Title: Touch Adjustable Lighting Design Team Information: Yin Yipeng, Wu Ji Award Information: Third Prize

Competition title: Touch-adjustable lighting design switches modes through touch sensors. When a light touch is detected, it will only switch among the four styles: always on, running horse, running water, and cool; when a long press (more than 1s) is detected, a touch delay turn-off performance will be performed (the brightness will gradually increase, and extinguishes after 3s). When the A1 analog port reads a value greater than 600 (determined by the properties of the photoresistor and series resistance), the animation rate of the first four modes becomes faster (the frame interval changes from 200ms to 80ms).

Demo video: https://www.bilibili.com/video/BV1of4y1v7tZ

Question B

1. Competition question requirements and design plan

1.1 Competition question requirements

Question B. Touch control adjustable lighting design

( 1 ) Use Lichuang EDA to design a running water lamp with touch function ( 5~7 lamps);

( 2 ) The touch switch is used to switch the effect of the running water light: constant light mode, running water light mode, delayed light off mode;

( 3 ) The touch function can be implemented through the touch module; it can also be implemented using photoresistors, grayscale sensors, etc. If touch control is not possible, use buttons to replace this function;

( 4 ) Improved requirements: Different lighting indication effects can be produced through external light, sound, temperature and other parameters.

( 5 )Other play

Other instructions: It is recommended to use the controller design for this question. The controller should be prepared by itself. The necessary interfaces are provided for the controller in the circuit design and connected during physical debugging.

1.2 Overall scheme design

The touch-adjustable lighting project designed by our group consists of two systems. The first part is the running water light system, which is the main body of the light display. The running water lamp is composed of 6 small LED light bulbs. It has a variety of animation modes (including five modes: always on, horse racing, running water, cool, and long press delay). At the same time, the ambient lighting can change the animation playback speed of the running water lamp.

The second part is the touch system, which controls signal input through the touch sensor, and then determines the LED animation mode and delay timing through algorithms . This is the key to mode switching.

1.3 Mode conversion design

For example, if the i -th LED is numbered 1-6 in sequence , and the array a ₁ a ₂ a ₃ a ₄ a ₅ a ₆ is used to represent their on and off conditions ( 0 means off, 1 means on), then:

(1)    Always on: 111111 ;

(2)    Horse racing: 000000,100000,010000,001000,000100,000010,000001 ;

(3)    Running water: 000000,100000,110000,111000,111100,111110,111111,111110,111100,111000,110000,100000,

(4)    Cool: 101010, 010101 ;

(5)    Long press to delay.

Switch modes via touch sensor. When a light touch is detected, it will only switch between the four styles of always on, running, running water, and cool; when a long press (more than 1s ) is detected, a touch delay turn-off performance will be performed (the brightness will gradually increase, and the extinguishes after 3s ). When the A1 analog port reads a value greater than 600 (determined by the properties of the photoresistor and series resistance), the animation rate of the first four modes becomes faster ( the frame interval changes from 200ms to 80ms) .

2. Circuit principle description

2.1 General description

Arduino microcontroller simplifies external circuit design and provides numerous possibilities. Therefore, the design on the circuit is not that complicated.

We designed a PCB board for the running water lamp system, integrating an LED driver module and a photosensitive control module. In the touch system, we use the G23 single-channel touch sensor (touch type) based on the TTP223 single-button touch chip .

2.2 Module introduction

2.2.1 LED driver module

The default pin output voltage of the Arduino board is 5V . However, in order to prevent the LED bulbs from being too bright and unable to work properly, we still connected a 220 Ω resistor in series to each LED bulb .

2.2.2 Photosensitive control module

By connecting the photoresistor and the 1K resistor in series, the analog input value is obtained by series voltage division.

2.2.3 Touch module

Using a touch sensor will make the input high and low levels more stable than a touch switch, so there is no need for a pull-up resistor in the external circuit.

This module is a capacitive touch switch module based on touch detection IC (TTP223B) . Under normal conditions, the module outputs low level and the mode is low power consumption mode; when touching the corresponding position with a finger, the module outputs high level and the mode switches to fast mode; when it lasts for 12 seconds. When there is no touch, the mode switches to low power consumption mode again. Modules can be mounted on non-metallic materials such as plastic.

Figure 2.2.4