Blog language: en.

Basic information about ESP32

Blog language: en.

Introduction to ESP32

The ESP32 is a powerful microcontroller that has gained popularity in the field of embedded systems. It is known for its versatility and capabilities, making it a popular choice among developers and hobbyists alike. With its dual-core processor and built-in Wi-Fi and Bluetooth capabilities, the ESP32 offers a wide range of features that make it ideal for various applications.

Features of ESP32

One of the key features of the ESP32 is its dual-core processor, which allows for multitasking and improved performance. Additionally, the built-in Wi-Fi and Bluetooth capabilities make it easy to connect the ESP32 to other devices and networks. The ESP32 also offers a variety of GPIO pins, analog-to-digital converters, and other hardware features that make it suitable for a wide range of projects.

Applications of ESP32

The ESP32 is used in a variety of applications, including home automation, IoT devices, robotics, and more. Its low power consumption and connectivity options make it ideal for projects that require wireless communication and remote monitoring. Whether you are a beginner or an experienced developer, the ESP32 provides a versatile platform for building innovative projects.

Getting started with ESP32

To get started with the ESP32, you will need a development board, such as the popular ESP32 DevKit. You can program the ESP32 using the Arduino IDE or other development environments, making it easy to get started with your projects. There are plenty of resources available online to help you learn more about programming and using the ESP32 effectively.

Troubleshooting common issues

Despite its many advantages, the ESP32 may encounter some common issues that you should be aware of. One common problem is connectivity issues with Wi-Fi or Bluetooth, which can often be resolved by updating the firmware or checking the connections. Additionally, power-related issues or software bugs can also cause problems with the ESP32. By familiarizing yourself with these common issues and troubleshooting steps, you can ensure a smooth development process with the ESP32.

Remember, the ESP32 is a versatile and powerful microcontroller that can be used in a wide range of projects. Whether you are a beginner or an experienced developer, the ESP32 offers a wealth of features and capabilities to help you bring your ideas to life. Start exploring the world of ESP32 today and unlock the potential of this innovative platform.

Overview of FreePBX

FreePBX is a powerful open-source graphical user interface that manages Asterisk, the leading open-source telephony engine. It provides a user-friendly way to configure and manage your PBX system efficiently. With a wide range of features and customization options, FreePBX is a popular choice for businesses looking to set up a robust and scalable communication system.

Setting up Intercom Feature in FreePBX

Setting up the intercom feature in FreePBX is essential for seamless communication within your organization. Intercom allows users to make announcements or have instant conversations without the need to dial a specific extension. To configure the intercom feature in FreePBX, navigate to the settings menu and enable the intercom module. You can then assign permissions and define the intercom extension range for easy access.

Configuring Extensions for Intercom System

To ensure smooth operation of the intercom system in FreePBX, it is crucial to configure extensions properly. Each user or device should have a unique extension assigned to them, allowing them to send and receive intercom calls seamlessly. By setting up extensions correctly, you can streamline communication and improve productivity in your organization.

Creating Intercom Groups in FreePBX

Creating intercom groups in FreePBX enables you to categorize users based on their departments or locations. This feature allows you to broadcast messages to specific groups of users, making it easier to reach the right people quickly. By creating intercom groups, you can enhance collaboration and ensure that important announcements are relayed to the relevant individuals efficiently.

Testing and Troubleshooting Intercom Telephone System in FreePBX

Once you have set up the intercom telephone system in FreePBX, it is essential to test its functionality to ensure that everything is working as intended. Conducting test calls and scenarios will help you identify any potential issues and troubleshoot them promptly. Common troubleshooting steps include checking network connectivity, verifying configurations, and ensuring that all devices are properly connected.

Introduction

In this blog, we will dive into the world of containerization with a focus on two powerful tools: Docker and Podman. Containerization has revolutionized the way we develop, deploy, and manage applications, providing a lightweight and scalable approach. Let’s explore the intricacies of Docker and Podman and understand how they can benefit your projects.

Understanding Docker

Docker Overview: Docker is an open-source platform that enables developers to automate the deployment of applications inside containers. Containers are lightweight, isolated environments that package an application with its dependencies, making them portable and easy to deploy across different systems.

Features of Docker: Docker provides a range of powerful features that enhance the containerization experience. These include:

• Efficient resource utilization
• Isolation of applications
• Easy scalability
• Version control and image management
• Networking capabilities

Docker Architecture: Docker follows a client-server architecture, where the Docker client communicates with the Docker daemon to build, run, and manage containers. The architecture consists of various components, including the Docker Engine, Docker Images, and Docker Hub, which is a repository for Docker images.

Exploring Podman

Podman Overview: Podman, on the other hand, is an alternative container engine that provides a similar experience to Docker but without the need for a daemon. It offers a daemonless and rootless container engine, making it ideal for environments where security and isolation are paramount.

Key Differences between Docker and Podman: While Docker and Podman share many similarities, there are a few key differences worth noting. Unlike Docker, Podman does not require a separate daemon, allowing users to run containers as non-root. Additionally, Podman utilizes the Container Runtime Interface (CRI) to interact with various container runtimes, providing flexibility and compatibility with different tools.

Benefits of Using Podman: Podman brings several benefits to the table, such as enhanced security, improved resource management, and simplified container management. With Podman, developers can enjoy the benefits of containerization without sacrificing security or needing root access.

Use Cases for Docker and Podman

Containerization in Development Environments: Docker and Podman are valuable tools for creating consistent development environments. By packaging applications and their dependencies into containers, developers can ensure that their code runs consistently across different machines, reducing the “it works on my machine” problem.

Container Orchestration: Both Docker and Podman excel in container orchestration, allowing developers to manage and scale containers across multiple hosts. Docker provides a robust solution with its native orchestrator, Docker Swarm, while Podman integrates seamlessly with popular orchestration platforms like Kubernetes.

Continuous Integration and Deployment: Docker and Podman play a crucial role in CI/CD pipelines, enabling developers to package applications into containers and deploy them efficiently. By encapsulating the application and its dependencies, containers simplify the deployment process and promote consistent and reliable software delivery.

Conclusion

In conclusion, Docker and Podman are powerful tools that have revolutionized the way we develop, deploy, and manage applications. While Docker remains the go-to choice for many, Podman offers a compelling alternative with its daemonless and rootless approach. Whether you choose Docker or Podman, containerization brings numerous benefits, such as improved scalability, portability, and security. Stay tuned for more exciting developments in the world of containerization!

Since the early 1990s, there has been a constant that is happening rapidly, at least on the consumer end. There were initially websites that were used. There were companies working on software on the outskirts. However, as the smartphone market grew, there was a lot going on. There was a lot of back and forth in order to automate the entire process of implementing and conceiving app features. App features that can provide recommendations based on acute data analysis are also available.

These systems could recommend products to you in the same way that your best friend could. Despite the fact that different programming languages were used for its implementation, Python became popular and is still one of the top contenders in the field of machine learning.

The language interpreters are available for a variety of operating systems. Python’s resources are managed and directed by a non-profit organisation known as the Python Software Foundation. Also, when we talk about development, it is done by a global community of developers. They maintain CPython, an open-source reference implementation of the Python programming language.

What are the reasons for its widespread acceptance?

👉 Simple to Use
Python syntax is quite simple, and Python has chosen to eliminate more trivial issues.
When compared to other languages, the language can save you a lot of lines. It is also highly effective and makes complex software development much easier.

👉 Broad Library and Framework Support
Python’s libraries and frameworks are one of the main reasons it is preferred over other languages. All of these can be used to help with development.

👉 Neural networks
It is a subset of machine learning with a distinct application. These learning systems are inspired by the brains of humans and animals. In this case, the machine learns by acquiring task-oriented rules. Image recognition is one of the best examples of this. Python provides a number of tools to assist you with this.

👉 Community and Support
There is no doubt that the language has strong support, as it is backed by one of the best tech companies, Google. Aside from that, there are numerous forums, websites, and video tutorials where Python is discussed and taught. This creates a much more welcoming environment in which the language can be taken seriously.

CBC

Cipher Block Chaining (significantly known as CBC) is a mode of encryption used in block ciphers. It is an advanced form of block cipher encryption and also more secured when compared to ECB. This mode uses a random block of bytes known as Initialization Vector (IV) to ensure randomization of encryption. It is important to use IV only once to ensure security.

Encryption:

CBC is one of the most popularly used mode of encryption in AES. Unlike in ECB mode, in CBC mode, encryption of one block of plaintext is dependent on the previous block. Each block of plaintext is XORed with the previous block of ciphertext, for the first block it is XORed with IV(16 bytes) and then sent through the whitebox. So, change in one single byte changes the entire ciphertext. Hence, eavesdropper can’t attack the data easily.

 C[i] = E(Pt[i]  ^ C[i-1])
 C[1] = E(Pt[i] ^ IV)

Advantages over CBC:

Dependency of one block encryption over the previous one ensures that traces of similar data aren’t left behind, whereas in ECB, change in a byte changes only the corresponding block i.e encrypting 2 blocks that contain same plaintext gives the same ciphertext in ECB. This gives a pattern to the attacker whereas in CBC this doesn’t happen.

Decryption:

Decryption is just the reverse. Each block of ciphertext is sent through the whitebox and then XORed with the previous block of ciphertext to recover the plaintext. So, one need not decrypt the previous block to get the required block of plaintext.

Pt[i] = D(C[i]) ^ C[i-1]
Pt[1] = D(C[1]) ^ IV

Attacks possible:

IV reusing might lead to leakage of information regarding the first block of plaintext. However the rest are unaffected. It is also vulnerable to attacks like bit flipping attack, padding oracle attack etc.

ECB

What is ECB?

Electronic Code Book (or ECB) mode of encryption is the simplest of all the modes of encryption. This mode of encryption is the first one which was implemented under AES. But, later we’ll analyze the plus and the minus features of this mode because of which it’s popularity is reduced. Now, we’ll see how is ECB mode of encryption is applied to any of the above described data encryption algorithm.

How is the encryption done?

In this mode of encryption the plain text is divided into different blocks of equal block sizes. Then each block is encrypted in parallel.

As you can see the different blocks of the plain text are encrypted separately using any of the algorithms described above (Like AES, DES) The parallel encryption of each block is the basic essence of the ECB mode.

How is decryption done?

Similar to the encryption the cipher text is divided into different blocks depending upon the block size. Thus, decryption is done on each block, at the same time, using the algorithm with which it was encrypted.

Advantages of ECB

The advantage of ECB mode of encryption over others is that here each block is encrypted separately. Therefore, if any of the block goes corrupted it doesn’t affect the rest of the encryption. Also, because of this feature a multiprocessor can simultaneously encrypt different blocks thus saving time.

Disadvantages of ECB

The main disadvantage of ECB is that the similar part of the plain text are encrypted with the same key to the same cipher text. That is, if in block 1 the plain text character ‘e’ is encrypted as ‘f’ in block 2 also if there’s ‘e’ in the plain text it would be encrypted as ‘f’. Also, the blocks of cipher text can be rearranged which when decrypted would give deranged output which is undesirable.

Vulnerabilities of ECB

The most common attack on ECB is the “ECB byte at a time attack” which exploits the loophole in ECB encryption which would give the same cipher text when applied to the similar characters of plain text.

IstSOS is Free and Open Source Sensor Observation Service Data Management System (OGC SOS server implementation) written in Python. istSOS allows for managing and dispatch observations from monitoring sensors according to the Sensor Observation Service standard. It provides a Graphical user Interface that allows for easing the daily operations and a RESTFull Web api for automatizing administration procedures. istSOS is released under the GPL License, and runs on all major platforms (Windows, Linux, Mac OS X), even though it has been used in production in linux environment only.

Main Features

• Offer your data according to the Sensor Observation Service standard from Open Geospatial Consortium.
• Administer your sensors and your data with a comfortable interface.
• Use a complete API for accessing functionalities to makes it easy for new clients to use istSOS application.
• Get notified trough mail, twitter or other social when your sensor data met specific conditions.

How to Install (On Ubuntu 18.04)

sudo dpkg -i python3-istsos_2.4.0-RC4.deb;sudo apt-get -f -y install

A fantastic feature of any WiFi-enabled microcontroller like ESP8266 NodeMCU is the ability to update its firmware wirelessly. This is known as Over-The-Air (OTA) programming.

The OTA programming allows updating/uploading a new program to ESP8266 using Wi-Fi instead of requiring the user to connect the ESP8266 to a computer via USB to perform the update.

OTA functionality is extremely useful in case of no physical access to the ESP module. It helps reduce the amount of time spent for updating each ESP module at the time of maintenance.

One important feature of OTA is that one central location can send an update to multiple ESPs sharing same network.

The only disadvantage is that you have to add an extra code for OTA with every sketch you upload, so that you’re able to use OTA in the next update.

The factory image in ESP8266 doesn’t have an OTA Upgrade capability. So, you need to load the OTA firmware on the ESP8266 through serial interface first.

It’s a mandatory step to initially update the firmware, so that you’re able to do the next updates/uploads over-the-air.

The ESP8266 add-on for the Arduino IDE comes with a OTA library & BasicOTA example. You can access it through File > Examples > ArduinoOTA > BasicOTA.

The following code should load. But, before you head for uploading the sketch, you need to make some changes to make it work for you. You need to modify the following two variables with your network credentials, so that ESP8266 can establish a connection with existing network.

const char* ssid = "..........";
const char* password = "..........";

Once you are done, go ahead and upload the sketch.

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

const char* ssid = "..........";
const char* password = "..........";

void setup() {
  Serial.begin(115200);
  Serial.println("Booting NodeMCU");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("Sorry, Connection Failed! Rebooting NodeMCU...");
    delay(5000);
    ESP.restart();
  }
  ArduinoOTA.onStart([]() {
    String type;
    if (ArduinoOTA.getCommand() == U_FLASH)
      type = "sketch";
    else 
      type = "filesystem";

    Serial.println("Start updating " + type);
  });
  ArduinoOTA.onEnd([]() {
    Serial.println("\nEnd");
  });
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  });
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) Serial.println("Auth Failed");
    else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
    else if (error == OTA_CONNECT_ERROR) Serial.println("Connecting Failed");
    else if (error == OTA_RECEIVE_ERROR) Serial.println("Receiving Failed");
    else if (error == OTA_END_ERROR) Serial.println("End Failed");
  });
  ArduinoOTA.begin();
  Serial.println("Ready");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  ArduinoOTA.handle();
}

Now, open the Serial Monitor at a baud rate of 115200. And press the RST button on ESP8266. If everything is OK, it will output the dynamic IP address obtained from your router. Note it down.

Upload New Sketch Over-The-Air

Now, let’s upload a new sketch over-the-air.

Remember! you need to add the code for OTA in every sketch you upload. Otherwise, you’ll loose OTA capability and will not be able to do next uploads over-the-air. So, it’s recommended to modify the above code to include your new code.

As an example we will include a simple Blink sketch in the Basic OTA code. Remember to modify the SSID and password variables with your network credentials.

#include <ESP8266WiFi.h>
#include <ESP8266mDNS.h>
#include <WiFiUdp.h>
#include <ArduinoOTA.h>

const char* ssid = "..........";
const char* password = "..........";

//variabls for blinking an LED with Millis
const int led = D0; // ESP8266 Pin to which onboard LED is connected
unsigned long previousMillis = 0;  // will store last time LED was updated
const long interval = 1000;  // interval at which to blink (milliseconds)
int ledState = LOW;  // ledState used to set the LED
void setup() {
pinMode(led, OUTPUT);
    
  Serial.begin(115200);
  Serial.println("Booting NodeMCU");
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.waitForConnectResult() != WL_CONNECTED) {
    Serial.println("Connection Failed! Rebooting NodeMCU...");
    delay(5000);
    ESP.restart();
  }
  ArduinoOTA.onStart([]() {
    String type;
    if (ArduinoOTA.getCommand() == U_FLASH)
      type = "sketch";
    else
      type = "filesystem";

    Serial.println("Start updating " + type);
  });
  ArduinoOTA.onEnd([]() {
    Serial.println("\nEnd");
  });
  ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
    Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
  });
  ArduinoOTA.onError([](ota_error_t error) {
    Serial.printf("Error[%u]: ", error);
    if (error == OTA_AUTH_ERROR) Serial.println("Auth Failed");
    else if (error == OTA_BEGIN_ERROR) Serial.println("Begin Failed");
    else if (error == OTA_CONNECT_ERROR) Serial.println("Connecting Failed");
    else if (error == OTA_RECEIVE_ERROR) Serial.println("Receiving Failed");
    else if (error == OTA_END_ERROR) Serial.println("End Failed");
  });
  ArduinoOTA.begin();
  Serial.println("Ready");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
}

void loop() {
  ArduinoOTA.handle();

  unsigned long currentMillis = millis();
  if (currentMillis - previousMillis >= interval) {

  previousMillis = currentMillis;
  ledState = not(ledState);
  digitalWrite(led,  ledState);
  }
}

Once you copy above sketch to your Arduino IDE, go to Tools > Port option and you should see something like this: esp8266-xxxxxx at your_esp_ip_address If you can’t find it, you may need to restart your IDE.

Select the port and click Upload button. Within a few seconds, the new sketch will be uploaded. And you should see the on-board LED blinking.

Saltwater batteries are not similar to lithium-ion batteries or lead acid batteries for use in portable devices or any automobiles. This is because they can’t hold as much charge in the same size and weight, or putting it another way, they are less energy-dense. But they hold some powerful advantages in applications in which size and weight are less important.

The electrolyte for a saltwater battery is nothing more than — salt water — hence the device’s name comes from it. The anode can be carbon, and the cathode can be a material such as manganese oxide. (Or anode can be copper and cathode can be zinc or aluminum).

With no hazardous materials in their construction, unlike lithium-ion batteries, they are non-toxic and they cannot explode. There is no need for the complex and troublesome electronic circuitry that every lithium-ion battery needs to ensure that they charge and discharge only within safe parameters. In addition, unlike their lithium-based cousins, saltwater batteries can be more deeply discharged (drained of electrical energy) with no damage to the battery.

The biggest disadvantage of all forms of salt-water batteries is that, to store a given amount of electricity, they are bulkier and heavier than other commercially available batteries. As it turns out, there is one huge potential use for these devices in which that will be no issue at all — smoothing out power from large-scale renewable-energy-generation plants.