Tutorial: Adding LED Grow Lights to SmartGarden3
This is a tutorial showing how to add a controlled LED Grow Lights to SmartGarden3.
What is SmartGarden3?
The SmartGarden3 system (currently on Kickstarter) allows you to build your own remote monitoring and management system for your indoor or outdoor garden. Do you want to share your garden and the weather world wide? You can learn the Raspberry Pi and how to connect to the real world through this easy to build no-soldering kit. You can measure soil moisture and then use that as feedback to provide your plant or garden just the right about of water.
LED Grow Lights
There are hundreds of different brands and types of LED Grow Lights available. We have chosen one brand of LED Grow lights for an example. We chose the Litever 45W 4 strip grow light because it was inexpensive, had all the mounting hardware and was easy to modify.
First we will show how to modify the the Litever Grow Light for use with the SmartGarden3. We will be using one of the relays on SmartGarden3 to control this light. Specifically, Relay Number 8 (Valve 8 in the software).
Cautions
- Turn all power off and unplug the SmartGarden3 Extender and the Grow Lights (or any other device you are using) before starting this project
- Keep water away for uncovered electrical contacts at all times
- Cover all soldered or exposed wires with heat shrink tubing or electrical tape
- Be careful. Electricity is dangerous!
What is a Relay?
A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact formats, such as make contacts, break contacts, or combinations thereof.
You use a relay to switch higher voltages and currents than can be handled by normal Raspberry Pi type of electronics.
The relays used in SmartGarden3 have three inputs per relay. These are:
- NO – Normally OPEN – Device OFF
- COM – Common
- NC – Normally CLOSED – Device ON
If you want the device to normally off (off on startup and when it isn’t being powered), then you would connect one end of your wire into NO (Normally Open) and then other end into the COM (Common). If you want your device normally on, you would connection NC (Normally Closed) with the other end of the wire in COM (Common).
The relays on SmartGarden3 can switch either 120/240VAC or up to 30VDC at up to 10A which gives you a HUGE amount of flexibility.
The Relays on the SmartGarden3
Note: In this and other SmartGarden3 manuals, for convenience we call the switched USB ports and Relay outputs “Valves”. “Valves” refer to any switched device such as valves, pumps, lights, fans, windows, motors etc. They can all be controlled by SmartGarden3.
Below are annotated pictures showing the valve number of each of the relays and usb ports on the back of the SmartGarden3 in the 3D Printed enclosure
Installing and Connecting your LED Grow Lights
The way relays work is that they act like an on/off switch. You cut the wire you want to connect or disconnect and run it through the relay (either through NO and COMMON – Normally Off or NC and COMMON – Normally Closed – On – and COMMON).
Step 1) Collect your Materials
- Soldering Iron
- Solder
- Wire Clippers
- Wire Strippers
- Heat Shrink Tubing
- Electrical Tape
Step 2) Locate the Power Supply from the 45W Everlite
Step 3) Cut the wire about 1 foot (300mm) from the end of the circular plug
Step 4) Strip off the outer insulation and leave about 1.5 inches of wire showing. Strip the ends of the wires about 1/4 inch.
Step 5) Tin (put solder on the ends) of all four of the exposed wires.
Step 6) Slide a 1 inch pieces of small Heat Shrink Tubing over one of the black wires.
Step 7) Solder the two black wires together.
Step 8) Slide the heat shrink tubing over the soldered joint and using a heat gun or a Bic lighter, shrink the tube onto the black wires.
Step 9) Wrap the joint with your electrical tape. You may want to wrap the other wires for mechanical stability, just letting the two red tinned wires sticking out.
Step 10) Unplug any power to the SmartGarden3 extender unit. MAKE SURE YOU DO THIS!
Step 11) Place one red wire (either one will work) in the NO (Normally Open) of Valve 8 (Valves 4-8 will work, but make sure your programming below reflects the one you chose) and screw it down. Make sure it is tight.
Step 12) Place the other red wire in the COMMON of Valve 8 (Valves 4-8 will work, but make sure your programming below reflects the one you chose) and screw it down. Make sure it is tight.
Now your are done!
Plug in the SmartGarden3 Extender unit and connect the power supply to the light using the cables provided.
Now to test the Grow Light with the SmartGarden3.
Test Your Unit with Manual Control
Open up your dash_app on a browser (after starting the server on the Raspberry Pi as shown in the manual) and then click “Valve 8” on your Extender (Extender Test2 in this case). It will turn the lights on for 10 seconds and then they will go off again. Success!
Programming SmartGarden3 for 12 hour on Grow Lights
It is most likely that you will want your grow lights on for 12 or so hours a day, but we will just run a test that will turn on the lights for 600 seconds every 15 minutes for the test.
Start up your SG3Configure program and go to the browser window as shown in the “SmartGarden3 Assembly and Test Manual”, go to the SG3 Configure Tab, select your Wireless Extender that you have wired the lights into and then select Valve 8 from the dropdown Valve Select Menu. Fill out the rest of the fields as shown and then click “Save Valve”. Finally, click “Save and Exit” and start your SmartGarden3 as shown in the “SmartGarden3 Assembly and Test Manual”. After you have started the SmartGarden3 software, you will see the lights turn on the quarter hour.
