I am considering using an Arduino as a controller for a water treatment system and would love to hear your opinions. All it has to do is open/close a water gate (by starting/stopping a motor) at predefined times. It would have to...

  • Be able to connect to a phone using a usb cable. The phone would act as a UI to change settings and water flush times on the Arduino (via a custom app)
  • Log data which would be easily retrievable
  • Ideally, be able to connect to a cell network and send/receive packets. I believe there is a shield for this
  • Consume MINIMAL POWER. All it has to do is flush once every few days, log data, and possibly receive data from shield/usb. It would be running off of a solar panel and battery. In winter it could run out of power.

And thats pretty much it! Can this project be done with an Arduino? I would greatly appreciate any advice and recommendations!

  • Where's the power for the motor coming from? Staying on the cellphone network 24/7 would consume quite a lot of power (think of your phone and how often you have to charge it). If you have enough power to operate a motor powerful enough to open a gate, there should be some over for the Arduino. See my page about power.
    – Nick Gammon
    Commented Jun 22, 2016 at 21:40
  • The power for the motor also comes from the the battery(which comes from the solar panel). I'm getting the feeling that power is going to be the limiting factor here... And thank you for that link I feel it will be very helpful!
    – riverrun
    Commented Jun 22, 2016 at 21:57
  • 1
    If there is enough power to run the motor, there is enough power to run the Arduino. If you have a clock chip on board with a lithium cell battery backup (as clock chip boards normally have) then you could survive a few days of insufficient power. When the sun comes out the Arduino can power up, and then decide if it is time to turn on the motor.
    – Nick Gammon
    Commented Jun 22, 2016 at 21:59
  • Does the arduino do this automatically? Or is this something I will program the avr chip to do?
    – riverrun
    Commented Jun 22, 2016 at 22:27
  • Do what automatically? Everything it does you need to program it to do.
    – Nick Gammon
    Commented Jun 22, 2016 at 23:14

2 Answers 2


Have a look at my Temperature and humidity sensor - battery powered. That works from 3 x AA batteries, and has been going for a few years. I think I replaced the batteries once. It keeps track of the time, and logs data to the disk (SD card).

Temperature logger

I don't have room to describe the whole project here, but the general idea is that the processor sleeps most of the time (consuming around 6 µA). Now this particular project doesn't turn on a motor, but adding a solid-state relay should be all you need to do that.

Be able to connect to a phone using a usb cable. The phone would act as a UI to change settings and water flush times on the Arduino (via a custom app)

I think this will take a lot of power, keeping the phone active. One possible thing to try would be to power up the phone (eg. using another relay) during a certain "window" of time (eg. 6 pm to 7 pm). Then you would know to try to configure the device during that time.

  • I was thinking of having an app that people could download, then when they went to the site plug in their phone to the arduino there. It seems like it could be a way to avoid having a display running, except when somebody connects their phone. It would be very power intensive when connected though
    – riverrun
    Commented Jun 22, 2016 at 22:14
  • If they are going to be onsite anyway, some sort of configuration screen might be easier. Eg. a LCD display to show various options, and a keypad to enter data.
    – Nick Gammon
    Commented Jun 22, 2016 at 22:23

So first of all, if the voltage of your systems is too high, arduino cannot provide that on its own. Arduinos can only provide 5v out with the rail. So you could use a relay shield, an add on board to stack on top of it, or just plain old relays with some soldering. Now, for connectivity, try this thing. http://www.annikken.com/andee/ It is relatively easy to learn, and you can build a decent UI without the need for coding an app. I think you can get them for ~30$. However, I do not know how well the arduino can run with so many shields. For data logging, a few companies make data logging shields, or you can get an external read/write and wire it up. I have a small, probably 3" by 8" solar panel for my arduino and it is quite unreliable even in low power applications. However, if you have a good one, that is cool. Best of luck -Peter

  • I have not had a chance to play with the battery yet, so I don't know what I will need. I will keep the relay shield in mind. The andee shield looks interesting too I'll check it out!
    – riverrun
    Commented Jun 22, 2016 at 21:54

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