Doorbell
This doorbell experiment consists of a button and passive buzzer. Passive buzzers emit seven different tones when pressed, so you can learn how to change your own home doorbell.
Room Temperture Meter
In this project, we made an indoor thermometer using a thermistor and LCD1602 modules. Through the formula conversion to the Celsius temperature display on the I2C LCD1602 Module, thermal resistance senses the change in ambient temperature.
Rainbow LEDs
There are 8 RGB LEDs in this WS2812 RGB 8 LED Strip. All LEDs can be controlled with just one pin. The RGB LEDs are equipped with WS2812 chips, which can be controlled independently. Displays are capable of 256 levels of brightness and 16,777,216 colors.