[Ray]

It’s recommended that the 24V AC transformer is rated 500mA or above. If you searched for ‘sprinkler transformer’ or ’24v ac transformer’ on Amazon, there should be some available choices. For example, this one on amazon.co.uk:
http://www.amazon.co.uk/Orbit-57056-European-Transformer/dp/B004RUHA5M/

As long as it’s AC transformer, it doesn’t matter which order you insert the wires — AC has no polarity.

[Ray]

The password has a 15 character limit. I may have forgotten to add a checker in the firmware to check if it’s more than 15 characters. So if you put in more than 15 characters I am sure it will cause a problem. Will fix this in the firmware.

[Ray]

You can find plenty of information by Googling. This diagram shows how the valves are connected to a standard sprinkler controller:
http://www.sprinklerwarehouse.com/DIY-wire-valves-s/6547.htm

Also, you can go to home improvement stores and ask a store person to help you.

[Ray]

I am pretty sure the Adafruit LCD uses I2C interface (the SDA, SCL lines). You can share multiple devices on the same I2C bus, because each device has its own unique ID.

[Ray]

Cool. Glad to hear that it helped solve the problem. Thanks for sharing your experience.

[Ray]

Did you check the online user manual?
http://rayshobby.net/?page_id=192
Master (or pump) station is a built-in feature of the OpenSprinkler firmware. You can designate any of the first 8 stations as a master / pump station (which turn on when any other station is on), and you can fine tune the timing when the master station turns on.

[Ray]

Cool. Thanks for sharing.

[Ray]

The support pillars are all designed in positions that only touch solder masked regions of the Pi board. So unless if your Pi board has exposed PCB trace (i.e. broken solder mask), the pillars should not cause any shorting.

One potential issue could be the cable that comes with OSPi. A couple of months ago we had one batch of cables that had connection issues, but ever since that batch I haven’t heard any further issue with the cables.

[Ray]

First, you should be careful buying an AC/AC adapter from the US and use it in the UK. The mains here are 110V, and I believe in the UK it’s 230V. If you use the rain bird transformer (110V -> 24V AC) in the UK, it will probably output 48V AC, which will destroy OpenSprinkler in no time.

It’s possible to modify OpenSprinkler to use DC power instead. The power conversion circuit works with DC as is, so no need to change that. However, the triacs need to be replaced by transistors or mosfets in order to interface with DC devices. Flyback diodes should also be added to interface with sprinkler solenoids. On the microcontroller-based OpenSprinkler 2.0, the PCB design has considered these potential modifications (including PCB holes for both transistors/mosfets and flyback diodes). But OpenSprinkler Pi doesn’t have these yet.

The main reason *not* to go with DC is that most sprinkler solenoids are designed to work with AC power. So all standard sprinkler controllers are also powered by AC adapter. Since we don’t make custom sprinkler solenoids, we have to stick to the industry standard. While you can probably operate them with DC as well, there is a liability issue if things go wrong.

So in the end, we can leave these options available, but you have to make your own modifications if you want it to work with DC, well, unless if you can convince me that in the UK market, most sprinkler solenoids operate on DC power 🙂

[Ray]

Cool, looks nice and thanks for sharing.

I suspect it can’t fit all together to the current enclosure, since the enclosure (Serpac 032C) isn’t very high. However, if you have some way of making cutouts yourself, you can get Serpac 033 or 133 enclosure, which has extended height and I believe can fit with the base of 032C enclosure:
http://www.serpac.com/sx3x.aspx
Digikey and Mouser both have these enclosures at very reasonable price.

[Ray]

Some users have asked about power over ethernet (PoE), either offline, or in the old Google Group forum. You are right that it’s not currently supported. I don’t own a PoE device, so I can’t tell what modifications would be necessary to make it work with OpenSprinkler.

[Ray]

Forgot to mention: regarding X1: did you check the build instructions of 1.42u? X1 is not used: it is for fixing the microcontroller fuse bits in case you accidentally set the wrong fuse bits. Normally you do not need it.

[Ray]

Peter, you don’t need to desolder the resistor networks: the values indicated in the part list are correct. Yes, they don’t match the schematic, but those values work too. Let me explain:

RN1 contains 4 pullup resistors. 10K is a standard pullup resistor value.
RN2 is for button detection, since it forms a voltage divider network, any resistor value would work
RN3 and RN4 are current limiting resistors for the triac, either 220ohm or 330ohm works.

You shouldn’t think that there is only one correct value for each resistor: the matter of fact is resistors can often vary across a pretty wide range of values.

[Ray]

First, if power goes out, the sprinkler valves are clearly deactivated, because the valves run on 24VAC from power adapter, they don’t run on batteries.

Next, if RPi freezes, it can indeed leave a valve on. There isn’t a watchdog timer on the OSPi to handle this potential issue. But frankly I don’t know how often RPi freezes. I’ve never encountered this myself.

[Ray]

The first thing I suggest is to check if your controller can successfully connect to your network. If network connection is not available, the controller will try to reconnect every couple of minutes. During reconnection it would appear as if it’s locked up. Setting a static ip can speed up the reconnection time.

[Ray]

Indeed you can use relay. Basically the relay’s data pin will be connected to the shift register, or directly to a GPIO pin if you don’t need shift register. But as I mentioned in another thread, I would still prefer triac because they are significantly cheaper than relay, more compact, and have faster switching speed.

If you are looking for the bare-minimum hardware, the OpenSprinkler zone expansion board is close to that. What you need at the minimum (to interface with sprinkler valves) are triacs, resistors, and optionally shift register (again, if you directly use GPIO pins you don’t need shift registers). On top of that, you need a microcontroller (like Arduino), or RPi to send control command, and an Ethernet shield, or USB dongle to handle web requests. So if budget is a major concern, you can build your own controller at a pretty low cost.

[Ray]

You are right, the firmware currently does not automatically detect DST yet, so you need to manually change the time zone. This shouldn’t be too hard to add, and I will try to get this feature included in future firmware update.

[Ray]

The software assumes that the start time and end time are specified for the same day, so 6:00 is prior to 23:00.

[Ray]

The error says it all: Start time must be prior to end time.

If you are trying to run a program over midnight, you can set the program end time to be 23:59. Once the program starts (say, at 23:00) it will continue running until all the scheduled stations have completed, even if it runs over the end time (23:59).

[Ray]

@kkpwr&h2o wrote:

When I go to http://rayshobby.net/apps/sprinklers, the app opens but I am unable to add a new device when using my IP addr 71.85.xxx.xxx:8080. After I hit the Submit button I keep getting, “IP Check IP/port and try again”.

Port 80 is forwarded on my router (and as I read in above posts, it being used by apache by default) so I am thinking that is the port the local OpenSprinkler web page is using.

Since you are using port 8080, you need to forward port 8080 on your router, instead of the default 80, right?

[Ray]

We don’t provide pump and valve. You need to purchase these separately. Most sprinkler valves are standardized, so they are typically interchangeable. On OpenSprinkler, the maximum current per channel / station is 800mA AC continuous, and 8A impulse (inrush).

[Ray]

I think the label ‘AC adapter’ here is a bit misleading. This seems clearly a DC adapter (or more strictly AC to DC adapter). Note the label that marks the – / + of the connector.

Another way to tell is to use your multimeter to measure the AC voltage of the output of the transformer. If the transformer outputs DC, the AC voltage reading will be almost zero.

You will need an AC adapter, such as this one:
http://www.homedepot.com/p/Orbit-Transformer-24V-750Ma-57040/202899607#.UfWLPReJBpl
You can also search ‘sprinkler transformer’ on Amazon and there are plenty of choices.

[Ray]

Check if your transformer is 24V *AC*, not DC. If it’s a DC transformer, you will only be able to turn on valves and not turn off. This is due to the way triacs work.

[Ray]

To be honest, I am confused what exactly you are trying to do. My guess is that you are trying to pair two stations together, and make sure that they always come on together, is that right? If so, why not just hard-wire the two stations together into the same terminal port. Each terminal port can control 2 valves in parallel.

[Ray]

Unlike the microcontroller-based OpenSprinkler, OSPi’s firmware programs do not actively set and read RTC directly. Instead, you should set it up with the RPi’s operating system in order to automatically set and read RTC. The OSPi Wiki page has instructions:
http://rayshobby.net/mediawiki/index.php?title=OpenSprinkler_Pi

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