"This is the first of three applications you will build in this class. Come up with a simple application using digital and/or analog input and output to a microcontroller. Make a device that allows a person to control light, sound, or movement using the components you’ve learned about (e.g. LEDs, speakers, servomotors). For some ideas on what you can make, see the Assignments page, Project 1. It’s due in week 5."
Inspiration
This semester, I went to Shanghai NYU Campus to study remotely, it's also my first time to leave hometown(Beijing) and live alone. The weather and climate in Shanghai, which is one of the typical southern cities in China, is very different from Beijing, which located in the north. The biggest difference is Beijing is always windy, while Shanghai is always rainy.
So, I want to create a rain bell to replace the normal wind chimes, representing the weather in Shanghai and helping me to record the memories in Shanghai.
Final Work
Team
Element
Tools
Duration
About
Individual project
Distance sensor / LEDs / Speaker
Arduino
1 week
This is a cloud that can make rain sound. When people put their hands under the cloud, the center of the raindrop, according to the different distances to the cloud, will make different sizes of the rain.
Installation Draft
Version 1
- Input: raining sound
- Output: light, rotating movement
The input of "rain ball" is a sound sensor, it can detect the decibel of sound in the environment, which reflects the size of rain. While the rainy sound reaches a certain level, the "rain ball" will be lit and rotate. Or if the accuracy of the sound sensor is relatively high, the lightness and the rotating speed can be changeable.
Version 2 (Final version)
- Input: users' distance toward rain ball
- Output: light, rotating movement, raining sound
When people approach the "rain ball", it will be lit, rotate and play the raining sound.
Sensor & Material
Paper lampshade reference:
"Art Attack" S1E38 - https://www.bilibili.com/video/BV1ft411D7Kv?p=38
Circuit & Code
Sensor test
HC-SR04
Paper lampshade reference: https://www.youtube.com/watch?v=6F1B_N6LuKw
HC-SR04 can detect the distance from the sensor to the obstacle, using ultrasonic wave. When I test the sensor, the deviation is between 2-3 centimeters.
- Control the servo
1. The distance relates to the degree of servo
In this situation, the HC-SR04 is more like a switch of the servo. Using map() to connect distance with the degree of servo, the precision is relatively low, comparing with the potentiometer. The reason may be the reading of HC-SR04 is constantly refreshing and fluctuates up and down, and the servo needs a certain time to reset.
Next step, I should adjust the delay time, and use if() condition.
Speaker
- Only use speaker to play audio
Library reference: http://highlowtech.org/?p=1963
- Using HR-SR04 to control speaker and led
Others
- Vibration sensor
- LED
- Final test
Fibration & Assemble
Further idea
If space becomes larger and the clouds are enlarged, people will hear the sound of rain when they walk under the clouds, the sense of immersion will be stronger.