This project is an LED candle at the dinner table for a couple to savor food with each other. I made this product because I eat five times faster than my wife usually. I never stop using chopsticks, and we don’t talk to each other while eating food. The LED candle induces a couple to eat at the same time. The LED candle is connected to a pair of chopstick rests. Each chopstick rest detects a pair of chopsticks is being used or not with an infrared proximity sensor.
It has three states:
1. If two pairs of chopsticks are on the rest (two people are not eating), the LED candle turns on.
2. If two pairs of chopsticks are not on the rest (two people are eating), the LED candle turns on.
3. If only one pair of chopsticks is on the rest (one person is eating), the LED candle turns off.
*In Korean cuisine context, chopstick rest is a tableware for keeping chopstick tips off the table and to prevent used chopsticks from contaminating or rolling off tables. When people don’t use chopsticks, they put them on the rest during eating food.
*NOTE: The enclosure of this project is made with a 3D printer.
Step 1: Go Get Stuff
You will need:
– (x1) Arduino nano (V3.0 ATmega328P)
– (x1) 9V Battery Case Holder (Case Holder With ON/OFF Toggle Switch)
– (x1) 9V Battery (Duracell Procell Alkaline Batteries)
– (x1) PCB Board (Double Sided Prototype Kit)
– (x3) 220KΩ resistor (1Ω-1M Metal Film Full Range Resistors Assortment Kit)
– (x1) Big RGB LED (EK1721)
– (X2) Infrared proximity sensor (Sharp GP2Y0A21YK)
– (X1) Thick bulky yarn (Red)
– (X2) Wood (size: 50 x 36 x 18 mm)
– (X1) Wood Filler (ELMERS 3-1/4 Oz)
– (X1) Sandpaper (100, 400)
– (X1) Electric wire
– Soldering machine kits
– Knitting kits
– 3D Printer
Step 2: Solder
Use the PCB board as small as possible to put the whole materials in the 3D model.
– RGB LED connects to Red: D7, Green: D8, Blue: D9, and GND (Connect 220 Ω resistor between the digital pin and LED legs).
– Infrared Proximity Sensor A connects to A1, 5V, and GND.
– Infrared Proximity Sensor B connects to A2, 5V, and GND.
– Battery case connects to VIN and GND.
Step 3: Code
Download and use the code.
1. Two Infrared Proximity Sensors detect an object, the LED turns on.
2. Two Infrared Proximity Sensors don’t detect an object, the LED turns on.
3. One Infrared Proximity Sensor detects an object, the LED turns off.
Step 4: Cut and Polish the Wood
Cut the wood (size: 50 x 36 x 18 mm) like a pebble and insert the sensor in the center of the wood. Polish the wood and add wood filler to make it nice. Don’t cover the sensor part.
Step 5: 3D Print
Download and use the file to make a LED candle product.
I designed with Rhinoceros. I used a white filament for the bottom part and a transparent filament for the upper part.
Step 6: Knit the Cord
There are many ways to knit the cord. Please check the tutorial below and find your own way.
2. Without needle
Step 7: Enjoy
Savor the meal with your loved one.