I'm not sure you understand what's being discussed here. Esphome is meant to control a number of switch entities. The Oto is not a water valve controller and requires a custom firmware to accomplish any of this.
Honestly just being able to setup a watering zone is all I need. Handle everything else in HA
I actually understand things quite well and have no problems keeping up on the conversation which is the reason for my lengthy post...... people are fantasizing about a built from scratch firmware alternative for their Oto controllers because they dont like the direction coming from corporate updates and using cloud........
My comment was specifically questioning/arguing why someone would build new firmware from scratch and has the capability to integrate with Esphome and Homeassistant when there is already firmware available because of Esphome and the fact that most if not all Oto controllers already use an esp32 board and one only needs to connect some jumper wires to it and reflash it using the already existing Esphome Sprinkler Integration firmware that already meets 90% of the listed functionality desired so, if there's already an Opensource option available that has 90% of the feature that you want then why would you then choose to build something from scratch instead???
Also, to state this, it makes me think that you might be the one who's misunderstanding the capabilities already available because Esphome is far more capable of just controlling some switch entities and could be used to buid a far superior controller firmware that does everything you want it to do and then some more....
The problem with over relying on Homeassistant and putting all of your logic/automations inside of HA and especially for things like this that already have the capability to be integrated into HA while also maintaining its own ability to process logic/automations 100% independent of needing to communicate with HA or the internet to maintain functional because its capable of working completely solo and work locally incase there's ever an issue with communication with HA or whatever cloud service you intended to use and isnt working either.....
If something is capable of working 100% without HA then why would you want to make it 100% dependable on being able to communicate with HA for it to work at all??? By using Esphome like ive been mentioning then you get the best of both worlds because it fully integrates with HA while maintaining its capability of working completely independently of it and can be controlled completely independent of HA locally??
I think there may just be some confusion around “open source” vs “ESP32-based.” Having an ESP32 inside doesn’t automatically make the firmware open source or publicly flashable.
That said, if you’re willing to share the ESPHome port/repo once it’s in a usable state, I think a number of us would be really interested in testing it out. Even if the initial setup requires UART flashing and is considered “advanced user” territory, the HA community is usually pretty good about helping document and refine these kinds of projects.
I didn't realize it was that easy to just flash this with esphome and I'd try it out if so.
Otherwise I'm really interested in the reverse engineered firmware where I can control my own device.
I've reversed engineered the Oto hardware. I have written my own firmware for the Oto hardware from scratch.
The original firmware and the App are really quite good.
Unfortunately it needs the cloud to operate and its not compatible with Home Assistant and I want it to do more.
Wow - great to see such attention to your project!
My unit died when I tried to restore from Winter mode. I had v1 hardware, and I think it may have issues with cold restore when the battery is dead. (Support declared it dead.) I plan to see if I can resurrect and use for your project :).
Regarding enhancements - I wish it would provide a more spray or mist mode. I realize that alters the spray dynamics, but the standard stream is a bit rough on my wife's flower bed. i have considered 3D printing something ... but need a 3D scanner to size things up.
At any rate, where is your GIT repo? even if you aren't accepting contributions I would love to tinker myself. 
My repo is up but not public yet. I have a few more tasks I want to complete before I release to the wild. Even then, I'm confident there will need to be some improvements.
I would definitely look into fixing that Oto that failed. Its not that hard to get into and if it just needs a replacement 4000mah battery that's easy. I can't imagine what else could go wrong.
Oto as it is, the nozzle is fixed however, the nozzle can rotate faster than it typically does in the Oto firmware. It can also be programmed to waggle or circle when spot watering. That reminds me, that's something I haven't done yet. With the source being open you could certainly change the nozzle. You'd have to recalibrate the pressure / valve and you would have to do some bucket measurements to get accurate deposition rates. Definitely doable.
I still need to write some instructions to help others easily get into the Oto to flash the firmware the first time. Once you know what to do it's pretty easy. Only the bottom plate needs to be removed by unclipping two snap clips and then there is a small rubber plug visible that can be pulled out gently. The plug has a little loop at the inside end that the UART cable, bent in half, runs through. The cable pulls out with the rubber plug. You gently find which end is loose and pull that out. The end has a 5 pin JST SH connector. I'll provide instructions on how to make a 3.3V USB UART cable also. Making the cable is probably the most challenging part. Easy if you have some basic soldering skills. Once you can connect, its easy to backup the original flash in case you ever want to go back to it.
I would advise anyone thinking of using this new firmware that if Oto finds out you changed the firmware they would probably void your warranty.
Yeah, I presume modifying in this way would void the warranty - hence why I am starting with a failed device. (Hoping I can replace battery and get it back working..)
I have the cable exposed but need the MOLEX connector on the other end. Cables should be here tomorrow and then I'm going to take a go at replacing the battery, dumping the firmware and proceeding to tinker.
I'm thrilled that this project is getting so much attention and progress. If you need another person to test or contribute, I'd love to be added to the repo. @c6fc on github. I currently have a brand new device that I'm not reliant on yet, and planning to get a second-hand unit for tinkering.
Word for the wise - these units are definitely NOT designed to repair (e.g. to replace battery). Even after "managing" ... I'm not sure there is any getting the ghost back in the machine once I get the board working.
On the plus side, more than happy to take any pictures of the innards for those curious.
Wow, yours has the valves. None of mine do. They definitely made it challenging but once you know its secrets, not too bad to open up. I notice you don't have the nozzle dome removed. If your unaware, on the top there is a little plastic disc that is attached with pressure sensitive adhesive. It can be pried off with a small spudger if you heat it gently with a hot airgun it comes off even easier. Underneath the Oto label disc is a screw to detach the dome.
Ahhh! I wasn't able to remove the nozzle (for fear of breaking it) but that will be necessary to put it back together. Are you saying I need to pry this part upwards/heat gun it? (Sorry for so many questions, and thanks for the tip!!)
It is a pretty tight fit in the sprinkle assembly itself with all 3 valves. If I can get your FW going that is one of the features I was hoping to revive - such a great idea.
Cheers
/Mas
No. I have not figured out how to pull that part out of the assembly. I was concerned I'd break it. I was only referring to the dome. The actual nozzles are on the face of the white piece in your image.
On mine the top white lollypop piece has a stem that goes into down into the top of white stem shown in my photo. That way the main valve can be separated from the lollypop stem. Inside the top white part in my photo is a o-ring.
There is no "open source vs Esp based" comparison, not one bit. Open source just means someone made it(firmware, software, an app, etc) and they attach an "Opensource license" which means it is free, can be shared or modified by anyone as long as they agree not to try and monetize it by using it as or in a for sale product/service. There is every category of open source software available online and one of them is for esp boards.
Having an esp32 inside means that any individual can upload their own firmware or use some open source firmware like Esphome Sprinkler which is 100% free to use.
Well, all you had to do was ask someone or you could ask me and I only charge $49.99/hr for "handsome tech support services!" ; ) jk.
ESPHome Sprinkler can sequence switches/valves, but it doesn’t automatically know Oto’s nozzle aiming, distance calibration, pump behavior, flow/pressure sensor, or motor positions. Has anyone mapped the GPIOs or confirmed how Oto controls aim/distance after flashing ESPHome? I’ve been researching this too, and it seems like there would need to be a pretty custom layer beyond ESPHome Sprinkler to recreate Oto’s targeting logic thus still needing very custom firmware or addon.
Github repository open very soon. GPIO's all documented. HA automations and starter dashboard included. I have 2 more things I want to finish before I open to the public. I have to include multi-device support in HA and I need to create some basic instructions on how to get into the base of Oto. Relatively easy to get access to the UART once you know how. I look forward to others contributing and providing feedback.
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That's because Esphome Sprinkler was originally created for your typical irrigation systems with individual heads, multi-head zones, incorporating pump/s if necessary and then setting schedules, timers, basic and advanced controls, etc, etc.
If you wanted to continue using your Oto device's then someone will need to map where each gpio goes and whatever its connected to like a pump, servo, valve, sensors, etc etc. Once that is done then youll need to manually configure those things as additional Esphome Integrations or sensors and it should be pretty straight forward but, I honestly dont know why anyone would want to do that when you can just replace it with an adjustable above ground sprinkler head that you can adjust the spray distance, the output spray pattern and then set the Left/Right limits or remove them to make it do 365 degree rotation. It would be way simpler that way, which is exactly how the majority of systems currently work already and theres no need to program the heads because they're all mechanically set and once they're set then they're good to go all year.