[RELEASE] Rain Bird LNK/LNK2 WiFi Module Controller

MHedish · November 22, 2025, 8:16pm

[RELEASE] Rain Bird LNK/LNK2 WiFi Module Controller v0.1.0.0

Author: @MHedish
Category: Device Drivers → Utility / Irrigation

Advanced Hubitat driver providing full local LAN control of Rain Bird LNK/LNK2 WiFi irrigation controllers — including zone, program, and rain delay management. Features automatic time sync, telemetry, adaptive refresh, and support for ESP-TM2 and ESP-Me controllers.

Overview

My next abandonware release.

This time, the original author, @craigde, even shared earlier this year that he abandoned his beta driver a few years ago.

I was never able to get that five-year-old code to work, but it did plant the seed for this, and it had a helpful opcode reference for older firmware. Thanks, @craigde!

You should know, this driver is helpful for more than just monitoring your controller; you can use it to integrate any motion detectors and/or event-driven security cameras to automatically deal with folks like this:

This driver not only allows for integrated Hubitat monitoring and control, it addresses a major Rain Bird oversight: time synchronization. The internal real-time clock (RTC) is notorious for drift, yet Rain Bird has no way to automatically update the RTC or for addressing Daylight Saving Time adjustments.

Their solution is either directly through the front panel or manually through the mobile app, despite being Wi-Fi connected (NTP). Not anymore; this driver recognizes DST and automatically sets the controller for you. The RTC is kept within +/- 5 seconds (typically <2) of the Hubitat clock.

All events and telemetry are fully Rule Machine and WebCoRE compatible, enabling precise automation and monitoring with minimal resource overhead.

It communicates directly with your Rain Bird controller over LAN — no cloud, no accounts, no internet dependency.

There are many versions of controller firmware out there, and none of them are field upgradable, so YMMV when it comes to capabilities, but this version of the driver does everything I need it to.

See the Changelog for full release notes.

What’s in v0.1.0.0 (Release Candidate)

Hybrid + Modern Firmware Convergence — validated on firmware 2.9 and 3.2
Switch & Valve capabilities: dashboard integration for on/off/open/close parity
Time sync reliability: hourly drift checks, DST detection, and random offset scheduling to reduce hub load
Deterministic refresh engine: resilient pacing and adaptive polling under watering conditions
Diagnostics: testAllSupportedCommands() now emits firmware and module identity

Installation

Option 1: Hubitat Package Manager (Recommended)

Open Hubitat Package Manager (HPM) from your Hubitat Apps list.
Choose Install → Search by Keyword.
Enter Rain Bird or Irrigation in the search box.
Select Rain Bird LNK/LNK2 WiFi Module Controller from the results and install.
Once installed, open the new device’s Preferences, and enter the Rain Bird Controller IP address and Rain Bird Controller Password. Click Save Preferences.

Option 2: Manual Installation

In Hubitat, go to Drivers Code → + New Driver.
Click Import, then paste this URL:

https://raw.githubusercontent.com/MHedish/Hubitat/refs/heads/main/Drivers/RainBird-LNK/RainBird-LNK-Wi-Fi-Module.groovy

Click Import, then Save.
Go to Devices → Add Device → Virtual, then:

Name your device (e.g., Sprinkler).
Under Type, select Rain Bird LNK/LNK2 WiFi Module Controller.
Click Save Device.

Enter your Rain Bird Controller IP address and Rain Bird Controller Password under Preferences, then click Save Preferences.

Verification

A Configure command will automatically run once you save preferences and will populate that attribute panel.-
Confirm the firmwareVersion and zoneCount attributes populate.
Run a short Run Zone (1, 2 min) test to verify control.

Optional: Diagnostics

Execute testAllSupportedCommands() to validate controller capabilities.
Review output in Logs or driverStatus.

Key Features

100% local control — no cloud API required
Adaptive opcode negotiation for LNK and LNK2 controllers
Auto Time Sync keeps controller time accurate
Per-zone and per-program control with dynamic detection
Rain delay and rain sensor status integration
Telemetry-rich diagnostics and event logging
Cron compatibility fallback — supports both pre- and post-2.3.9.x Hubitat CRON parsers
Designed for Hubitat C-7 / C-8 / C-8 Pro (AES-128 LAN encryption)

Compatibility

Controller	WiFi Module	Firmware	Status	Notes
ESP-TM2	LNK / LNK2	2.1 – 3.0	Stable	Tested on 2.1 and 2.9
ESP-Me	LNK / LNK2	2.9 – 3.2	Stable	Multi-zone hybrid support
ESP-Me3	LNK2	4.0+	Partial	Extended telemetry not yet implemented
ST8 / ST8i	LNK	2.5 – 3.0	Limited	Basic zone control only

Hubitat Platform

Platform	Version	Status
C-7 / C-8 / C-8 Pro	2.3.9+	Fully supported
C-5	2.3.6+	Works (slightly slower crypto)
C-4	—	Not supported

Common Commands

Command	Description
Advance Zone	Jump to the next zone (firmware-aware)
Off/Close	Same as Stop Irrigation
On/Open	Same as Run Program 'A'
Refresh	Force telemetry update
Run Program (A–D)	Start controller programs
Run Zone	Start a zone for a specified duration
Set Rain Delay	Apply a rain delay (0–14 days)
Stop Irrigation	Halt all watering activity

Exposed Attributes

Attribute	Type	Values / Notes
`activeZone`	number	Currently active zone number
`autoTimeSync`	boolean	Whether auto time synchronization is enabled
`availableStations`	string	List of active zones/stations detected
`clockDrift`	number	Time drift between hub and controller (seconds)
`controllerDate`	string	Controller-reported date
`controllerTime`	string	Controller-reported time
`delaySetting`	number	Rain delay duration (days)
`driverInfo`	string	Driver metadata including version and mode
`driverStatus`	string	Current driver health or command response
`firmwareVersion`	string	Controller firmware revision
`irrigationState`	string	`watering`, `idle`, or `off`
`lastEventTime`	string	Timestamp of last received event
`lastSync`	string	Timestamp of last successful time sync
`model`	string	Controller model identifier
`programScheduleSupport`	boolean	Indicates if controller supports program retrieval
`rainDelay`	number	Current active rain delay days
`rainSensorState`	enum	`bypassed`, `dry`, `wet`
`remainingRuntime`	number	Seconds left in current watering cycle
`seasonalAdjust`	number	Active seasonal adjustment factor (%)
`serialNumber`	string	Controller serial number
`switch`	enum	`on`, `off`
`valve`	enum	`open`, `closed`
`waterBudget`	number	Seasonal watering percentage
`watering`	boolean	Indicates irrigation is currently active
`wateringRefresh`	boolean	Internal refresh flag during watering
`zoneAdjustments`	string	JSON string of per-zone runtime adjustments
`zoneCount`	number	Number of detected zones

Diagnostics

Command: testAllSupportedCommands

Tests controller for all supported opcodes and emits results to driverStatus and log.
Also reports firmware and module diagnostics (LNK / LNK2).

Troubleshooting & Common Issues

Symptom	Possible Cause	Recommended Action
503 Service Unavailable	Controller is processing or rate-limited	Allow 2–3 seconds between commands; driver auto-retries with adaptive pacing
Clock drift	Controller RTC inaccuracy	Enable Auto Time Sync (default) to maintain accuracy
Controller unresponsive	DHCP renewal or IP conflict	Reserve static IP for the controller in router's DHCP settings
Zone list empty	First refresh incomplete or older firmware	Click Refresh, wait 10 seconds, then recheck `zoneCount`
Rain delay stuck	Controller cache sync	Run Refresh or Stop Irrigation, then retry command
Sluggish updates	Poll interval too long	Lower Refresh Interval to 2 minutes during active watering season
Repeated log noise	Debug mode active	Debug logging turns off automatically after 30 minutes

Tip: For the most reliable operation, use a reserved DHCP IP and enable automatic time sync.

Best Practices

Time Synchronization

Rain Bird controllers lack NTP or any remote clock-set capability, causing significant drift over time. The driver’s Auto Time Sync function compensates for this limitation by:

Automatically comparing controller time to Hubitat every hour.
Correcting any drift greater than ±5 seconds.
Adjusting for DST changes and randomizing sync intervals to prevent network bursts.

Recommended: Keep Auto Time Sync enabled at all times. This ensures that program start times and watering schedules remain accurate — even after power loss and DST adjustments.

Refresh Interval Tuning

The refresh interval defines how often Hubitat polls the controller for status updates.

Active Season: 2-minute refresh (recommended for zone monitoring and dashboards)
Normal Operation: 5–15 minutes to balance performance and network traffic
Winterized / Off-Season: 60–480 minutes or manual refresh mode
When set to manual, the Automatically sync Rain Bird to Hubitat clock preference will still keep the clock synchronized once an hour while not polling the controller for other status information.
If you choose the Increase polling frequency during watering events option (default), the polling will go up to once every 5 seconds during a watering event to give you almost real-time information. When the watering is over, the polling will go back to the frequency you had set before.

Use shorter intervals during watering periods for near real-time zone feedback.
It's still best to allow the Rain Bird controller to manage automatic watering, but if you want to manage it within Hubitat, you can now use Hubitat’s Rule Machine or WebCoRE to automate watering windows, including the water budget attribute to reduce watering based on the forecasted weather.
Avoid scheduling overlapping zones to minimize command queue congestion.
When creating custom schedules, leave 3–5 seconds between zone transitions for pacing stability.
You can create a routine to update refreshInterval to one minute just before your scheduled watering event and then monitor/record the program status via Hubitat. Set an event for watering==false and then reset the refreshInterval to either 15 minutes or manual.

Security Camera

If you are going to use this to deal with porch pirates, stray animals, or people that can't read no parking signs like the examples earlier, be sure to capture it on video for the rest of us to enjoy.

🖧 Network Stability

Reserve a static IP for your Rain Bird controller in your router.
Ensure the Wi-Fi signal to the LNK/LNK2 module is at least −65 dBm or better.
Avoid placing the module near metal enclosures or irrigation boxes with poor reception.

Following these best practices ensures precise irrigation scheduling, minimal drift, and consistent LAN reliability — even on controllers without native NTP or cloud sync capabilities.

Feedback

This driver has been validated against firmware 2.9 and 3.2. Any other platform additions are welcome.

Please report feedback or findings in this thread to help continue improving the integration, and I can promote this from RC to Production.

GitHub Repository:
Rain Bird LNK/LNK2 WiFi Module Controller (Hubitat Driver)

License: Apache License, Version 2.0
Author: @MHedish
Acknowledgments: Thanks to the Hubitat community developers whose earlier work made this driver possible, including @cragide and @allen.porter.

🩵 Support & Credits

Developed and maintained by Marc Hedish
Documentation by ChatGPT (OpenAI)
License: Apache 2.0

Support development: paypal.me/MHedish

CaptWoody · November 22, 2025, 9:55pm

I've been hoping that somone would try to reserect or create a new app. I am going to install it and give it a try.

CaptWoody · November 24, 2025, 3:55pm

Got a little time today and was able to install and do a little testing. I Executed testAllSupportedCommands and got the following

The warn looks like there is a typo "uri" instead of "url"?

Controller State is showing "Watering" before and after running a zone (tested 1 zone for 1 minute).

MHedish · November 24, 2025, 6:13pm

That's 1) Hubitat's text, not mine; 2) It's not a "typo" URI (Uniform Resource Identifier) is the broader category for resource identification, a URL (Uniform Resource Locator) is a specfic type within that broader category.

Back to the diags... the command support looks good as does the firmware (3.2). The really odd stuff there is the date/time attributes.

Which model controller is this? I tested against an ESP-me

CaptWoody · November 24, 2025, 6:25pm

I learned something today. Thanks.

Mine is an ESP-TM2

CaptWoody · November 24, 2025, 6:42pm

I power cycled it and now it is showing "controllerTime=13:34:25 (13:34:25)", I guess I made it return from the future

MHedish · November 24, 2025, 9:34pm

Progress! The TM2 is a "simpler" controller but looking at the diag you pasted it appears to have all of the opcodes we neeed.

Go ahead and turn on both Enable Debug Logging and Log All Events in preferences. When you click on Save and Close the driver will automatically run a configure() event. That will give us all sorts of info to look at in the debug log.

You should be able run a zone and use stop to cancel everything.

I'm curious to solve the getAvailableStations() error there. Here's what my attributes look like:

CaptWoody · November 24, 2025, 10:13pm

Not sure what happened to the last post. Anyway here they are again.

Ran a zone again and stop. Still shows watering

MHedish · November 25, 2025, 12:15am

That raw data is helpful. I'll dig in to the opcodes and try to figure it out. It does look like the vast majority of the data, including timesync are working but that "4025" for the year as part of the description for controllerTime is perplexing. controllerDate is reading it right

The legacy firmware=2.10 might be a problem. seasonAdjustment shouldn't be all bits on,

When I started working on this, I was surprised at how many changes were made to the firmware that aren't universal.

MHedish · November 25, 2025, 2:49am

Thanks for those logs!

I have some good news and some... less than good news.

The good news is I just finished uploading v0.1.0.1 that addresses four of the items I saw in the logs.

Your actual firmware is version 2.10. I didn't have a controller that old so I couldn't test against it. If you look at the debug log, you'll see that line where it says, “Detected modern firmware 3.2 (replaces legacy 2.10). In reality, you do have 2.10. That was from a logic bug that looked for an opcode response and mistook the very old response from checking for 3.x as positive when in fact, it wasn't.
getAvailableStations() will not throw an error on really old firmware. The best that firmware can do is say, “All of them.”
Now that I know what 2.1 firmware looks like, the seasonalAdjust() response of 65535 has been addressed. It'll max out at 100% instead.
“Watering” has been somewhat addressed. That's the less than good news. Your firmware doesn't accurately report when watering is off. The best I can do is an educated guess.

Firmware ≤ 2.10 never emits updated state telemetry (no valid BF or 3F updates). The best I can do is mitigate that limitation.

Trigger	Detection behavior	Accuracy
My Driver (GUI/RM/WC) starts watering	Immediate update
Controller/app starts watering	Detected from BF=01
Driver stops watering	Heuristic fallback	80–90%
Controller/app stops watering	Not detected reliably	Manual poll correction

If you set the Increase polling frequency during watering events parameter to true (default), the driver will poll every 5 seconds when it detects watering and, hopefully, will know when the watering stops.

If you write your own scheduling in RM/WC, the driver will be, for the most part, authoritative. If you let the controller run the programs, my suggestion is to set the refresh to 5 minutes and then, just before your scheduled program runs, change it programmatically to 1 minute.

Once the program runs, the driver should detect watering, poll every 5 seconds, and detect when it stops watering (80% accurate). Have your rule/piston go back to every 5 minutes when watering==false.

Version 0.1.0.1 is available as a direct download from Git, but I also updated HPM to pull it for you.

Please let me know what else you find, and... thanks for checking it out and the feedback.

CaptWoody · November 25, 2025, 1:17pm

Thanks for the udpate. I will update and see how it goes. Crazy that the firmware for the LNK2 is not getting an update. I got the LNK2 module last March but in the tech world that is old

I'll play with it more and see how it goes.

MHedish · November 25, 2025, 2:25pm

Ah... There's the rub. I have the same issue here. There are actually two pieces of firmware here.

The LNK/LK2 module is a Wi-Fi module only. The module does not control the system; it just provides connectivity.
The controllers themselves (ST8/ST8i, TM-2, ESP-me, ESP-Me3) are what we're actually communicating with. It's the firmware in the controller that matters:

Controller	WiFi Module	Firmware
ESP-TM2	LNK / LNK2	2.1 – 3.0
ESP-Me	LNK / LNK2	2.9 – 3.2
ESP-Me3	LNK2	4.0+
ST8 / ST8i	LNK	2.5 – 3.0

Feature	LNK (1st Gen)	LNK2 (2nd Gen)
Setup	Connects to a smartphone app	Connects to a smartphone app with faster Quick Pair technology, including Bluetooth
Compatibility	Compatible with some residential controllers (e.g., ESP-TM2, ESP-ME, ESP-RZXe)	Wider compatibility: Supports newer controllers, including commercial models like ESP-LXME2 and ESP-LXIVM
Connectivity	WiFi connection	Stronger, faster WiFi connection
Security	Standard WiFi encryption	Uses encrypted wireless communication for enhanced privacy
Advanced Features	Basic remote control and alerts	Includes multi-site management, advanced water-saving adjustments, remote diagnostics, and more robust notifications

My LNK2 module is firmware 3.54. That's just the Wi-Fi firmware.

I have an ESP-Me controller, which only runs firmware 2.9-3.2.

Unfortunately, the Rain Bird controllers are, from my understanding, not field upgradable, so the only way to get newer firmware (and the associated capabilities) is to buy a new controller. The firmware of the LNK/LNK2 doesn't change things.

In your case, that ESP-TM2 is just an old dog that can't learn new tricks.

CaptWoody · November 25, 2025, 2:34pm

Well in the prosses of trying to be smart and figure out how to try to upate firmware, I downloaded the 2.0 app. Connected and it updated the firmware of the module (looks like 4.132 but as you stated controller firm is 1.5.1.
I can access it via the app fine but now I am getting connection refused in HE. I verified the password is correct. Looking

I have to run for a while but when I get back I will see what it is or isn't doing in the HE.

MHedish · November 25, 2025, 4:56pm

The controllers are very finicky. If you ask them to do too much, you'll get 503 errors. I had to put in multiple back-off and retry routines.

I also discovered that if you are logged in to the app, HE will often time out or refuse to connect until you disconnect from their app. I've also seen it the other way, if I'm testing a bunch of things from HE, the app will either report that its busy or will just fail to connect.

Seems they never intended for multiple HTTP connects at once.

MHedish · November 25, 2025, 5:23pm

You made me look...

This FAQ is from Rain Bird's site:

Lock Out

The encrypted password in the Rain Bird mobile app for this controller does not match the encrypted password in the LNK WiFi Module and the user attempted to connect with the wrong password more than 3 times. This locks out the controller from being accessed remotely for 15 minutes.

Controller is Busy

If you receive this message when attempting to connect to the controller, this means another smart device is currently accessing the device. Only one mobile device can connect remotely to the controller at a time.

So, yeah, they chose to not handle two HTTPS sessions at once.

That kind of makes sense. They presumed the only way people would connect with the controller is through their app, and the chances of two people in the same household connecting from two mobile phones at once was slim to none.

CaptWoody · November 25, 2025, 5:55pm

Which mobile app are you using, 1 or 2?

MHedish · November 25, 2025, 6:50pm

I'm using the original app even though it says its 2.17.14. (White bird, green background).

I haven't seen the need to get the later one and set up yet another cloud account for stuff like this. I'll stick with the direct connection as long as I can.

CaptWoody · November 25, 2025, 7:11pm

Ok, that is what I figured. As I was standing in line at the store I realized that the new app is all cloud based including the password. There is no "controller password" like there is in the old app. So I am going to move back to the old app and see what happens.

Update - Well it turns out once you have updated the firmware it is no longer compatible with the old app with no way to downgrade. So I am back on the the new app.

MHedish · November 25, 2025, 8:54pm

Hmmmmm... No good that is.

While its possible they removed local passwords and want everyone going through the cloud <LouisRossmann>”So they can monetize our usage and/or start charging a subscription for things we've already bought and paid for!”</LouisRossmann>, it sure would've been nice to know upgrading the firmware obviates all local connections by removing the password.

Rachio has already started doing this.

Maybe... Delete the controller from the legacy app, reset the module, and start the connect process over again with the old app? (YMMV) My uneducated guess here is, the older app shouldn't care or even know there is a 4.x firmware, and it will set up a local password. On the other hand, they could have written something in to the older app via an update and it will force you to use the newer app to do the setup.

CaptWoody · November 25, 2025, 9:34pm

Unfortunately I did that and the old app does seem to care. Get a message saying that it is not compatible and have to use the new app. Pretty annoying.