Update: Grow controller rebuilt to last


[The Cheap Vegetable Gardener] assembled his first grow controller about three and a half years ago. He’s been very happy with it and knows that he’ll be using it for years, maybe even decades to come. He just finished overhauling the grow controller design to help make sure he doesn’t burn down his garage one day. You have to admit, without knowing anything about the project this rendition does look safer than his original offering.

Pictured above is the weather-proof enclosure he used to house four mains-rated solid state relays. This box is isolated from the control hardware, providing heavy-duty utility plugs to interface with the heater, lights, fan, and water pump.  He mounted the Arduino board which controls the relays to the outside of the box, using the Ethernet wire to switch the SSRs. It uses a manufactured shield he designed which will help ease the pain of fixing the system if parts ever go bad.

Later on in the build he shows the grow light and heaters used in his operation. The heaters simply screw into light sockets; something we’ve never come across before.


  1. dALE says:

    inb4 “not vegetables”

    yes, actual vegetables.

  2. David says:

    inb4 “bowl of pot bottom right”

  3. Sherry Verrall says:

    Wow, looks like a great job of originality to make plants grow more effectively on their own. Good job, Cheap Vegetable Gardener!

  4. rduke says:
  5. Do you know who I am? I'm the CEO of a multi-million dollar hole in the ground. says:

    What’s the point of dealing with mains/SSRs yourself as opposed to buying UL-tested controllable mains switches? I know that off-the-shelf isn’t much of a hack, but the real novel parts seems to be the sensors and control software, not the mains-exposed hardware. Unless you are qualified to be mucking with mains directly, why risk it for a hobby project?

    • Rob says:

      Looks like he’s got the household-voltage stuff under control. Wiring up a switch (or relay) really isn’t that big of a deal for anyone who knows how to turn off a breaker. And it’s all in one nice, neat box this way.

      Certainly less dangerous than the concept of indoor gardening in general, which can totally wreck your front door, just for starters . . . cf http://www.kansascity.com/2013/05/03/4217089/records-leawood-drug-raid-based.html

    • Also worth noting that many of the commercial versions use mechanical relays for cost savings which should fail much sooner than SSR. My secondary reason was cost given I can buy a SSR for $5-10 versus $20-30+ for a UL-tested component.

      Though I do agree if you are not comfortable dealing with high voltage I would definitely recommend going with a commercial solution like the CatTail (if they still make these)

      • Mike says:

        I haven’t seen the specs for this yet, and maybe I shouldn’t be commenting when I haven’t read everything, but being ill-prepared has never stopped me before. :) I just wanted to point out that the SSRs that I see in that image are single-pole. Since I keep seeing the term ‘mains’ for power, I’m assuming this is running in Europe somewhere on 220V, which would imply that it’s not split-phase, which in turn means that you’re only stopping half the supply to the device. This works, but it leaves the device in a state where it’s ‘off’ but can still shock someone who messes with it. Yes, if they have a brain they will unplug the device before messing with it, but it’s Good Practise to interrupt both sides of a full-phase feed. Just sayin’.
        Secondly, those SSRs don’t have heat sinks. Did you check to make sure they can handle the full amperage without heat sinks? The heat sinks are sold separately….


        • Ren says:

          Just because 220 VAC in the USA is “split-phase” doesn’t mean that in other countries it is obtained that way. I too may be ill-prepared to state the following, but I believe “their” 220 VAC is single phase, just like “our” 120 VAC is single phase. The 220 VAC we use at work (here in the USA) for testing the products we send to “there” is 60Hz as opposed to “their” 50Hz, but the difference doesn’t seem to bother my bosses or the customers.

  6. First off, thanks Mike for mentioning my project. These are a pair of simple 150 watt ceramic heaters you can pick up online or your local pet store (typically used for aquariums for animals like lizards)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


Get every new post delivered to your Inbox.

Join 96,615 other followers