Basic OLED with rotary encoder Menu for ESP8266/ESP32/Probably others

For either Arduino IDE or PlatformIO.

Note: This is a completely different sketch as of Nov21 as I decided to start again and create a version which is none blocking.
The old version oldVersion.ino is easier to use but will stop everything else whilst waiting for user input etc.

A simple to use, cheap to build and simple to wire menu system using a small oled display and a rotary encoder. I created it so I can quickly and easily add an oLed menu to any new projects, as you can see it only requires 5 wires (plus power).
Uses libraries: Adafruit_SSD1306 and Adafruit_GFX_Library

It gives basic menus, the ability to enter a numerical value or choose from a list.

The sketch uses the cheap 128x64 oled displays but the settings can be changed to work with different size displays.
I am very impressed with these displays, they are cheap, easy to use and despite being small they are still easy to read.
Note: I have seen reports of them being easily damaged by static and I have had one fail which could have been for this reason, I think it best to be careful of this when using one on a breadboard etc, they seem ok once installed in a project.
If you have any poor connections (especially to the rotary encoder) this can result in garbage being displayed which can make you think there is a fault with the display.

If you are new to the esp8266 using one of these OLED displays would be a very good project for you to try.
earch ebay for "SSD1306 i2c" and you should be able to pick up an oled display like the one in the picture above for around £3. Search for "ky-040" for a rotary encoder for around £1.

You can try it out on this online emulation: https://wokwi.com/arduino/projects/323967017900048980

BTW - I have incorporated all this in to my basicWebserver starting point sketch which may be of interest: https://github.com/alanesq/BasicWebserver
Even if you do not use BasicWebserver, this version may be easier to include in your own projects as you just have to include oled.h and add a single line to your setup and loop.

for more oled info see: https://randomnerdtutorials.com/guide-for-oled-display-with-arduino/

Note: I had a lot of trouble finding some code which would work reliably with a rotary encoder (i.e. the interupt section) but find this to be very good although this may not be the case with all encoders?
See these videos for more info: https://www.youtube.com/watch?v=b2uUYiGrS5Y

If you have a cnc router there is a Fritzing file in the MISC folder I use for making PCBs which may be of interest. It is in a format which is very basic but it allows me to modify it and create a PCB as quickly as possible.

                                                       https://github.com/alanesq/BasicOLEDMenu