Need help selecting a board

I’m new to arduino and I need help selecting a board.

I would use it for a controller on my saltwater aquarium

Turning off and on power to equipment

Testing ph, nitrate, nitrite, temp, calcium, salinity, and maybe more

Controlling leds



And probably more

I realize that one board will not get me where I’m wanting to go but I just need a good starting point on which board or boards to get.

Any guidance would be very much appreciated.

Count up all the inputs and outputs required, and buy an Arduino with at least that many.

Hi, Joshd123.
Welcome to the forum.

Please read the first post in any forum entitled how to use this forum.,148850.0.html.

Can you please tell us your electronics, programming, Arduino, hardware experience?

As @jremington has suggested, list your I/O and if possible what type of I/O signals you will need to read from and write too.

Sensors for testing the range of water characteristics can be expensive and have varied signal output methods.

Have you googled arduino aquarium controller monitor

Tom.... :slight_smile:

I studied Ohm’s Law, kirchoff's law, fundamentals of electric motors, schematics 1, 2, and 3, 12 volt, 110 volt, 220, 480 and 600 volt in the army but that was 20 years ago.

Maybe a little better than basic understanding of a fluke multimeter

Various types of power generation.

As far as programming I used MS-DOS.

New to Arduino

I built a few computers.

I am an accomplished DIYer with hundreds of completed projects under my belt including building high powered Led grow light systems for coral growth, diy automatic rollermat Theiling filters, installed some solar arrays, designed and built one of the worlds loudest car audio systems. I have a good understanding of the basics but the Arduino or systems of this type are not something I have worked with much.

I want to use the 16 relay channel relay. Not sure if that would need one I/O or 16 from the board.

at least 8 extra I/O

I am thinking of using color sensors to decipher the color of existing test kits for color blind people but open suggestions of Turn key probes to add to Arduion

I have googled but am worried that the boards they used are outdated. I was researching all of Arduion’s boards but quickly got overwhelmed. I am hoping someone can just tell me which board would be best and I’ll go from there.

I want to use the 16 relay channel relay. Not sure if that would need one I/O or 16 from the board.

You might or might not need opto isolation (safety, interference).
If you do, then don't use a 16-channel relay board.
They have optos, but no way to use them (design fault).

I don’t understand what your saying.

Opto couplers are used to create an exta safety layer between the Arduino and mains power.
2-8 channel boards have those opto couplers, and you can choose to use them or not (with a jumper).

16-channel boards also have them, but the evil designer didn't add the selector/jumper.
That makes the optos on a 16-channel board useless/ornamental.

You have to decide if you need that extra safety layer.

Get Arduino Uno - cheap and easy, hard to kill and with enough pins for lot of fun. When you get some experience you will know what board (or standalone MCU?) to use. Simply counting I/Os is a poor lead IMHO. There is plenty of other important questions - do you want 5V or 3V3 system? How much memory and processing speed is needed? Maybe you will want more than one controller. I.e. one for doing the life supporting part that should be as simple as possible to prevent some catastrophic failure and other for the fancy stuff as WiFi connectivity, operating displays etc.

I want to use the 16 relay channel relay. Not sure if that would need one I/O or 16 from the board.

at least 8 extra I/O

In the lack of further evidence, that has probably accounted for 24 pins, then there is the other stuff you will think of next week. The answer is a Mega, there is no point in sailing so close to the wind with anything else. With all that i/o, you are likely to need a Mega for its memory, without bothering to count the pins.

I assumed each boards where expensive. I had no idea they are so cheap. I will probably buy a nice starter kit to play around with and learn.

I had also kicked around the idea of paying someone to build me something turn key. So if anyone is interested shoot me a price on a turnkey project.
Thank you for all your help and advice.

Since you have a clear project in mind, A starter kit isn't such a great idea. It is not likely to have the stuff you need but it is certain to have a lot of stuff you don't need. Just get a Mega, and add the sensors, one at a time.