How to Make a Fart Tracker

Hi, my old friend in my childhood, who have tried find out the fart by smelling, how are you today?

It happened in my primary school. I remember that the class would always add transfer students in every year. In the end, a small classroom was crowded with more than 50 students. And only two narrow aisles were left for one-way passing. One day, when I was too tired to stay awake during the class, loudly noise spread…with a strong fart smell.

Hold the breath and listened carefully, my 2 classmates were arguing that the counterpart farted.

Our classroom is too crowded, this kind of things happened occasionally. You blamed me, I blamed you, arguing and ended with no result. Well, that time, something different happened. There was a famous naughty boy set behind of those 2 arguing students. He looked at them for a while, thinking, then clenched. It seemed like that he was making a big decision. Suddenly, he stood up and worked straight to them. Without hesitation, he bent and putted the nose to their button, oh my! My hero!

I have just got a DFRobot CCS811 Air Quality Sensor that can measure volatile gas and CO2 concentrations. The test result shows its accuracy and sensitivity. And I want to make a fart tracker to free the human nose from fart monitoring.

Since the fart is not appear, I have to use the alcohol lamp to do the demonstration.

This CCS811 air quality sensor, which takes a very short time from start-up to normal operation. It enters the operational state quickly and has many advantages like low power consumption and threshold interrupt alerts. Its fast response and high sensitivity surprised me. Put it on the table and I was typing, the serial monitor can clearly reflect my current exhaled CO2 concentration. Amazing! It my first time to see the exhaled gas could pile up like a ball on the desktop. From its wiki introduction I know that the CCS811 value would have a large fluctuation with elements such as breathing, gas, farting, alcohol, etc.

Making Progress

1. Principle

Taking advantage of the ability to volatile harmful gases in CCS811air quality sensor, selecting Nano as the main control to receive values of harmful gas concentration from CCS811 sensor and map data to the LED brightness via the function map (). The closer the distance from the sensor to the releaser, the brighter the LED.

2. Materials in Need

Gravity: CCS811 Air Quality Sensorx1

DFRduino Nano V3.1 (Arduino Nano Compatible) x1

Gravity:Digital Piranha LED Module – Redx1

Lithium Battery Chargerx1

3.7V Lithium Battery x1

Dial Switch x1

3. Modeling and 3D Printing

4. Uploading the code

5. Hardware Connection

(1) Connect the battery to the charger board

(2) Welding the wires to dial switch and put it to the model

(3) Welding the red wire of the dial switch to pad “+” of the charger board and welding one black wire to pad “-”.

(4) According to the hardware connection diagram to weld and connect Nano, LED and CCS811.

(5) Take gravity ports of LED and CCS811 out from the inner part of the model.

(6) Plug the black wire and the red wire od the charger board to Nano, Black to GND and Red to Vin.

(7) Stick the charger board to inner part of the module with hot-melt, fixing and exposing the micro-USB charging port.

(8) Fix LED and CCS811 air quality sensor to the module with hot-melt.

(9) Organize all parts and wires and prepare to plug them inside the handle:

(10) Bond the two parts of the model with a little hot melt:

Accomplished!

Charging