Automatic watering - need recommendations for books to read.

Hi there :slight_smile:

Thanks for a great forum.

I am almost through "Getting started with arduino". But i dont really feel it gave me the knowledge i needed to build my system.

I pretty much have designed the system (water container, 12V sprinklerpump from a car sprinkler, hoses, and done, a cellphone charger/other power supply). I believe i have learned how the code shall be. For starters im trying with a predifined timer, and later i will experiment with humidity and light sensors.

But the problem is, i cant really see how im supposed to built it. I would like to make a permanent version. But im confused about how to. How do i control a 12V when the arduino uno, which i have, only says 9V.

So i'm thinking i need to read a bigger book. Maybe one which goes a bit further into the electronics.

Can anyone here recommend which books i need to built my wateringmachine?

There is nothing wrong with "Getting started with arduino", actually, its very well written, so i got the basics fast, but i "need more", if you know what i mean. :slight_smile:

Cheers and thumbs up for arduino! :smiley:

I like this free book - - which explains apps quite good.

For the rest, just get started with a high level outliine of your application and if questions arise come to the forum!

There are many steps to learn, and just take them one by one, and combine them to see how it works. Taking a bit extra time for understanding will pay back later .

E.g. the 12V you can solve with a separate powersupply (and you will learn that you need to connect GND's)

Can you post a list of what the watersystem should do? in detail? preferably in an unambiguious way. So a sentence like

the wateringsystem gives plants water when the ground is dry. contains a lot of info but details are missing. (how many plants, how much water, how dry)

Thanks, ill read that one before posting any more questions. I don't want to ask too much :wink:


The device will water the plant area in two sections of the day. The plant area (wheat grass, very healthy - look it up!) will be watered one time pr. day by a direct injection to the soil. And 2-4 times pr. night via sprinklers that sprays out over the plants.

The device will be controlled by a clock, so that once a day (e.g. at noon), sprinkler 1, the direct injection, delivers x amount of water, and at night sprinkler 2 will spray the plants.

The system will consist of (as i have planned it right now, with the knowledge i have):

  1. Arduino UNO to monitor the time of the clock, and give orders to the 12V pump.
  2. 12V sprinkler pump from a car sprinkler. A newer model with 2 outputs (for sprinkler 1 and 2). and a water container which the pump can get it's water from.
  3. A knot for controlling the amount of water delivered (this is still a thing im trying to figure out.).

The plan is to design the system for my self, and also to develop a schematic so that people like my self can get a very easy built watering system at home, without spending a lot of money. The knot is so that the system can be adjusted to different types of plants. Chili needs different amounts of water according to the time of the year (heat, sunlight and so on), as do other plants need some adjusting.

My opinion is that you can tweak the outcome of your plants, if you water them perfectly. Thats also why adjustable amounts of water gives the user an opportunity to tweak their watering routines.

I'll be back, when new questions arise :slight_smile:

Feel free to comment :slight_smile:

Hi. I like your project.

  1. Control the amount of water just by timing how long the pump is on.
    Start with 10 seconds or something appropriate ( Pump On delay (10 * 1000); Pump Off)
  2. The pump will draw more current then the 30 ma of an Arduino pin. More like 250 ma or more.
    Simply use a power Darlington. Look at the ULN2068B chip; it has 4 of them.
    Good for up to 1.5a - more than enough to control up to 4 pumps.
    ( )

The main thing is to use a common ground for your Arduino and external heavy duty 12v supply.
The 12v+ goes to the pump+ and the K pin; The pump- goes to the C pin.
The E pin goes to ground. The B pin goes to your Arduino dig out pin.
Should work like a charm. You can and should breadboard and play with the ULN2068B chip and pump control before anything.
Just connect the B pin to 5v or ground instead of using the dig out pin.
(note other power darlingtons may not have the diode or input resistor, which you would then need to add externally)