[Mike]

If you are willing to run wires, you might be able to do something like this relay board with the moisture sensor.  I don’t think any programming would be required, just hook it up like the diagram shows and set your schedule.  When it’s time to water, the relay board will get energized and if the soil moisture is low enough the relay board will open the sprinkler valve.  Pretty slick.

To be honest, cost is the biggest thing I’m struggling with now.  It’s far more expensive than I want and the single highest cost item is the moisture sensor I have chosen.  I do think it’s the right sensor though.  From what I’ve read about the sensors of the type you have linked, they’re not durable.  I’ve never used one though.

I want wireless because of the flexibility and because wire is expensive too.  I’m going to be using it in my gardens and I like to move stuff around.  I might want it in one garden one year and another garden the next or in the tomatoes one week and the dahlias the next.

The XBee has four analog to digital converters – which basically means that I can read 4 values at each remote station.  The moisture sensor will be one of them.  Battery voltage will be another.  I was thinking about soil temperature and a light sensor for the other two values but I’m kind of focused on the soil moisture for now.

[Mike]

Hi Dan,

I just read the documentation you’ve got up there so far for authoring plugins.  I’m running an OSBo and will try my hand at a soil moisture plugin once I have the hardware.  Keep it coming.  Not sure all that you have planned to put in there.  One thing that comes to my mind that I would like to see mentioned is programming environment/tools used.  I’ve programmed in other languages but never in Python.  What tools do you use when you’re working on OSPi?

I know it’s time consuming to author instructions like that, but be encouraged that people are reading it.  Well done!

Mike

[Mike]

I’m still working on pulling together a parts list and planning the details for the sensor side of things.  Here’s my list so far:

Moisture Sensor $37.95  XBee $22.95  Solar Panel $25  Battery $12.50  Solar Battery Charger $17.50  Adjustable Voltage Regulator $5.95 XBee Breakout Board $2.95 some XBee Headers $2 and miscellaneous resistors, wires and an NPN transistor which I have on hand.  This is how I’m thinking I’ll wire it up.  Thoughts?

I’m using an OSBo so I’ll also have to hook an XBee up to my BBB but that should be much more straight-forward with a cape and some stackable headers.

 

Attachments:

1. 

   Diagram.png
   

[Mike]

The VH400 doesn’t measure conductivity.  Sounds like that’s a good thing.  Since it can be buried the moisture differences between drippers can be mitigated pretty well because the water will spread out once it enters the soil.  I definitely agree that the position of the sensor is important, so point taken there.

However, I’d much rather measure soil moisture directly than try to predict it with alternative measurements.

[Mike]

I’m thinking of stackable headers sticking out of the bottom of the OSBo instead of cables.  That’ll mean a new enclosure but I was planning to put the whole thing into an outdoor enclosure anyway.  I’ll start acquiring parts over the coming weeks.

[Mike]

Is there something I can do to help?  I’d love to be able to use a method like this http://blog.fastolfe.net/2011/11/project-wireless-solar-powered-garden.html to hook up the sensor(s)

[Mike]

Thanks Ray!  I’ll probably take you up on your offer after the new year.

I haven’t fully planned out my project yet, but I was thinking of an LCD cape like this one https://www.sparkfun.com/products/12085  It has several conflicting pins though.  It would be nice to be able to walk up to my controller interact with it directly.  I was also thinking about using an XBee to hook up some moisture sensors.  I’d probably use the proto board http://www.adafruit.com/products/572 that I’ve got to hook it up to the BBB.  I really like the idea I found here for the remote end:

http://blog.fastolfe.net/2011/11/project-wireless-solar-powered-garden.html
cached – http://webcache.googleusercontent.com/search?q=cache:http://blog.fastolfe.net/2011/11/project-wireless-solar-powered-garden.html

[Mike]

Is this activity dead?  I just got a BBB and want to incorporate some VH400 sensors into the OSBo (which I don’t have yet).  I don’t want to re-create the wheel or start from scratch if work has already been done on it.

Mike

[Author]

Posts