ESP8266 Tutorial

Relays in electronics are useful for controlling a high-power load using a smaller-power circuit. For example, an Arduino or PIC running on 5V, controlling a 240VAC light bulb, etc. This is what we have shown in our Arduino relay tutorial. But did you know that there are different types of …

Last time, I featured the 0.96” OLED display and how to use with an Arduino microcontroller. If that screen was too small, you can try upgrading to a slightly larger 1.3” display. This tutorial aims to guide you on how to use the 1.3” OLED with popular microcontroller boards such …

The WeMos D1 Mini is a compact ESP8266 development board with 11 digital I/O pins, one analog input, and built-in WiFi. This guide covers the complete WeMos D1 Mini pinout, including the D0–D8 to ESP8266 GPIO mapping, I2C, SPI, UART, ADC, power and boot pins. After the pinout reference, we'll …

The DHT22 is a temperature and humidity sensor in one package. It is widely used mainly due to its price but also because of it being robust and user-friendly. In this NodeMCU DHT22 interfacing tutorial, I will guide you in creating an IoT-based weather monitoring project with ESP8266.

A Passive Infrared (PIR) sensor is a popular sensor for detecting the presence of a person. This is a type of proximity sensor although you may also call it a motion sensor. This tutorial aims to guide you in using a PIR sensor with your NodeMCU ESP8266 WiFi board.

The ESP8266 has been a blessing to makers who need to connect their Arduino to the Internet on the cheap. In fact, boards like the NodeMCU and WeMos which feature the ESP module have become overly popular.  This is unsurprising given that these boards can replace the Arduino without a …

You can use WiFi with the NodeMCU (ESP8266) even without a WiFi router. All you need to do is create a NodeMCU WiFi Access Point and the device will now act as a WiFi gateway.

Uploading sensor data to web servers is one of the core ideas for Internet of Things (IoT). Such data are often small-sized and are continuously updated over time. And while HTTP performs satisfactorily for simple applications, like how I showed in my NodeMCU web server tutorial, there is a need …

So far, we've been using HTTP in our NodeMCU web servers and while it works, the protocol is not really the best way for sending and receiving small-sized data for IoT applications. In this tutorial, I will introduce you to MQTT using ESP8266.

Last time we managed to display sensor data to a NodeMCU web server. The problem with that code is that we need to refresh the page manually in order to update the sensor value. A better method is to use Ajax (asynchronous javascript and XML) so that we can request …