programming chelahmy

ESP8266 started with terrible documentation. Yet for a cheap-and-tiny WiFi module, people hacked around it, added code to it, and manipulated its extra I/O pins to make it do more than it was originally designed for which is a WiFi module to be controlled by an external processor via a serial interface with AT commands in an embedded system. Why extend it to external microcontrollers or microprocessors when it has its own powerful 32-bit processor and plenty of flash memories? ESP8266 has many uses and people created many quick-to-used boards for it such as D1 . No, we don't have to limit ourselves to a particular board. People also created various SDKs for the module and flooded the Internet with incompatible documentations. This is a bitter-sweet situation. Now, we have to assemble our own tool's stack. Espressif Systems, the founder of ESP8266, has a catalog of documentation . They are now proactive to the world community. This is a collection of programming notes ar...

This is an update from my earlier post on the same subject for more than a year ago. The SSL certification is the same but the process has changed. Getting free SSL certificates from Let's Encrypt is a multi steps process. Sites like SSL for Free and ZeroSSL  make it simpler. However, they want to verify that you have the control over the domain where the free SSL certificate is for. They want you to create TXT records in the DNS server that hosts your domain. They will give the details of the TXT records for you to enter. Then they will query the DNS server for the TXT records. If the records are the same then you are verified to have the control over the domain, and they will create the certificate for you. They just create the certificate. You have to install it in your hosting server. I was getting the free SSL certificate for my https://cryptobubbles.club from Let's Encrypt. In fact I wanted to have HTTPS for https://answering.cryptobubbles.club because I want...

You want to write a message to a friend. But you don't want to leave any trail leading to her. It is important that your message does not include her address. You have to leave your message at a secret place so that she can pick it up later. I have created a secret messaging place  Blindtalk.net . As a software developer I cannot run away from cryptocurrency. I studied Bitcoin's whitepaper and its source code. Being so serious about it I managed to extract Bitcoin's message verification code into a standalone library. While many people are focusing too much on the blockchain I'm focusing on the signing algorithm. Cryptocurrency leads me to Blindtalk. But I'm not using Bitcoin or the signing algorithm. Instead, I'm using the Waves platform. I've created Blindtalk token based on Waves, which is the easiest part. Blindtalk is a repository where the senders post messages and the receivers search for them. But it is not a regular posting. A sender has ...

An update to this post can be found here . Shared hosting is still the easiest and cheapest for those who do LAMP. And now if the hosting uses cPanel then it can host your domains with free SSL certificates. You can get free SSL certificates from Let's Encrypt . And you can get them faster from SSL For Free . Let's go to the  SSL For Free  website. Your domains will be running on free SSL certificates by following these three steps. Enter your domain names in the field shown on the front page of the site, and click Create Fre e SSL Ceritificate . The first step is to verify your domain names. You will be given 3 options: Automatic FTP Verification , Manual Verification , and Manual Verification (DNS) . I prefer the second option to the others,  Manual Verification, because it is non intrusive and I don't have to give away any of my password. The verification is required by SSL For Free to ensure that you truly own the domain names and have a host for each o...

Programming does not getting easier. I used to put my code for a specific process in a single file, and perhaps in a single function declaration. When event driven programming arrived, the code was sliced by events. Now, application frameworks demand that a code is sliced into many files and functions. A web application uses multiple frameworks which make code slicing more pervasive. I was inspecting ember.js for a browser-based application framework. Ember.js uses jquery which is a library that I use to simplify javascript programming. Ember.js itself is a MVC framework. Look at the ember.js ' Getting Started ' if you want to see what I meant by code slicing. However, I was writing this post because of Laravel , yet another application framework for the server-side. Ember.js needs to talk to a server for centralized storage. To be specific, I needed a REST server for my ember.js application. Laravel seemed to be a good candidate. Laravel itself was another MVC framework. ...

Geographical Information System (GIS) was designed for engineers. That was good because engineers always work with standards which make interfaces open. Web Map Service (WMS) is one of the open interface standards. WMS focuses on maps portrayal via the Internet. A WMS client will request map graphics from the server which acquires, stores and prepares the maps using GIS back ends. A WMS server can be a full blown GIS engine or it can just be a gateway for other GIS engine. Due to the GIS engineering perspective, many GIS implementation was done by hardcore  programmers who work with C/C++ or Java programming languages. The legacy survives till today. The choice of programming language determines the type of server the GIS requires. Unfortunately, most GIS implementations only work with dedicated servers which incur high operating cost. A dedicated server need a special work force to overlook on the daily operation. We have to be realistic if we want to bring GIS into the ...

Drupal Commerce Kickstart is an all-in-one profile for setting up shopping website or e-shop. Drupal Commerce is built according to the Drupal way. Drupal Commerce is modular and extendable, is based on entities and fields, uses views and taxonomy extensively, and simplifies administrative pages with intuitive menus to ease shop owners. However, before you can start with Drupal commerce you must first be proficient with the Drupal way. You will not be able to administer your shop if you do not know how Drupal works. You need to get yourself up and running with those Drupal thingy such as entity, field, node, views, taxonomy, menu, module, etc. On top of all that, please take note that Dupal Commerce documentation is very much a work in progress. Terminology in Drupal can be very confusing. Drupal Commerce adds to the confusion further. You could not have any other way but to learn the actual meaning of all the terms. Never assume anything. Let's start with the  product  ...