Several years ago I began experimenting with Wi-Fi using modules based upon the ESP8266 family of devices manufactured by Espressif Systems in Shanghai. They are microcontroller chips with built-in 2.4GHz Wi-Fi capability. Development boards using these chips are readily available at very low cost from many different suppliers. At first I used the basic ESP8266-01 incorporating the ESP8266EX chip, and then progressed to boards with more functionality ( I/O, serial comms, ADC etc ) i.e., the NodeMCU-12E using the ESP8266MOD. I was thinking about some IoT ( Internet of Things ) applications. Although I made some gadgets, nothing was actually being controlled remotely. Eventually I moved on to other activities.
However, my interest in this topic returned recently after discovering the successor to the ESP8266, namely the ESP32, ( 32bit, 240MHz clock & more memory ), with both built-in Wi-Fi and Bluetooth ( classic Bluetooth & Bluetooth Low Energy, BLE, server & client ) capability; also development boards incorporating the ESP32 such as the NodeMCU-32S and some others including a video camera ( ESP32-CAM ) or an OLED display ( Heltec WiFi Kit 32 ). All these remarkable devices cost only a few dollars.
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| My collection of Wi-Fi & Bluetooth development modules |
In the above image, left to right :-
NodeMCU-12E, Wi-Fi only.
NodeMCU-32S, Wi-Fi and Bluetooth.
WiFi Kit 32, Wi-Fi and Bluetooth, 128 x 64 px OLED display.
ESP32-CAM, Wi-Fi and Bluetooth, 2Mpx video camera, 4GB uSD card slot.
ESP8266-01, Wi-Fi only.
Perhaps I'll make a BLE server to notify a value from an unusual sensor; e.g., air quality, charged particles, UV, magnetic field. ( Obviously for my personal experimental use in my private capacity as a hobbyist. )
( I tweeted updates to this post on 5 August 2020 and 12 August 2020. Click on the link on the left ).
