URGENT: School project - arduino uno humidifier pls help 😭

[biim]

@xfpd

You must. In what way are they not reliable? This is how real projects go... your teacher should know about this.

What will you be sensing/testing with the MQ135? It seems unnecessary unless you are instructed to detect gases. Humidity will be detected/sensed by the DHT.

It looks like you have the LCD plugged into DIO#4 and DIO#5 (+pwr, -gnd).
The LCD should be plugged into A4 and A5.

UNO R3      Peripheral module
==========  =================
DIO PIN  2  - MQ135 digital output ** (your picture is missing this connection)
DIO PIN  3  - DHT output
DIO PIN  9  - Buzzer output
AIN PIN A0  - MQ135 analog output
AIN PIN A4  - LCD DATA
AIN PIN A5  - LCD CLOCK
POWER RAIL  - Arduino 5v, MQ135, DHT, LCD
GROUND RAIL - Arduino GND, MQ135, DHT, LCD, BUZZER

Your power supply must be 5vdc in this case. You should wire everything together and use the following stand-alone module test sketches. When they all work, you should combine the sketches.

Hi Thanks for replying and sorry for late reply

The MQ135 is included to demonstrate air-quality monitoring which aligns to our sdg focus..

[biim]

@kmin

I have no problem helping with that, but you need to verify how your mist module behaves.
It likely does not start mist by applying power and you need to press button. But if soldering is not an option here, you need to try this: Test your module first normally with water (no arduino, just usb). Then try if you hold the button continuously pressed and then power the module, does it start misting after 1s or so ?
If yes, you can glue the button down or use food bag clamp for example. Then you can switch the power with relay.

Our robot monitors humidity and air quality using the DHT11 and MQ135. When the humidity drops below the set threshold the Arduino sends a signal to a relay, which is meant to switch power to the ultrasonic mist module to increase humidity. When humidity goes back to a safe level, the relay turns the mist module OFF. The LCD displays the readings, and the buzzer activates when air quality is poor.

[JCA34F]

Tell us the brand name and exact model number of your mister so we can determine if it will even work with Arduino.

[kmin]

@biim

which is meant to switch power to the ultrasonic mist module

That doesn't help if the module doesn't start mist when powered on.
Read my post above carefully.

[biim]

USB Mini Humidifier DIY Kits Mist Maker and Driver Circuit Board Fogger Atomization Film Atomizer

[Paul_KD7HB]

@biim

USB Mini Humidifier DIY Kits Mist Maker and Driver Circuit Board Fogger Atomization Film Atomizer

Does it work? Seems to be triggered by the push button and will automatically turn off after some unknown time. Since it runs off your USB connection, please confirm it’s operation and if this will work in your project.

[LarryD]

• Can you measure the current the module draws when it is running ?

[biim]

I dont know yet but im about to try . This is what my teacher did so that we dont have to solder

[xfpd]

The atomizer does not have a signal wire.
The LCD SDA/SCL arenot connected to A4/A5.

[GolamMostafa]

@biim

I dont know yet but im about to try .

Try one component at a time. If you connect everything together at once, there is an almost 100% chance that nothing will work.

@xfpd

The LCD SDA/SCL arenot connected to A4/A5.

@biim
Check that SDA/SCL lines of LCD has reached to A4/A5 pins of UNO.

[biim]

Yes im trying to test one component at a time but like I still dont know how to wire the relay and mist module

[GolamMostafa]

Test the LCD to show the message Arduino on the topline. Afterwards, come back for the help to connect realy and mist module.

What is a Mist Module? Show its picture and type number.
What is the function of the relay. Show a picture of your relay.

[J-M-L]

@Paul_KD7HB

Seems to be triggered by the push button and will automatically turn off after some unknown time

So it could just be a matter of removing the button and driving it through an optocoupler or if there is no current flowing through that straight from Arduino pins.

It would be interesting to know of just power cycling the unit starts it.

The auto shutdown is 4h from what I read .

—-

@GolamMostafa

What is a Mist Module? Show its picture and type number.

You can find this module all over the internet - Google « usb mini humidifier diy kits mist maker »

[tigger]

@biim

You've been thrown in at the deep end by the looks of it.

These sort of exercises are more to do with getting you to think things through before pitching in trying to get everything to work at once.

In the world of industry and processes, you can be faced with these problems all the time and sometimes, the buck stops at you.

If you are working in a group, divide the tasks up.

Even getting a relay to work is satisfying. Learn how a small current can control larger ones, then how a transistor can control the relay. Then onto how writing some code for the Arduino can control a digital pin to control the transistor.

Once you master that bit (no pun), you can control anything.
You have all the resources you need courtesy of the WWW.
As an aside, think how difficult it used to be. Just books, manuals and catalogues to trawl through. Persevere and you'll get there.

[kmin]

@biim

This is what my teacher did so that we dont have to solder

So maybe he/she made a solder bridge across the button contacts as well on the back-side of the module...

[biim]

@Paul_KD7HB

Seems to be triggered by the push button

omg I didnt noticed there was a button like on the thing Ill try to test it later

[kmin]

@biim

omg I didnt noticed there was a button like on the thing

Also you didn't read posts here...

@kmin

I have no problem helping with that, but you need to verify how your mist module behaves.
It likely does not start mist by applying power and you need to press button. But if soldering is not an option here, you need to try this: Test your module first normally with water (no arduino, just usb). Then try if you hold the button continuously pressed and then power the module, does it start misting after 1s or so ?
If yes, you can glue the button down or use food bag clamp for example. Then you can switch the power with relay.

But in case your teacher solder bridged the button as well for you, then you can try like this:

[xfpd]

Judging by the power/ground jumpers, I think those pads on the atomizer are for external power, but the button still needs to be bridged.

I think the relay should bridge the button Normally Open contacts.

[kmin]

If the teacher soldered the wires for them so students don't need to solder, I would expect that he took care of the button as well...

[GolamMostafa]

What is the purpose of USB-C connector of the Mist Module -- is it to be connected with PC to get 5V?

How much voltage is required for the Mist Module to work -- is it 12V? If yes, where they should be connected -- is it across + and - terminals of the board? The 12V must be supplied by the relay contact -- is not it?