# JLCPCP Help - Owl Relay Hat **URL:** \ **Category:** Hardware\ **Created:** [December 19, 2025, 5:54pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25 "2025-12-19T17:54:12Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [December 19, 2025, 5:54pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/1 "2025-12-19T17:54:12Z")
Hi Everyone! Thanks to Guy Coleman for making this all possible. I am working on a 30 foot, front tractor mount rig for green on brown detection. I will assemble 10 units for this project. I am attempting to order the official owl pi hat through JLCPCB and am getting an error on the BOM/CPL page. Can anyone tell me what I am doing wrong? ![image](https://community.openweedlocator.org/uploads/default/original/1X/4d07d9edfd2916dfb55d4455fac9e2ee51c1d742.png) TIA Alex Armstrong ---
**Author:** ![geezacoleman](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/g/c6cbf5/32.png) [@geezacoleman](https://community.openweedlocator.org/u/geezacoleman)\ **Post date:** [December 21, 2025, 5:45pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/2 "2025-12-21T17:45:36Z")
This is a really cool project! I will put up a post sharing how we managed the power across 12 units. It’s pretty much just a bunch of car relays managing each OWL. You might have a better solution here. We also run an enable switch from the controller to each EN on the boards, giving you a hardware-based shutoff at the end of each run/wherever. In any case, definitely share your progress - I know there are quite a few who would be interested in what you find. Happy to help at any stage here as well. How are you considering doing the networking/control of all the OWLs from thr cab? We used a Teltonika RUTX14 industrial wifi router to cover the 12m/36ft and it worked quite well. You could also run a hardwired ethernet network up to a switch in the cab - likely more reliable but a bit more work. All this setup is automated with the owl\_setup.sh script in the wireless-display branch, or the controller\_setup.sh if you’re setting up the controller itself. As for the JLC errors @blinken would know more about it. You can also purchase the boards directly from his [site](https://paradar.co.uk/products/owl-driver-board-raspberry-pi-automotive-relay-hat?srsltid=AfmBOoou4oeY3zM0wiALeIy0ziCsE_mdu9hmwZjkJ1fLjOgwgOySD3sI), but likely more expensive than having 10 built yourself. ---
**Author:** ![geezacoleman](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/g/c6cbf5/32.png) [@geezacoleman](https://community.openweedlocator.org/u/geezacoleman)\ **Post date:** [December 22, 2025, 1:11pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/3 "2025-12-22T13:11:59Z")
If it helps - here are some images of the current controller design. The architecture is basically: 1. [RUTX14 router](https://www.teltonika-networks.com/products/routers/rutx14) sets up a wifi network across the boom/cab 2. The controller Raspberry Pi runs as an MQTT broker and a separate flask app in kiosk mode 3. All the OWLs will automatically connect to the network on boot and start publishing/subscribing to the relevant MQTT via the broker. 4. The switches on the bottom, control GPIO pins on the controller PI and one controllers the EN pin to all OWLs for a hardware-based control. The design means you can stream video and update all settings remotely, without need to run ethernet cables to every device. It is very helpful for managing larger numbers of OWLs. ![20251103_221137](https://community.openweedlocator.org/uploads/default/original/1X/b093cbf52eeaa31237582690e8b1e06410396c9d.jpeg) ![20251104_134722](https://community.openweedlocator.org/uploads/default/original/1X/65053521ad4d5880e58a18e398624a941fceced8.jpeg) ![20251104_134738](https://community.openweedlocator.org/uploads/default/original/1X/186519e01e9d53319d23fefd0db604c680126265.jpeg) ![20251104_135124](https://community.openweedlocator.org/uploads/default/original/1X/1a7087f8fa3433f7f8f0743b81d882f862e7ee7e.jpeg) ![20251103_110626](https://community.openweedlocator.org/uploads/default/original/1X/17cf1fd7812b101f1d5eac9df5fcf0a565348a65.jpeg) ---
**Author:** ![geezacoleman](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/g/c6cbf5/32.png) [@geezacoleman](https://community.openweedlocator.org/u/geezacoleman)\ **Post date:** [December 22, 2025, 1:36pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/4 "2025-12-22T13:36:26Z")
To answer your original question - those warnings can be safely ignored. They are for some pick and place alignment contacts that don’t exist in the JLC library, which isn’t really too important. So you can ignore them and proceed if you need to. ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [December 22, 2025, 7:20pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/5 "2025-12-22T19:20:17Z")
Great, thank you! I will try to proceed. I have already ordered 5 of the 10 that I will need from you guys at [Paradar.com](http://Paradar.com). I already have one unit built, using your custom relay hat. I really like the design. ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [December 22, 2025, 7:50pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/6 "2025-12-22T19:50:40Z")
I think I may attempt to copy this, it looks very neat and efficient. This rig will be a standalone, tractor mount as my initial use will be green on brown. We have a problem with glyphosate resistant ryegrass, but it emerges in early spring, surviving early season burn down. If this is successful I may implement green on green use in soybeans to kill resistant pigweed and water hemp. My current plan is to front mount, giving me ample room to move the owl unit ahead of the spray bar to possibly increase speed. I was initially going to use a switch box PCB designed by @sk21 on Agopengps. His design uses a arduino nano, however I think the code would require some revision as it was made for integration into AOG. I was also considering this - [GitHub - Xilofeon/Section-Control-for-AgOpenGPS](https://github.com/Xilofeon/Section-Control-for-AgOpenGPS/tree/main) I was going to just wire in three section using the EN option on the R Pi and a simple switchbox and relay board, with a master switch to control all 10 units. However I like your wireless option the best and think I will pursue that. I am just now building the remaining 9 units and had not really thought about controls and wiring. I have no professional training in the use of coding or microcontrollers. I have a basic knowledge of electrical theory and python. I have a bachlors in business and have been farming for the last 10 years. Your design is very straightforward and easy to understand. I hope that I am an example of the average farmer that can implement your design easily and on a budget. I am trying to keep total costs below $ 5,000 American. In regards to the pressure drop issue, I think I will plumb in a 1/2” supply line using these 3/8” solenoid valves: [3/8" Solenoid Valve - 12V DC Stainless Steel Electric Solenoid Valve , – U.S. Solid](https://ussolid.com/products/3-8-solenoid-valve-12v-dc-stainless-steel-electric-solenoid-valve-normally-closed-viton-seal-html) I am looking forward to completing this project, I will start a thread with build progress here. I am sure that I will have many more questions. Thanks for all of the work and support, hopefully I can contribute something to the project as well. Regards, Alex Armstrong ---
**Author:** ![phil-bluegums](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/p/f475e1/32.png) [@phil-bluegums](https://community.openweedlocator.org/u/phil-bluegums)\ **Post date:** [January 4, 2026, 7:22am UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/7 "2026-01-04T07:22:08Z")
Hi Alex. Great project. I am also hoping to build a spray boom for spraying Bluegum regrowth. Mine will hopefully end up with 4 Owls to cover 4 rows of stumps. (approx 18 mtrs) I like you am a humble farmer with an inquisitive mind and in my case, zero knowledge or experience in this space. Where are you based? I am in SW WA. Would like to bounce some ideas of you at some stage if thats ok. ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [January 4, 2026, 1:59pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/8 "2026-01-04T13:59:39Z")
Hey Phil! Thank you, my project seemed a little overwhelming but now that i am building the OWL units it seems to make a little more sense. I just read through the thread with you and Guy discussing your project. I too am a farmer with no formal training on microcontrollers/python/algorithms etc. I am about 40, so I remember using MS-DOS before Windows was the OS of choice. I am located in West MS, in the Mississippi River Delta. I farm primarily soybeans and corn, wheat on occasion. What’s on your mind? ---
**Author:** ![phil-bluegums](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/p/f475e1/32.png) [@phil-bluegums](https://community.openweedlocator.org/u/phil-bluegums)\ **Post date:** [January 5, 2026, 10:11pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/9 "2026-01-05T22:11:41Z")
Hi Alex. Thanks for the reply. I am about to order the components for the OWLs and will likely have to reach out for some help getting them set up. As I live in the south west corner of Western Australia, it will be difficult to visit and observe your sprayer. Once my components arrive, I’ll open a build thread and try to share the experience. ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [January 6, 2026, 12:11am UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/10 "2026-01-06T00:11:23Z")
I will open a thread with a few pictures as well. I thought you were in the U.S., I actually read that as Southwestern Washington State. I am assuming that is actually Southwestern, West Australia? I will attach as many pictures as I can, and will be more than happy to send you any additional photos and videos. I am still smack in the middle of unit production. I will soon be constructing the wireless controller referenced above. Will you be 3D printing or using the aluminum housing? ---
**Author:** ![phil-bluegums](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/p/f475e1/32.png) [@phil-bluegums](https://community.openweedlocator.org/u/phil-bluegums)\ **Post date:** [January 6, 2026, 12:35am UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/11 "2026-01-06T00:35:08Z")
I have been busy filling a basket with a shopping list from Guy. In the process, I have just made a decision to put a hold on my project pending the release of OWL 3.0 Some unavailable items and with OWL 3.0 being close, I may as well wait for the latest version. I do have another idea for a light mechanical arm that will trigger a limit switch as it rides over the top of the foliage. It may struggle with uneven height. ![image](https://community.openweedlocator.org/uploads/default/original/1X/dd7c885514a13e23ab0114a8d1e1f404504e6719.jpeg) ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [January 8, 2026, 1:23am UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/12 "2026-01-08T01:23:27Z")
Had I not already purchased the R Pis I would definitely wait on the OWL 3.0. The overheating issues should be solved and the R Pi Compute is a much more compact SBC. I really like this switch, it reminds me of the “whisker” switch on some sprayers, combines and cotton pickers. How close are your tree stumps when moving down the row? Could you install a fast valve in front of the boom, and shut the boom off between stumps? ---
**Author:** ![phil-bluegums](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/p/f475e1/32.png) [@phil-bluegums](https://community.openweedlocator.org/u/phil-bluegums)\ **Post date:** [January 8, 2026, 9:51am UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/13 "2026-01-08T09:51:26Z")
Tree stumps are 3 -5 mtrs apart with some gaps up to 10 mtrs. And yes the plan is to have the soloniod valve turning on and off between stumps. I plan to incorporate the switch (above) into this process. A chemical saving of 40 - 50% may be achievable. ---
**Author:** ![Alex](https://community.openweedlocator.org/letter_avatar_proxy/v4/letter/a/db5fbb/32.png) [@Alex](https://community.openweedlocator.org/u/Alex)\ **Post date:** [January 8, 2026, 1:02pm UTC](https://community.openweedlocator.org/t/jlcpcp-help-owl-relay-hat/25/14 "2026-01-08T13:02:58Z")
I guess what I am asking is: if you are worried about the switch activating the OWL when you dont want it to, could you just shut off supply to the boom until you get close to another stump. Thus letting the solenoids open at will but nip apply any spray where you dont want it. You mentioned varying heights of growth being a problem with your switch. Im making the assumption that growth between stumps would activate your switch when you dont want it to. For instance I will be splitting my 12 row boom into three, 4 row sections. Before I saw Guy’s controller setup, my plan for section control and quick deactivation/reativation was to simply turn off supply and run the solenoids “dry” to prevent unwanted application.