In many IoT Applications we monitor sensor data and we want to display it in wab page. Web page requires frequent refresh to get the update from ESP32. To solve this problem you have two options, first is refresh page with HTML Tag: ex. refresh at every 30 seconds.
<meta http-equiv=”refresh” content=”30″>
Disadvantage of using HTML refresh tag is, it flickers the screen and loads complete page again and again.
Tools you need
only ESP32, Laptop and USB cable
What you will learn?
- ESP32 Ajax web page to display and update sensor data without refresh.
- Getting data from ESP32 without page refresh and update it in web page dynamically. such as ADC values or temperature readings.
Continue reading Web server on ESP32: How to update and display sensor values?
ThingSpeak™ is an IoT analytics cloud platform service that allows you to aggregate, visualize and analyze live data streams in the cloud. ThingSpeak provides instant visualizations of data posted by ESP8266 to ThingSpeak. ThingSpeak is often used for prototyping and proof of concept IoT systems that require analytics.
In this tutorial, We will learn following thinds
- How to Configuring ThingSpeak Cloud server Account ?
- How to program ESP8266 to upload sensor data ?
Continue reading Thing Speak ESP8266
Sound Level Measurement
Using sound sensor we detect ambient sound. This board along with the microphone, has a small built-in amplifier (integrated circuit LM386), because only the microphone would not be able to send signal to Arduino. The connection scheme is very clean, composed of only 3 pins: Vcc, GND and S (signal). In the middle of the plate, there is a potentiometer for sensitivity adjustment. Continue reading Sound Level Measurement using Arduino
The Keyes KY-040 Rotary Encoder
The Keyes KY-040 rotary encoder is a rotary input device (as in knob) that provides an indication of how much the knob has been rotated AND what direction it is rotating in.
It’s a great device for stepper and servo motor control. You could also use it to control devices like digital potentiometers.
Rotary Position Measurement
A rotary or “shaft” encoder is an angular measuring device. It is used to precisely measure rotation of motors or to create wheel controllers (knobs) that can turn infinitely (with no end stop like a potentiometer has). Some of them are also equipped with a pushbutton when you press on the axis (like the ones used for navigation on many music controllers). They come in all kinds of resolutions, from maybe 16 to at least 1024 steps per revolution. Industrial encoders come from 1200PPR to 10000PPR (Pulse per revolution). Continue reading Arduino Rotary Encoder Module KY-040
Water Level Measurement
Here we discuss on low cost continuous liquid level monitoring system based on MPX5010DP differential pressure sensor. Most of the traditional measuring systems were designed and implemented by complicated hardware circuitry. It made the product expensive, with low functionality and with limited precision. With virtual measurement technology, more of the instrument can be substituted by software. Using this approach the cheaper and more versatile measurement system can be developed. The method for obtaining liquid level with one differential pressure sensors MPX5010DP Continue reading Water Level Measurement Using Arduino