Introduction: ARDUINO Fume Extractor With Touch Sensitive Buttons

Hi, thanks for checking out my first instructable.

After after a year with the mk1 , I realised its time to upgrade. The main things i concentrated on the upgrade was LIGHTING and SIZE. On the mk1, i had a single throw switch which worked fine, but keeping up with modern tech.. i decided to add touch buttons instead.

Sorry No real plans or schematic exist for this build, it is all in my head. But i have every bit of faith that this is a walk in a park for you.

Step 1: Step 1: BOM (parts)

- An encloser ( i used a box that has 12x cat food pouches)

- 3/4 pc fans, ( i salvaged a twin fan from my xbox 360)

- Arduino nano

- NANO dip ( so you dnt solder your adruino to pcb like a did, make it much easier to change

- 3x tip122 transistor

- 360 degree led 12v W5W

- 9g servo

- 5inch piece of wire ( 16 gauge enamel copper will do)

- 2inch wire ( 20-22 " ")

- 12 5mm leds ( you choose color)

- 12x 180ohm resistors

- 1 diode

- 8 pairs of female and male connectors

- perfboard 3inchx4inch

-12v 3amp+ dc supply adapter (i didnt have 1 so used an old laptop power brick with a buck stepdown)

- 5v regulator

- 2x 10uf electrolytic capacitors

- air filter

- soldering iron

- foil

- 2x 6.6Mohm

- heat shrink tubing

- hot glue gun

- superglue

- duct tape

- 3x Roughly A4 pieces of reasonably strong cardbord

If you decide to a backlit sign

- cd case

- spray paint (any colour)

- electric tape

- circle cutter (relevant to my design)

- white paper

- coloured light filter (red in my case)

Step 2: Step 2: the Shell

Before you start putting it all together, make sure all the components will fit in your enclosure. Make sure your pcb and its components fit. If they don't, change the box or find a way to enlarge it.

Pull the box apart at the joints, my box is joined together with hot glue so i just pulled those tabs.

Now that your box is flat..

Measure the diameter of the fan Cut holes where you want the intake fans and exhaust fans with the circle cutter. after this, you could spray paint the exterior now.

Step 3: Step 3:The Circuitry

This is one of the easiest circuits out there, but was a challenge for me. I'm not going to give exact details of the circuit for two reasons.

1. if you're no stranger to electronics then this is easy for you ( you prob could make it better)

2. If you are learning then this is brilliant for you as it will give you a chance to develop.

If you understand transistors, resistors and have basic arduino knowledge.. this should be a walk in a park

Using the CapacitiveSensor library. Jump the 6.6Mohm resistor across pin 2 of arduino and pin 4. Attach a long wire to pin 2, this serves as the sense pin. this will be power button (fans, and all leds)

for light, jump the 6.6Mohm resistor across pin 2 of arduino and pin 6 and like last time attach a long wire to pin 6 and this will be the light sense. Keep in mind you can change the pin designation in the code. so the power could be light and vice versa.

the wires as they are will work as capsense, but we need to have pads to touch. for this we use a tiny bit of foil wrapped around exposed wire. this foil will be attached to your control panel.

test this circuit on a bread board before soldering.


I started with the NANO followed by the 5v regulator and capacitors. after soldering in the transistors added resistors for led array

Most of the time for me went in the soldering and debugging 20%, writing code 45%, Debugging code 35%

Step 4: Step 4: Control Panel and Backlit Sign

The control panel and backlit sign are on the same piece of material.#

Using a clear piece of a CD case and electrical tape, stick strips of the tape horizontal.. living no gaps and repeat process with vertical strips, living no gaps.

Draw your design on a paper or if you cannot draw you can always print one.REMEMBER to draw a mirrored image. using extra tape, secure your design on top on the taped cd case and cut out sections you do not require. Now carefully remove your template design and stick it where you want it to go. REMEMBER. stick it under the panel (the side you won't touch) Leaving enough room for buttons. Before spraying, also have in mind the shape of your buttons and cover those bits. unless you want your buttons the same as the panel ( i went for clear so i can attach status led's)

Now you can paint.

using the back end of a 5mm drill bit, heat it up and make hole this is where your foil wrapped in wire will go into.


using a small perfboard, i soldered a few led's ( the number changes with the brightness you want to archive or how bright the led's are to begin with.

Now grab your painted panel, make sure its dry. You should have (if you chose my design) the A see through as well as the circle around it. on the underside where you have sprayed. stick a white piece of paper followed by the light filter of choice.

Step 5: Step 5: Light and Mechanism

The light for when i'm soldering and its deployment method is unique. this is the first on the internet to my knowledge, but i digress.

first,extend the cathode and anode, make a tube to hold the light and secure with hot glue.

second. make a tube slightly bigger than the light holder, this will act as a guide an test it.

secure the bigger tube to a piece of card (same size as the side of the enclosure).

cut the 16 gauge wire to size (where ever you decide to put the servo). bend a 90 degree angle 3mm from each end in the same direction.

using a 2 inch piece of thinner wire (20-22 gauge) make a small ring (small enough for 16 gauge) and twist the remaing wire together into a tail. and hot glue just inside the smaller tube behind the led.

slip one end of the 90 degree bends in this and the other to the servo horn( cut off the arms and leave one, cut that one left short living two holes, the second hole will be where the other end of the 90 degree bend will go into. if there is a fitting issue, heat the end and slip it in, the plastic will melt and blah blah blah)

line up an secure with hot glue. connect your servo to your arduino and test, keep note of the two positions you need. mine, when ON 20, OFF 165.

Step 6: Step 6: Software and Testing

this code is basic. you will have to develop it further yourself (learning curve and all that). If you do have any difficulties i will offer help.

#include <capsense.h>

Capsense cs_4_2 = CapSense(4,2);

const int ledPin1 = 13;

void setup()


cs_4_2.set_CS_AutocaL_Millis(0xFFFFFFFF); // turn off autocalibrate on channel 1 - just as an example Serial.begin(9600);


void loop()


static boolean lastSensorHit = false;

static boolean LEDvalue = LOW;

bool sensorHit = cs_4_2.capSense(30) > 1100;

if (sensorHit && !lastSensorHit) // Now true, was false { LEDvalue = !LEDvalue; // Toggle the LED digitalWrite(ledPin1, LEDvalue);


lastSensorHit = sensorHit;



Step 7: Putting It Together

Put everything together securing the fans with hot glue, making sure the are blowing the same direction.

I had drawn a skull and cross bones with 2 red leds for eyes, but i find it pointless now that the project is complete also i think its messing up air flow. Its stuck to the base with gorila tape.

Once again, im sorry to not give Full details. The way i see it is, if you're building one of these you like doing this and want to learn more. And having an full manual doesn't do you any good in the long run.

I will offer help if stuck.