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.
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.
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.
For more detail: Announcing OpenSprinkler Beagle (OSBo) v1.0