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A new way to control water!

h20 Shield

Update: I've updated the design of the board and the transistors used to ensure better compatability with the Orbit valves. I was getting reports from folks that some valves would open but not close with the shield. The updated design can be downloaded at the bottom of this post.

I've been working on a rather large project for some time now and while my new h20 shield is just one piece of the larger project, I thought it deserved it's own post and documentation. I can see this shield being quite useful for lots of folks wishing to control water using one of the fairly inexpensive Orbit 62035 garden hose valves.

First, allow me to give credit where credit is due, the hard work for the control circuit and voltage booster came from this incredibly smart gentlemen and the shield wouldn't be possible without his hard work figuring out how to control the valves! His design for controlling the valves works wonderfully!

This shield is a three valve controller with LED indicators for valve status. I used the long headers thinking I'd make the shield stack-able but the 50v cap scrapped that idea. If I make another version, I'll use a different cap/layout to ensure you can stack this shield, as it now, this will just be the top shield in my project. I also used only through-hole parts (I normally would have used nearly all SMT components) to make the shield easier for folks to solder and I had many of the components in through-hole package on hand.

h20 Shield

The circuit is quite simple really, it's comprised of two main parts, the 24V voltage boost circuit which is required to open and close the Orbit water valves and three open/close control circuits. The shield uses 7 digital pins and 3 analog pins. I have one pin each for open and close for each of the three valves, they each drive a transistor which close the 24V through one of the two valve connections. One will open the valve and the other will close it. The final digital pin is used to control the LT1303, when held high, the circuit will shut down thus saving power as the 24V is only needed when opening and closing a valve. I've used the three analog pins to control the LED indicators for the three valves, I needed the other digital pins for other shields that are part of the bigger project I mentioned earlier.

I got the 3.5 mm connectors from and the rest of the components I either had on-hand or purchased through

I've included high-resolution pictures of the completed board along with the Eagle schematic and board files and a sample Arduino sketch for those interested! As you can see from the video below, the board works perfectly! If you find a use for this design, let me know, I'm always fascinated by how folks use controllers like this!



h2o shield Project Files
Title: h2o shield Project Files (625 clicks)
Size: 13 MB

h2o shield Project Files
Title: h2o shield Project Files (625 clicks)
Size: 13 MB

Comments (35) Trackbacks (2)
  1. Hey, just wondering if you could make me one of these?

  2. Sure, $20 US plus shipping from USA and I’d be glad to make one for you.

  3. How do I contact you?

  4. Any chance I could persuade you to make one more..?

  5. Add me to the list of clients!
    I could use a shield with 4 or more outputs also 😉

  6. Jay, would you be willing to produce two of these for me? If so, please send my your info so we can get this started. Thank you!

  7. Just wanted to update everyone that I’ve sold out of the shields for now. New shipment of shields should be here and ready to ship next Friday (6/16/11). I’ve also had to raise the price just a bit to cover my costs of parts and assembly (hand built and tested). The new price per shield is $30.00 US plus shipping.

  8. I would be interested in at least two of these. And maybe a third unassembled so I can pretend I know what I am doing 🙂

  9. Just wanted to let everyone know that there are some valves that seem to not want to close with this shield. It appears that those valves that don’t want to close have a different resistance between pins 1 and 2 (the base of the plug and the center). I’m working on a solution to this, in the meantime if you have a valve that will open but not close with the shield and works fine with the Orbit controller, please let me know what resistance you measure between pins 1 and 2.

  10. Plenty of boards are available now for anyone who wants one.

  11. Jay, I’m interested in the PCB. can you let me know how much it cost for the PCB alone? Also I don’t see the link for the schematics in your post.

  12. Sorry about that. I updated WordPress and it nuked my attachments, it appears…I’ve attached them to the post again. $5.00 US per board which includes shipping anywhere in the USA via USPS. I’ve got about 20 of them, so let me know how many you want.

  13. Jay,
    Thanks for uploading the file. please let me know your email address or email me at pmreghu at yahoo dot com

  14. I’d love to buy 3 of your assembled boards (or the bare boards if that’s all you have). How can I go about that? Can I PayPal you? My e-mail addy is

  15. Bruce,

    I only have the boards left, I sell them for $4 each and free shipping via USPS postal mail. You can send payment and your address via paypal. I’ll email you the paypal address.

  16. Hi,

    Very interested in a [built] board. What is current availability?

  17. Hi Jay,

    Were you able to fix the problem you reported over at Ray’s blog (some valves not closing)? If so, would you happen to have some PCBs left? If you have some I am very interested in buying two right away (watering season is about to start). I am about to place a SparkFun order and would like to include some of the parts needed to assemble h2o shields. If you could email me to let me know either way that’d be great. My email address is obviously in my profile for you blog.


  18. Has anyone found replacement (rebuild) kits for the valves? In the hot summer here the rubber tend to mold itself a bit. Then after 1-2 years the valves stop sealing properly. These valves use the water pressure to help seal itself (off). Just curious if anyone has sourced the parts. I’ll checkout the links on the page 🙂 Really only a diaphragm and a rubber valve that goes to the solenoid to replace if they can be found 🙂 Thanks!

    p.s. awesome project!

  19. Hi,
    I have both 62035 and 91592 control valves. Will this be able to control both valves?

  20. @gooseflight: Nope, I sold off all the completed boards and the raw PCBs as well.

    @eloy: I was able to resolve that issue, was just a matter of ensuring enough current could be dumped through the coil to activate it, the transistors used in the original build were replaced with a few other minor parts and I never got any further reports of coils not closing. The schematic on the site is the latest.

    @David Burkhardt: Thanks for the props, I’ve actually not had time to implement this board in my final project yet, we extended our family with a wonderful new baby boy so I’m a bit preoccupied. I have plans to use this shield with my wifi shield and create some smart software to really up the sophistication!

    @rahul: I haven’t tested this design with the 91592, I suspect they connections to the valve would be the same but you’ll need to verify, coils are fairly forgiving so unless those are a complete redesign, this would work. That being said, I’ll reiterate, I have torn one of the 91592 apart yet.

  21. Thanks Jay. Please let us know here (I’m subscribed to this discussion) if you end up ordering more PCBs in the future.

    Congrats on the new member of the family.


  22. Any chance one you have anymore of these shileds?

  23. Lo folks. Thanks for the help figuring out the Orbit valve. I am using a bunch for my plantings when we vacation over the summer. I have not fired up my test design yet, but noting that you all are using a voltage source to drive the coils. Easy enough, but you may want to consider doing it with an inductor. A flyback style boost converter would provide a controllable current at a voltage whatever is needed to force the current. You may be able to such the current needed from the batteries without a boost cap, if they have a low enough resistance. I expect to try it that way, just to be different.

  24. So, I followed your schematic and have everything working with the exception of the audio jack. The solenoid valve has only 2 wires but the connection to the female audio jack has three connections. The 24v doesn’t connect to anything. How did you solve this problem. Am I missing something very obvious?


  25. @Tyrel: The audio jacks must have three connections one is VCC and the other two control the latch in the valve. One will pull the valve latch closed and the other will open it. The Orbit 62035 vales have three wires as it’s a latching valve. Not all water valves will have this type of design and may have a valve design that requires the coil to be continuously charged to keep it open. Do you know which type of valve design you have?

  26. Do you still have any of these available? I would be interested in one!

  27. how can i contact you? i havent heard back since my jan 1st post

  28. Sorry, sold out of the boards. I’m going to build a new version to support the more commonly available valves.

  29. do you have any idea as to when that will be? i could *really* use one!

  30. could you email me your email address so i can talk to you?
    jdubuke gpdservices com

  31. I’ve looked at the attached photos and schematics, but I’m having trouble finding some of the components you’ve used online. Could you provide the part numbers or a little detail on the components to help me find the same ones you’ve used? (I’m relatively new to circuit building and am afraid I’ll get the wrong parts). I now have several Orbit valves, but I’m trying to get the 24 V power supply built which can run off an Arduino. Alternatively, could you provide an idea on when your new H20 shields will be ready?

    Thanks for all your great info! Sites like this make this a very fun hobby!

  32. Jay,

    I am interested in constructing a device to check and level the water in my pool and am desirous of using a Raspberry Pi to do it, though would be fine with an Arduino too (I just know very little about the Arduinos). I suspect that any solution that uses GPIO pins could certainly be retrofitted to work on the Pi anyway.

    The Orbit valve is perfect as I fill my pool from a hose right now and your board would control a valve that would allow water into the pool. However, what I need to devise is a manner to detect when evaporation has caused the water level to fall to a point I wish to add more.

    If this device was able to also detect the pH level and/or temperature of the water, all the better!

    Any ideas?


  33. I wanted to see if you had come up with a new prototype yet or might be able to sell me one of your old boards. I’m trying to automate some of my greenhouse and this kind of shield would be very handy. I’d be okay without in shield format too if I could connect it via pins / screw terminals.

  34. Can I get the Shield with the valve without the arduino

  35. Hi Jay,
    Great post/information on this topic. I ordered the parts in your 14/07/21 schematic and put it all together on a breadboard (unfortunately it doesn’t open/close the Orbit 62035 valves I have, but I’m in the early stages of checking things out; voltages seem to be ok but not going low enough on the open/close lines I guess).
    My question – so you still have any of the PCB’s left?

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