Picture of Arduino-Fart-O-Meter
FART-O-METER color.gif
OH NO! He didn't!

Yes I did!

My project is simple: Farting in a chair and sending the signal wirelessly to a panel that shows the intensity of the fart!

Words of caution: Please do not force yourself to fart, you might shit in your pants if you try to hard!

Thanks to all my friends who helped in this project! (and all my tester!)

Michaël Vachon
Steven Jolley (Fart NINJA)
Manuel Grégoire
Mathieu Desnoyers
Pier-Alexandre Fortin
Louis-Philippe Gagnon
Francis Leconte
Gaétan Mercier
Sébastien Choquette

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Step 1: Component list

Picture of Component list
The project consists of two modules:

The emitter located on the chair and the receiver located somewhere else (e.g. on your desk).

Here is what you need to make a Fart-O-Meter:

1 x large protoboard PCB
1 x ATMEGA168/328 arduino chip with bootloader
1 x LM117 - 3.3V regulator  (Sparkfun sku: COM-00526)
1 x 7805 - 5V regulator 
1 x 1N4148 diode
1 x 16Mhz crystal
5 x 0.1uF decoupling capacitor
1 x 220uf 16V capacitor
1 x Green LED
1 x Bi-Color LED (or two separate green and red LED)
3 x 220Ohm current limiting resistor for LED
1 x 10K resistor for reset of the Arduino
2 x 100K potentiometer - one for gas sensor calibration and the other one for debugging
1 x Audio Jack 3.5mm use to connect the methane sensor
1 x 3.5mm audio jack  (Sparkfun sku: PRT-08032)
1 x 8 x AA battery holder
1 x 9V power clip - It connects to my 8 x AA battery holder
1 x Plastic enclosures
1 x FTDI Basic Breakout - 5V ( Sparkfun sku: DEV-09716)
1 x  MQ-4 - Methane Gas Sensor (Sparkfun sku: SEN-09404)
1 x nRF2401A Transceiver with Chip Antenna (Sparkfun sku: WRL-00152)

1 x Arduino (Solarbotics sku: 28920)
1 x shield (Solarbotics sku:16090)
1 x Transceiver nRF2401A with Chip Antenna (Sparkfun sku: WRL-00152)
1 x Servo motor

Hardware for receiver
1 x large acrylic/plexiglass sheet for mouting everything to it
4 x Silicone Bumpers - so the platform does not slip
4 x HEX 3/8 inch standoffs (Sparkfun sku: COM-00126 ) 
4 x 1/4" Screws 4-40 Thread (Sparkfun sku: PRT-00447
4 x Machine Screw Nut - 4-40  (Sparkfun sku: PRT-10232 )
2 x 1/2" Screws 8-32 Thread for mouting servo
1 x 8 x AA battery holder
1 x 9V power clip - It connects to my 8 x AA battery holder

abraham_219 days ago

Nice One. Thanx Dude

BikeHacker10 months ago


that is sooooooooooooooooooooooo hilarious

Whoa, I received my MQ-4 from China today. Plugged it in, and it had a short. Instead of heating up the sensor element, it turned the printed circuit board red hot. Left some nice burn marks on my fingers. Well, that was every bit as fun as touching the business end of a hot Solder iron..
I also have an MQ-5 in my parts bin, but it's listed as a Liquid Propane gas detector. The MQ-4 was supposed to be for Methane. I hope the seller in China will send me a new MQ-4 that doesn't self destruct.. Maybe by the time it arrives, my burns will be fully healed over ;-P

I did something similar but a bit simpler. Used MQ-9 instead.
This system detects farting and turns on the fan to get a rid of a smell. Once the smell is gone it turns itself off.

robomaniac (author) 2 years ago
I am re-using this protoboard for a new project. I see some design mistake in the power supply.
The input of the 3.3V should be connected directly at the output of the 5V and not 12V.

If you connect them like this schematic, you go from 12V to 3.3V that's 8,7V drop inside the LM1117 voltage regulator. Same for the 7805: 12V to 5V is 7V. Since I use linear regulator, they are not efficient and heat up. The more voltage across them the more they heat up. So by connecting the LM1117 after the 7805 I go from 5V to 3.3V the voltage drop is less and will heat less.

Good luck

liviu_vasut3 years ago
I wonder if you can make the receiver echo the signal back and measure the microseconds it took. Would there be a significant change in time along with varying the distance between the transceivers?

I'm planning on making an autonomous robot and I'm looking for a (local) positioning system. If you have time, please give it a try, I'll drink a bear in your health :). I wouldn't want to buy the parts for nothing.
day-veed4 years ago
LOL!!! I laughed so hard I farted!
octollama4 years ago
lol c'est drole, mes interesant :D
Patented4 years ago
Haha toute qun projet sa ;) vraiment bien expliqué et illustré! Jaime vraiment la clarté des tes images !! Great that you are back on instructables!

robomaniac (author)  Patented4 years ago
Attend de voir le vidéo! :P

j'upload sa demain matin!