Dēnglóng Carbon Monoxide Sensing Lantern

This was my high school senior year project! Named "Dēng Lóng" (meaning lantern in Mandarin, while dēng means light and lóng means dragon), it would be a mix of the carbon monoxide sensor and the carbon dioxide sensor lamp. I liked the use of the carbon monoxide sensor, as well as the concept of a light that would notify the user when gas levels were high. And I'll design my own casing that takes inspiration from Chinese lanterns. A successful project will have a functional CO sensor as an input, LEDs as an output, a clean casing for electronics, and an I2C LCD screen that lets the user know the safety of their immediate environment.

Here's what you'll need.

You'll also need a 1x6 pin header, a 1x4 pin header, a 1x3 pin header, and a 1x2 pin header, and a double sided PCB.

The electronics are actually a little simple, but it takes time to integrate the different parts of the board into one. One side of the PCB is the LED's, and the other side is the sensor and LCD display. The files can be found at the bottom of this page in the "finalfiles" folder called "doublesided.sch" and "doublesided.brd".

After getting the board files, mill out the designs and solder. Make sure the orientation of the LED's and the ATtiny1614 is correct.

To test the electronics, light a match and hold it under an upside-down glass cup until it extinguishes. Wait until the smoke is caught in the cup, and hold it in front of the sensor. Note that each reading is taken after 2 minutes and 32 seconds, so time the test accordingly.

The code for the project is conceptually simple. It combines the LCD code and LED code into the MQ7 sensor code. Check the file "finalboard.ino" for the code. Program it using an jtag2updi method.

The casing is quite simple. Laser cut the design files in the folder called "finalfiles" > "casing.cdr". Use 1/8"" plywood.

After laser cutting, I painted over the wood in a red acrylic paint and water wash, and painted a dragon on the bottom. You can design the casing however you'd like.

For the 3D printed handle, design any handle you like on fusion. The only design aspect you need to keep the same is the diameter of the circle--make sure it is the same as the diameter of the hole on the top of the case. Then under it, extend the diameter so that the casing top could sit on top of the bottom part of the hook.

On the inside of the casing, there is a rectangle for the electronics. Sit the board under the rectangle; the corners of the board that are empty can be taped to the sides of the rectangle of the casing, so that all the LED's show on the top and the other board modules can be accessed through the bottom. Sit the MQ7 sensor in the small hole, and sit the LCD display in the hole for it. Put the power cord adapter in the small rectangular hole in the side of the casing, and you're good to go!

Here are the files for the project.