Hi all,
I would like to ask you if somebody has experience with some small 12 V ultrasonic humidifier controled by Arduino. My plan is to use standard Arduino Mega with Ramps 1.4 which is intended for RepRap 3D printers but could also perfectly work for my project. I need to control humidity of small space (about 1/2 square meter). I found interesting ultrasonic humidifier plates but there are mostly no information about voltage. Because I plan to use it with the boards mentioned above I was thinking to use some of the 12 V humidifiers which would be connected to the outputs of the Ramps 1.4 which are designed for 12 V outputs.
Anyway, any other solutions are also in place if you have any previous experiences. I was just thinking of non any aditional wiring and boards making if the Arduino Mega with Ramps 1.4 would be used. That was the preferred way.
It seems you forgot to post a link to that humidifier.
In general: you can switch the power to a 12V DC powered device on and off easily using a signal from an Arduino and a MOSFET. What the device internally does is irrelevant.
Which MOSFET depends on the amount of current used, and whether you have 3.3V or 5V signals.
Ok, I understand. I just wanted to use ready to use solution in form of Arduino Mega and Rapms 1.4 as I wanted to avoid aditional boards making stuff and also wanted to use spare parts which I have at home.
By the way I am also thinking about 5V power supply to humidifier and other stuff connected via standard USB ports. Do you know about any Arduino compatible board with couple of USB ports where power supply to each of them could be turned ON/OFF by Arduino?
No such shield. You normally have to build your own circuit to switch whatever you want to switch.
Anyway you'll first have to figure out whether that mister is useful for you, or find another one that is. When you know what you want to switch it's time to start worrying about how to switch it.
I don't know much about driving those things, but they do require quite a bit of power.
Just FYI - "Mist" is water droplets and it's NOT humidity. Humidity is H2O in the gaseous state... It's not wet. When the droplets evaporate, it contributes to humidity. But, a glass of water or a water-soaked sponge or rag will also evaporate and contribute to humidity and if there is enough liquid in the container you'll eventually reach 100% humidity.
If you have high relative humidity and you reduce temperature, you can create fog or rain because the cooler air can't "hold" as much gaseous water and water gets "squeezed" out as you "try" to go over 100% relative humidity.
I found following shield: yepkit It is not direct board for Arduino but I think could be used.
Thanks for your posts. I found some 5V humidifiers which I will most probably give a try: humidifier
Anyway I will also try to search for some more suitable USB power switching device which could be connected to Arduino or as you said will try to find some circuit which could be used for it as I am not able to designe my own board for such use.
That yepkit thing is not going to work for you. It's a USB hub thing, and Arduino can not do much if anything with USB communication beyond programming and the Serial console. Just forget it, you're looking the wrong way.
That humidifier looks like it will work with an Arduino. You'll have to cut off the USB plug it no doubt comes with, and connect it directly to your project.
boylucky:
I am not able to designe my own board for such use.
Then it's time for you to learn how to do this, as building a power driver is a very basic thing to do when working with Arduinos, and you will see it come back time and again. Most projects will require some form of external circuits.
These drivers are pretty simple - just a transistor (BJT or, preferably, MOSFET type) as switch and a few resistors. Build it on solderless breadboard first, then solder on a piece of protoboard for more permanent use. This humidifier is rated 2W, so 400 mA at 5V. Way too much for an Arduino to supply, but small enough to not require anything special of the driver circuit.
You seem to have forgotten part of your original posting.
You said you want to "control" humidity. Nowhere have you mentioned any way to measure the humidity and since temperature is directly involved, you don't seem to be concerned about the temperature.
Ok, I understand. I just wanted to use ready to use solution in form of Arduino Mega and Rapms 1.4 as I wanted to avoid aditional boards making stuff and also wanted to use spare parts which I have at home.
It's funny! I thought that I was the only one with this idea. It's good that I found this thread, I hope thanks to you I will not make mistakes in such a project. You have to come up with something else to complicate the project.
a simple perf board for $1
a MOSFET for $1
some resistors, a diode (1N4007?) pennies
solder and iron (cheap stuff for under $10)
these are the tools of a Maker
if you are working with a RepRap, I would assume that you want to be able to alter some electronical things now and again even is just to add an LED.
as for the 'from the spare parts which I have at home' I think that 80% of us have bought a new sensor, switch, board, shield, etc knowing full well there is one in one of the parts boxes, but that it it is just easier to order a new one than to dig through the parts bins. The other 20% get the new one, well, 5 for $1... then put the other 4 into 'storage only to find there are 4 there from the last buy.
[quote author=dave-in-nj link=msg=4272503 date=1565606976 put the other 4 into 'storage only to find there are 4 there from the last buy.[/quote]
LOL sounds very familiar.
But in my case it usually means I forgot I still have some as if I remember I'll start searching instead of waiting a few days for the sensors to arrive.