OSBee and OSPi

[Peter]

Hi all,

I am searching for a way to add an internal watering system (Claber Oasis) into my existing OSPi environment and wondered if the OSBee Shield would be an option? The Claber Oasis has a latched 9V DC valve that looks as though the OSBee Shield will control so that much should be do-able but Can the Arduino/OSBee Shield act as either an RF or IP (given the new Unified Firmware release) station for my main OSPi controller ?

I also see an OSBee stand-alone unit on Ray’s Hobby that is “coming soon”. Could this be a better fit?

Sorry for all the questions but would be great to use all the scheduling features of the unified firmware with my indoor system as well.

Thanks, Pete

[Ray]

The current OSBee shield would not work for RPi — because it requires one PWM pin with fairly high frequency to generate the boosted voltage. I don’t know if RPi support PWM or not, and if so, what’s the frequency.

A better design for OSBee shield would be to have a dedicated boost converter, like how OpenSprinkler DC circuit is designed. Unfortunately we are not in the cycle to re-design OSBee shield yet.

The standalone OSBee is temporarily put on hold, partly because 24V AC valves are still more common (than latching valves) on the market.

[Peter]

Thanks for the response Ray. I suspected that the Arduino shield would not be hardware compatible with the Raspberry Pi and thanks for confirming.

So now I am wondering if a networked Arduino with an OSBee Shield could be made to look like a “remote IP station” to my main OSPi controller. This way the Arduino with OSBee Shield could drive the latching valves of my indoor system and my OSPi could drive the outdoor valves and act as the combined central control system.

I know the new “remote IP station” functionality is meant to allow one OS to control another OS. But looking at the 2.1.6 firmware code, the Master appears to be sending just the “cm” command to the Slave. Is that right ? The OSBee web server and sprinkler timer examples look to have all of the component parts of the logic needed to listen for a “cm” command and drive the latching valves. But maybe I’m missing something ?

I’ll admit a somewhat convoluted (and expensive) way to integrate an indoor watering system but maybe I can rationalise it as a learning opportunity !

[Ray]

For OSBee shield we only provide demo code and unfortunately the OpenSprinkler unified firmware does not work out of box for OSBee shield. However, if you have a Ethernet shield or WiFi shield, it’s pretty easy to implement the /cm command so that it will respond to the master controller.

The reason I’ve paused on developing the standalone OSBee is this: the main benefit of latching valve is its power efficiency, so ideally it should be battery powered. However, if it needs to have WiFi / Ethernet connection, then driving by battery is challenging, and so most likely it will still have to be powered by a power adapter. But this defeats the purpose of using latching valves. Besides, latching valves are at similar cost (if not more expensive) than 24V AC valves, and 24V AC valves are more common, so at the moment I am putting the standalone OSBee at low priority.

For users with DC (non-latching) valves, the OpenSprinkler DC version is the best choice.

[Peter]

Thanks Ray for the insight and totally get where your priorities needs to be.

I managed to cobble something together over the weekend using a spare h-bridge chip (L293D) and some unholy hacking on the various code examples out there. To be honest, the hardware was the easy bit compared with getting your head around html and json! Works a treat with my main OSPi controller now sending commands to the indoor watering system.

I agree that the ethernet shield is a bit overkill and makes the unit tethered so will take a look at moving to RF as next step.

[Ray]

“To be honest, the hardware was the easy bit compared with getting your head around html and json” — very true: with the resources easily accessible online, it’s not difficult to assemble the hardware, but the bottleneck is still in software development.

[crossmax]

Hi.
First of all, sorry for this up. Is a old thread.

Peter, I’m in the same situation that you were. I have a latching DC valve, and I want manage it with OpenSprinkler software that run on raspberry pi. I have a motor driver board, L298D which looks like L293D, but I need to configure the valve (in OS settings) with two tasks, one to open and another to close, connecting a motor driver board to 2 GPIO pins.

How did you do this setting into OS code? I suppose you modified the source code, right?

Thanks

[Ray]

If you have a motor driver that’s compatible with latching valve, the software piece should be fairly easy: to open the valve, you apply voltage in the positive polarity (positive to valve’s positive wire, negative to valve’s negative wire), the timing should be about 100 milli-seconds. To close the valve, you apply voltage in the reverse polarity. OpenSprinkler Bee (OSBee) operates latching valves, and you can check OSBee firmware code for reference.

[Author]

Posts