about heaters, three parameters are important.

Heat source
What is being heated
Heat transfer method
The working principle of feedwater heaters is basic, they work on the principle of heat conduction, heat is taken from the high-temperature extractio…

My Experience at the Largest Thermal Power Plant (1.32GW) in Africa

In the course of my studies as an electrical and electronic engineering student, I was privileged to undertake a training program in Egbin Power Plc, it is arguably the largest single thermal power generating plant in black Africa with an installed capacity of 1320MW which is currently about to be extended.

It was a very insightful experience and I learned so much about the power industry.

However, for the sake of this post, I am drafting this to actually introduce the major concepts I learned first hand in the power plant and you will enjoy the series if you have a theoretical background. If you don't, it will spur up your studies when you are being introduced to the theories of how it works.

I will be breaking down this series into the following:

How power is generated in  a thermal power plant: In this post, we provided a walk through to how power is generated in a steam power plant, from the purification of water - citing the processes common bore-hole drilled water pass throug…

Synchronization and interconnection of Generating stations

Ever wondered how different generating stations are interconnected together for the production and transmission of electricity, and still perform in harmony as one single entity, before a generating station or  a generator can be connected together with another, some conditions must be met, in this article, we will be looking into these conditions and how it is carried out in a typical power industry.
Synchronization and Interconnection of Generators and Generating Stations.
The concept of synchronization is not only applied to grid connections, even in the bus transfers. To interconnect two or more ac power sources, the parties involved must have the same:

Frequency
Phase Sequence
Voltage
When all these parameters are the same, they can be connected together safely.

So how is this done in a power station?

Synchronization in a power industry can either take place manually or automatically. In the manual mode, the operator checks to ensure that the parameters are the same and then closes t…

Field Flashing of a Generator and Excitation Mechanism

This is part of my Egbin Thermal Power plant series and it is really interesting getting to understand how field flashing and excitation of the generator takes place. I am creating this content tailored towards a steam turbine generator. The concept is valid for all kinds of generators.

Alright, let me first introduce what field flashing is and then we will look at how it is done in a typical thermal plant.
The concept of Field Flashing
For electricity to be induced in a coil, according to the Faraday's Law of Electromagnetic induction, there are two requirements: The coil/conductor and the varying magnetic field. Such that whenever the coil is placed in a varying magnetic field, an emf (Electro Motive force) is induced in the coil.


Usually, in small dc motors, this magnetic field is generated by permanent magnets, however, in large generators and generating stations, an electromagnet (a soft iron core possessing a  magnetic field by the passage of electric current through it) is …