Category: Automatic Garden-Irrigation System
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Checking Whether It’s Time to Turn a Valve On or Off
Next, let’s look at the data from the RTC and figure out how we’ll use this to decide whether it’s time to turn something on or off. If you go back to the RTC example ds1307, you’ll see how the time is printed: Conveniently, this is already a number, so comparing with the hours and minutes…
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Setting the On and Off Times
We want to turn the water valves on and off at different times of the day. We’ll need some way to record those values. Because we have three valves, we might use an array, with one entry for each valve. This will also make it easier if we later want to add more water valves. You…
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Coding
Guess what? Writing code (coding) requires planning as well. You need to think a little about what you are trying to do before you start typing away. Similar to the way you tested the new electronics before doing the whole design, you’ll test each piece of code before going on. The less code there is,…
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Testing the Temperature and Humidity Sensor
The DHT11 is a popular Temperature and Humidity Sensor. Like the RTC, it is inexpensive and easy to use with Arduino. According to the data sheet, the DHT11 is connected as shown in Figure 8-13. Note the pullup resistor on the data pin. Because we’re adding a component that needs one, let’s add another 10K ohm resistor…
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Electronic Schematic Diagrams
Most electronic circuits are completely defined by two things: 1) which components are used and 2) how they are to be connected. By capturing only this information as clearly as possible, a schematic diagram is the clearest way to visualise and communicate an electronic circuit. A schematic diagram intentionally does not convey the size, shape,…
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Electronic Schematic Diagrams
Most electronic circuits are completely defined by two things: 1) which components are used and 2) how they are to be connected. By capturing only this information as clearly as possible, a schematic diagram is the clearest way to visualise and communicate an electronic circuit. A schematic diagram intentionally does not convey the size, shape,…
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Testing the Relays
What kind of relays do we need? It depends on how much current the water valves need. Most garden valves seem to use 300 milliamps. This is a small amount of current, and so a small relay is enough. Relays that can be operated at different voltages are available; we’ll use one that uses 5 V…
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Testing the Real Time Clock (RTC)
When I plan to use a device that is new to me, I like to first verify that I understand how it works, before designing the whole system. Because the RTC is new to you, let’s take a look at how it works. The main part of an RTC is the chip itself. The most…
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Planning
Start by thinking about what you want to achieve and what bits and pieces you’ll need. This project will use common gardening electric water valves, available in home improvement stores. While at the store, you will also need one power supply, or transformer, suitable for these water valves. How to use a MOSFET to control a…
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What you had learned about Arduino into a project, the Arduino Networked Lamp. Part of the fun was to combine some of the simple exercises into a practical project. You also learned about the Processing language and how to use it to create a proxy on your computer to do things that would be difficult…