This is an App developed in Flutter to set your desired colour on Neopixel ring from a mobile App. Circuit is done as shown in the following diagram.

Download the NeoPixelColorPicker library from the following link. Unzip and copy the downloaded library to your Arduino libraries folder.

NeoPixelColorPickerDownload

Restart the Arduino software and open the example program from File ->

16-bit shift register module will help you to create 16 digital outputs from only 3 digital outputs of NodeMCU. Circuit is done as shown in the diagram. Upload the following program to your NodeMCU.

/*
Shift Register Example
Turning on the outputs of a 74HC595 using an array

Hardware:
* 74HC595 shift register
* LEDs attached to each of the outputs of the shift register

*/

//Pin connected to ST_CP (12) of 74HC595
int latchPin = 0;

A temperature monitoring system which will turn ON a device such as cooling fan, when the temperature is increased above an upper threshold. Similarly, device will be turned OFF when the temperature is decreased below lower threshold. In between lower threshold and upper threshold, device will continue its state. Circuit is done as shown in the following diagram.

Download the TemperatureMonitorAndDeviceControl library from the following link.

TemperatureMonitorAndDeviceControl-newDownload

Unzip and copy the downloaded library to Arduino libraries folder.