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  • OpenSprinkler Beagle kit is available for purchase at Rayshobby Shop.

Following the sneak-peak preview, I am excited to announce that OpenSprinkler Beagle (OSBo) v1.0 is now officially released! OpenSprinkler Beagle is an open-source sprinkler / irrigation extension board for the BeagleBone Black. It uses four GPIO pins to control an unlimited number of sprinkler valves. Using this board, you can easily convert your BeagleBone Black into a low-cost, web-connected smart sprinkler controller. You can use online weather data to help regulate sprinkler water time, and remotely change settings and programs when you are traveling away. Best of all, it’s an open-source project — you are welcome to tinker with the hardware and/or software to create your own customized sprinkler controller.


The idea of OpenSprinkler Beagle came from the OpenSprinkler Pi, which is a sprinkler extension board for the Raspberry Pi. Since OpenSprinkler Pi was released earlier this year, it has been a very popular product. Over time I’ve received requests from users to develop a similar board for the BeagleBone Black. While the BeagleBone Black is similar in nature to the Raspberry Pi (i.e. both are low-cost embedded Linux boards), it offers some interesting benefits such as a large number of GPIO pins, build-in analog pins, build-in eMMC, microSD card slot (i.e. smaller profile). faster CPU etc. Undoubtedly it makes sense to develop an OpenSprinkler variant for the BeagleBone Black.

The hardware design of OpenSprinkler Beagle is similar to OpenSprinkler Pi: it contains a 24VAC to 5VDC switching regulator, shift register, triac, DS1307 RTC with CR1220 battery, zone expansion board connector. It also currently shares the same enclosure as OpenSprinkler Pi. But it also offers several improvements, specifically:

  • Added a total of 10 bidirectional TVS for protection against transient voltages: one for each of the eight stations, one for the 24VAC port, and one for the rain sensor port.
  • The BeagleBone Black is now plugged down into OSBo, and all GPIO pins are mapped out to the pinout area.
  • Added a 5V mini-relay for more general-purpose switching. The relay has a contact rating of 120VAC / 2A. It can be used for switching low-power lighting, or garage doors etc.
  • The 24VAC terminal block is changed to orange color with 3.96mm pin spacing. This helps prevent incorrect connection to other terminal ports. There is also a solder-on 2A fuse on the 24VAC line.
  • Added a rain sensor port with pull-up and current limiting resistors.

Below is an annotated diagram that shows the various components of the board:

OpenSprinkler Beagle Homepage

Below I am going to give a very brief overview of the hardware and software setups. For details, please watch the tutorial video above, and visit the official OSBo homepage at http://beagle.opensprinkler.com.

Hardware Setup

The hardware is pretty easy to set up. The kit comes with an assembled OpenSprinkler Beagle circuit board, enclosure, screws, terminal blocks, and extra pin headers in case you want to map out additional GPIO pins. In addition, you need to provide a BeagleBone Black, a nano-size WiFi dongle, and a 24VAC sprinkler transformer (these are not included in the kit and need to be purchased separately). The board makes use of the first 2×10 pins on port P9 of the BeagleBone Black for interfacing with shift register, RTC, rain sensor port, and mini-relay. Plug in the BeagleBone Black into OSBo, connect the 24VAC power, plug in the common (COM) wire and individual station wires, and that’s it. The interface is the same with other sprinkler controllers. If you have a rain/freeze sensor, you can connect it to the rain sensor terminal.

Software Setup

Follow the recent update on OpenSprinkler Pi, the software setup for OSBo has also been made a lot easier. Specifically, I’ve created a SD card image with pre-installed software. Download the image, burn it to a microSD card, pop it in to your BeagleBone Black, and you are ready to go. The pre-configured SD card runs a Ubuntu operation system (default user name ubuntu, password temppwd), and sets Dan’s interval_program to start by default. As soon as the system has booted and is up online, you can open a browser and type in http://x.x.x.x:8080 (where x.x.x.x is your BeagleBone’s IP address). This will bring up the interval program’s web interface. The interval program has a rich set of software features, such as setting multiple sprinkler programs, preview programs, run-once program, manual operation, logging, rain delay etc. The details are all explained in the user manual of the interval program.

The SD card has also pre-installed Samer’s mobile web app, which provides a nice front-end for mobile devices such as pads and phones. It is available at http://x.x.x.x/sprinklers.

In addition, there are three demo programs installed in the /home/ubuntu/demos/ folder. There is a self-test program, a relay test program, and a Google Calendar-based sprinkler program, which makes use of a Google Calendar for scheduling water events. I’ve received many good comments regarding the Google Calendar-based program — while it looks simple, it’s quite convenient to use and very suitable for the less technical minded people.

Since the software is pretty much all adapted from OpenSprinkler Pi, feel free to refer to the OpenSprinkler Pi documents if anything is unclear. I will try to make the OpenSprinkler Beagle website more self-contained, and it will have to be polished over time.


In the previous post, I asked for naming suggestions. Thanks to everyone who made comments there. After careful thoughts, I’ve decided to use the full name OpenSprinkler Beagle, and short name OSBo. Particularly, the short name OSBo is picked because it goes well with OSPi (OpenSprinkler Pi), is easy to distinguish with OSBee (openSprinkler Bee), and Bo is a name of a dog. So overall I consider this to be the top choice.

Thanks for reading this post. If you are interested in buying the OpenSprinkler Beagle, we have a limited number of kits immediately available, at the first link below. Feel free to leave comments and suggestions below or at the Rayshobby Forum.


2 Responses to “Announcing OpenSprinkler Beagle (OSBo) v1.0”

  1. sigma says:

    3. OpenSprinkler Beagle
    reffers to http://beagle.opensprinkler.com/
    On the list of products (top left) DOES NOT work.

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