Water Valve

[deezone]

Add automated water flow control:

• Water valves on each plant row: https://www.adafruit.com/products/997

From adafruit.com:

We tried this solenoid at various DC voltages and found we could actuate it down at 6VDC (although
it was a little slower to open). Here is the current draw table for various voltages. We suggest a
TIP120 or N-Channel power FET with a 1N4001 kickback diode to drive this from a microcontroller
pin. For a power supply, our 9V 1A or 12V 1A power adapters will do the job.

Voltage Current
6V  160 mA
7V  190 mA
8V  220 mA
9V  240 mA
10V 270 mA
11V 300 mA
12V 320 mA

Controlling a Solenoid Valve from an Arduino

• http://www.martyncurrey.com/controlling-a-solenoid-valve-from-an-arduino/
  Parts

• TIP120 allows a small dc voltage (from the Arduino) to switch a larger dc voltage (12V to the solenoid).

• The diode (a 1N4007 in this case) connected to the solenoid allows current to flow only in one direction. > When the current is turned off the solenoid tries to continue the current. This can fry the Arduino.

  The diode feeds this current back in to the solenoid until it is dissipated.

• To open the solenoid you just need to set the Arduino pin connected to the TIP120 HIGH. It is the same as turning on a LED which you can see in the Blink sketch.

Related projects:

• 12V to 5V / 6V : http://www.martyncurrey.com/12v-to-5v-6v/

  I have never been happy that my first version of the drop controller had 2 different power supplies;
  a 12 volt supply for the solenoid valves and a second 5 volt supply for the Arduino

• Solenoid breakout board V2
  http://www.martyncurrey.com/solenoid-breakout-board-v2/
• Secret Knock Activated Drawer Lock
  • Code for controlling solenoid
    https://learn.adafruit.com/secret-knock-activated-drawer-lock/code
  • Wiring for solenoid
    https://learn.adafruit.com/secret-knock-activated-drawer-lock/wiring
    

Other Notes:

• Mosture / water sensors on each plant row
• Water valve control at the end of each plant row