BeagleBone Black project spotlight: Open Sprinkler Beagle (OSBo)

By Tara Stratton

Planning to buy a sprinkler timer for your loved ones this holiday
season? Have no fear, OpenSprinkler is here! Developed by Ray Wang
at Rayshobby LLC, OpenSprinkler Beagle—nicknamed OSBo—was released
last week. It is an open-source sprinkler/irrigation extension
board for the Sitara-processor-based BeagleBone Black. The board
helps you easily develop BeagleBone Black into a low-cost,
web-connected smart sprinkler controller. It comes with a
full-featured sprinkler scheduling program, uses online weather
data to help regulate water time, and enables users to remotely
change setting and programs while away from home. It works with the
standard 24VAC sprinkler valves commonly found in household
watering and irrigation systems and allows for an unlimited number
of water zones to be individually controlled. Because it’s open
source, it offers a lot of flexibility in features and
functionality. Users are encouraged to hack the hardware and/or
software (written in Python, which is easy to learn).

What motivated Ray to create such an innovative and futuristic
project? Ray wanted to provide a solution to the limited set of
fixed functionality and outdated user interface that come with most
commercial sprinkler timers or controllers. Ray even included a
relay on OSBo and hopes it can be used for opening/closing garage
doors as well at some point in the future!

Ray has made several other versions of OpenSprinkler based on other
low-cost computers, but he selected BeagleBone Black for the newest
version to add even more features thanks to the large number of
GPIO pins, built-in analog pins, eMMC, microSD card, and the
high-performance Sitara AM335x processor from TI. The OSBo board
contains a 24VAC to 5VDC switching regulator, shift register,
triacs, terminal blocks, a zone expansion board connector, a rain
sensor terminal, and a mini-relay. It provides 5V power to
BeagleBone Black and uses four GPIO pins to interface with the
shift register as well as SDA2/SCL2 to interface with the DS1307
RTC. The BeagleBone Black computer is oriented face-down, and it
plugs directly into the extra-long male pin headers. The biggest
advantage of the face-down design is doesn’t necessitate cables,
thus there is extra space in the upper-half of the enclosure that
makes it possible to add additional modules. To make it easy to
reuse the available pins on BeagleBone Black, Ray also mapped out
all of the 46 pins on ports P8 and P9 to the pinout area.

Check out the OSBo homepage at
more information or to purchase the OSBO v1 open-source sprinkler /
irrigation extension board. You can also stay up to date on what
Ray is developing on his blog at