Hardware

Detailed article on computer hardware parts like RAM, Motherboard, Processor, Graphics card. Hardware also covers topics on hardware of Server, Single Board Computers like Raspberry Pi to Libre Hardware Projects.

Raspberry Pi 3 Vs Raspberry Pi 4 For Dev Works

Raspberry Pi 4 released just a few months back from today. Raspberry Pi 3B+ has not become obsolete. It will be supported for the projects which work well with it. Unless you need the extra RAM for a project, getting a new board will invite to buy or 3D print an enclosure. The port layout of Raspberry Pi 3B+ is different than Pi 4. The more bad news is that - Pi4 gets hotter. Does it play 4K … [Read more...]

Control Multiple AC Appliances With One ESP32 Arduino

The result of this guide will be a local control panel with ESP32, pushbuttons, LED indicators, relays which can control the connected AC appliances by the simple pushbutton press. When connected to Wi-Fi, it will be able to control the thing over the internet with simple HTTP cURL commands. This guide and code can be used for home automation or creating smart power outlet. Single relay version of … [Read more...]

ESP32 Arduino : Multiple MQTT Topic

It is possible to use a single ESP32 to handle multiple relays in your IoT project. We can use MQTT to subscribe or publish multiple topics. A good real-life deployable example of IoT controlled AC appliances is our guide on . In that project, we have two status indicator LEDs and one relay connect to the ESP32. We could control the AC appliance connected with the relay either by pressing a … [Read more...]

How to Control Multiple Relays With Single Arduino ESP32?

One regular reader of this website asked us how we can control multiple relays with single Arduino ESP32? This article will not give any direct answer. This is a theoretical article discussing how multiple channels on MQTT can be created so that we can separate matters like temperature and humidity from a DHT11 sensor. Normally we connect DHT11 with IBM Watson IoT in a raw manner. In our that … [Read more...]

ESP32 Arduino AC Motor Speed Control Module/Circuit

So far, we have shown how to control ON/OFF status of an AC powered appliance with IBM Watson IoT. That guide is important to use HTTP(S) POST request instead of using MQTT. HTTP POST and MQTT has difference of use-case. In this present article, we only restrict ourselves to discussions around ESP32 Arduino AC motor speed control module and circuit. Using an AC appliance for switch ON and … [Read more...]

Influence of the Internet of Things (IoT) on Retail : Part II

This is the second article of this series. In the first part of Influence of the Internet of Things on Retail, we have disccused fundamentals of IoT including the key technologies. When implementing IoT projects in retail, there are a variety of factors to consider. The technological challenges to realize these in everyday business processes are very demanding. For a widespread dissemination, it … [Read more...]

Influence of the Internet of Things (IoT) on Retail : Part I

The Internet of Things (IoT) is evolutionary rather than revolutionary development that will continue to evolve rapidly over the next few years. Apart from the present series, we have Internet of Things in the Smart Home and Wearables and Internet of Things for the readers. The beginning of this evolution by Internet of Things (IoT) dates back to the sixties. At the beginning of the nineties, … [Read more...]

DIY Solder Masking for PCB Making at Home

Solder Mask Protects the Copper Tracing of the PCBs & Gives a Professional Look. Here is About the Solder Masking for DIY PCB Making at Home. Though previous various publications we talked about making PCB at home. These days, there are also flexible PCB mainly for creating connector ribbons with some components. Any kind of PCB better gets a mask. Solder mask is a thin lacquer-like liquid … [Read more...]

Simple Level Shifter With Transistors (3.3V-5V)

Earlier, we talked about the level shifter. Raspberry Pi, ESP32 etc things operate at 3.3v logic whereas, relay modules usually need near 5v TTL logic level. In our guide to control AC appliances over the internet with ESP32, you will notice that directly connecting the relay with ESP32 will not properly work - it will work over the internet but when you'll press the pushbutton, it will go to off … [Read more...]