Truebner FAQ

**There are instructions for the new cloud function (OTC) here**

General questions

What is OpenSprinkler?

OpenSprinkler is an open source, web based sprinkler/irrigation controller. It is a drop-in replacement for traditional sprinkler controllers that are not web connected. A web-connected controller like OpenSprinkler offers the following benefits:

  • Intuitive user interface (UI) : no more mess with buttons and knobs, no more running to your garage to make a single sprinkler program change. Instead, you use the web browser and mobile applications to set or change sprinkler programs. The web interface is much more intuitive than a small LCD screen.
  • Remote access : You can access your OpenSprinkler anywhere and anytime whether you are at home, in the office or traveling away (configuration required)
  • Smart control : OpenSprinkler can connect to the Internet and use real-time weather data (including historical and forecast data) to automatically make water time adjustments. Not only does it stop watering when it rains, but it also scales the water amount and time up and down based on your local outdoor temperature and humidity.
  • Connection options: We offer both controllers with built-in WiFi and controllers with integrated Ethernet port. In addition, the WiFi version can work without external routers, ideal for situations where you do not have an internet connection in the field.
Who is OpenSprinkler suitable for?

OpenSprinkler is suitable for homeowners as well as businesses, churches, farms, business parks and greenhouses. Typical applications include lawn and garden irrigation, plant watering, drip irrigation and hydroponics. It's cost-effective and expandable: OpenSprinkler can scale from 1-2 zones for a home up to 72 zones for a large company. With our app you can access multiple OpenSprinklers.

Also often used for

  • Lawn and plant watering system for hotels and hotel complexes
  • Football, tennis and sports fields (court irrigation), e.g. for sports clubs
  • Hardware stores with a horticultural market for the exhibition plants
  • Golf courses

Solenoid valves (e.g. 24VAC from Hunter, Rainbird and many more) are required for connection to the water pipes.

How many zones are supported?

By default, 8 zones are supported on the main controller. Each expander adds 16 zones. The latest firmware (2.1.9) supports a maximum of 72 zones.

What are the differences between the different hardware versions?

We currently offer OpenSprinkler 3.2 (with built-in WiFi), optionally with Ethernet connection and OpenSprinkler Pi (or OSPI, powered by a Raspberry Pi). In addition, the OpenSprinkler 3.2 is available in three different variants: AC powered, DC powered, and latch. AC power and DC power versions both work with standard 24V AC sprinkler valves. The main difference is that the AC version is powered by a 24V AC power supply and the DC version is powered by a low voltage 7.5V DC adapter. For International Customers: DC adapters are generally much easier to find than AC adapters. In addition, DC power version can work with any input voltage from 5V DC to 12V DC, including 12VDC solar panel. The latch control is also powered by a DC adapter, but only works with self-holding solenoid valves.

How many programs are supported?

The latest firmware (2.1.9) supports up to 35 programs on OpenSprinkler 3.0 and OSPI. Each program allows an individual watering time for each station (from 0 to 18 hours, accurate to the second) and two different appointment types:
1) Weekly Schedule, where you can select any combination of weekday (e.g. Monday and Wednesday);
2) Interval schedule where you can run the program every n days (n between 2 to 127) (e.g. every 3rd day).

Each program also allows two types of start times:
1) up to 4 fixed start times; or
2) Repeat start times (e.g. start at 8:30am, repeat every 45 minutes for 8 times).

The flexible start times can be combined for both cases, so you can set the watering many times a day with recurring intervals.

How is OpenSprinkler different from competitors?

Web-based sprinkler controllers are not a new idea. OpenSprinkler differs from similar products on the market in the following aspects:

  • OpenSprinkler has a built-in web interface and runs programs on its own processor. It does not rely on proprietary or PC-only software or cloud-only software. The web interface works with any modern browser. The HTTP API is well documented and allows local access without a cloud server. Our mobile app is free and supports all major platforms.
  • You can easily expand the number of zones up to 72. The costs are significantly cheaper than competing products on the market.
  • The software introduces an advanced set of features such as support for two independent master zones; Support for rain sensor, flow sensor, program start switch; Manual control using buttons, special station such as remote, radio frequency (RF), GPIO and HTTP stations. It offers flexible program start times, graphical preview of program schedules and log data, custom zone and program names, supports zones either sequentially or in parallel, watering time can be run accurate to 1 second. These features are rarely found in competing products.
  • We offer both the WiFi option and Ethernet jack option. In addition, we do not rely on cloud connections so that your controller works even when the internet is offline. The WiFi option also works in AP mode without an external router.
  • OpenSprinkler ships worldwide and supports more than 20 different languages.
  • OpenSprinkler is based on open source hardware and software. His design files are publicly available. If you are a technical developer, you can easily customize and extend its functionality in both software and hardware.
Where can I find the open source files?

All OpenSprinkler design files, schematic, board design, firmware code, app code including circuitry can be found on the OpenSprinkler Github repository page: https://github.com/OpenSprinkler .

Installation and use

What is in the package?

The package contains an OpenSprinkler controller (8 zones). You will still need a corresponding power adapter. For the AC version, the input voltage must be between 22V AC and 28V AC. The DC power version and latch version require a 7.5V DC (5-12V DC) power adapter. For the DC version, an international power adapter is included.

Does OpenSprinkler have an integrated network interface or only wireless?
  • OpenSprinkler 3.0 has only WiFi built-in (based on Esp8266 microcontroller), but no integrated Ethernet socket.
  • OpenSprinkler 2.3 has an Ethernet socket built-in, but no integrated WiFi.
  • OpenSprinkler Pi is powered by a Raspberry Pi, and the network options depend on your RPi.
  • OpenSprinkler 3.2 has WiFi and optionally a network adapter (ENC28J60 10MBit)
  • OpenSprinkler 3.3 has WiFi and optionally a network adapter (W5500 100MBit)
What kind of cable should I use?

Use a 'Fernmelde Erdkabel' for outdoor cabling, e.g. 'A-2YLY2 Diameter 0.8mm'. This is available from 4 to 20 Adrig.

FOR AC:

Type US AWG 20 AWG 18 AWG 16
Cable Diameter 0.8 mm 1.0 mm 1.3 mm
Cable Cross-Section 0.5 mm² 0.8 mm² 1.3 mm²
Max Length 200 m 300 m 450 m

FOR DC:

Type US AWG 20 AWG 18 AWG 16
Cable Diameter 0.8 mm 1.0 mm 1.3 mm
Cable Cross-Section 0.5 mm² 1 mm² 1.3 mm²
Max Length 100 m 150m 200m

FOR LATCH:

Cable Cross-Section 1 mm²
Max Length 30 m

Thicker cables allow longer cable lengths. Applies to standard valves with approximately 300 mA switching current and

  1. at AC a 24VAC power supply with >= 36VA power (at 24VAC max 1.5A)
  2. at DC and Latch a DC power supply >= 20W (at 7.5V-12V, approximately 2.7A)

The cable of the magnetic valves must be connected to this cable, e.g. with “3M Scotchlok 314”

With what kind of magnetic valves can we work?
  • AC operated OpenSprinkler (including OSPI) works with standard – 24VAC sprinkler valve controllers. It is compatible with existing 24VAC – systems, including pump start relays, wireless sensors, which require 24VAC power. 24VAC valves open when powered and close when powered off.
  • DC operated OpenSprinkler works with both 24V AC sprinkler valve controllers and 12 VDC (non-self-holding) valves. It comes with a power adapter for 2A, sufficient for 4 valves. However, for certain 24VAC pump start relays and wireless sensors, which require a lot of 24VAC power, you may need to provide a separate 24VAC power supply. 24VAC or 12VDC valves open when powered and close when powered off.
  • Latch OpenSprinkler only works with DC Magnetrast Ventiles. These are self-holding valves, which require an impulse for each state change.
I'm new to sprinkler systems. How can I install OpenSprinkler with existing magnetic valves?

OpenSprinkler is designed to be a drop-in replacement for your traditional sprinkler controllers. Whether you're installing a new system or replacing an existing controller, DIY installation is easy and can be completed quickly:

No , the control is not water-tight and should not be used outdoors without protection. For outdoor installations, you should use a What sensors does OpenSprinkler support?

OpenSprinkler currently has two sensor ports, which can be used to read a rain sensor, a soil moisture sensor, a flow sensor, or a program start button. Any rain sensor or soil moisture sensor that works like an open or close contact will be supported. Standard dry contact flow sensors (two-wire type) are supported, but some three-wire types (with external 5V supply) are also supported. Water meters with pulse outputs are also supported. You can also connect a switch/button to the sensor port and start a program by pressing the button. The firmware allows you to configure the sensor type and choose the sensor parameters.

Does OpenSprinkler support a soil moisture sensor?Yes, a digital soil moisture sensor is supported from firmware version 2.1.9. Digital means it can represent the soil moisture as a yes/no signal. For the OpenSprinkler, we have the New is the additional product “Analog Sensor Board”, which has 8 analog inputs and allows the connection of up to 8 analog sensors, such as the SMT50. Does OpenSprinkler support Master-Zone or pump stations?

Yes. OpenSprinkler uses software-defined Master-Zone / Pump stations, and supports up to 2 independent Master / Pump zones. Each of the available connections can be configured as a Master / Pump zone.

Can I insert two wires into the same Zone Port?

Yes. But remember that, if you do this, the two zones will always be opened and closed together.

Can I run multiple zones at the same time? Yes. OpenSprinkler firmware allows you to run each zone in ‚parallel‘ mode by disabling the ‚sequentially‘ flag. A parallel zone can be run at the same time as other zones. Can I use OpenSprinkler to control devices other than solenoid valves? Yes. OpenSprinkler firmware has built-in support for GPIO (all-purpose) IO stations, HTTP stations, and RF transmitters. This allows you to directly switch an alternative GPIO, send a general HTTP GET command, or control RF remote switches, which in turn control all powerline devices, such as landscape lights, Christmas lights, pumps, heaters, and fans. Details can be found in our What is the LCD and the buttons for?

OpenSprinkler has an integrated LCD display that shows the current time, zone status, and rain status. The buttons are used to display the IP address or perform a factory reset.

How do I check the IP address that OpenSprinkler has been assigned?

Press the B1 button, and the IP address will be displayed on the LCD display.

How do I program a program button manually?

Hold the B3 button until a program start message appears. Then follow the instructions on the LCD display.

What happens in case of a power outage?

OpenSprinkler stores all programs and settings in a non-volatile memory. So the data remains even in case of a power outage.

Web connections

How do I access OpenSprinkler?

OpenSprinkler has an integrated web interface that works with most desktop and mobile web browsers. Simply open a browser and enter the IP address of the controller in the address bar. We also offer a free OpenSprinkler mobile app. Search for ‘OpenSprinkler’ in your app store. The mobile app can automatically scan the local network and identify the IP address of OpenSprinkler. In contrast to some other web-based controllers, OpenSprinkler DOES NOT require a cloud connection – your data remains local on the controller. You can access it locally without going online. Can OpenSprinkler run offline without an internet connection? In contrast to some other web-based controllers, OpenSprinkler DOES NOT require a cloud connection – your data remains local on the controller. You can access it locally without going online. .

Yes. Once programmed, OpenSprinkler can run completely offline without a network connection. The controller has an integrated real-time clock and battery for time measurement. You can also manually start an existing or test program on the controller using the buttons.

Can I also use OpenSprinkler without a WiFi router?

With the latest firmware (2.1.8), OpenSprinkler 3.0 supports all functions in AP mode – it can act as a wireless LAN hotspot, so that mobile phones and laptops can connect to it and access OpenSprinkler.

How do I access OpenSprinkler remotely?

You can access OpenSprinkler remotely using the

Hold the B3 button until you see a program message. Then follow the instructions on the LCD screen.

What happens if there is a power loss?

OpenSprinkler stores all programs and settings in non-volatile memory. This means the data is retained even in the event of a power failure.

Web connections

How do I access OpenSprinkler?

OpenSprinkler has a built-in web interface that works with most desktop and mobile web browsers. Simply open a browser and enter the controller's IP address in the address bar. We also offer a free OpenSprinkler mobile app. OpenSprinkler mobile app, search for ‘OpenSprinkler’ in your app store. The mobile app can automatically scan the local network and detect OpenSprinkler's IP

Unlike some other web-based controllers, OpenSprinkler does NOT require a cloud connection – your data remains local to the controller. You can access on site without going through the Internet.

Can OpenSprinkler run offline without an internet connection?

Yes. Once programmed, OpenSprinkler can be run offline without a network connection at all. The controller has an integrated real-time clock and battery for time measurement. You can also manually start an existing or test program on the controller using the buttons.

Can I use OpenSprinkler without a WiFi router?

With the latest firmware (2.1.8), OpenSprinkler 3.0, all features are supported in AP mode — it can serve as a wireless LAN hotspot itself, allowing mobile phones and laptops to connect to it and access OpenSprinkler.

How do I access OpenSprinkler remotely?

You can access OpenSprinkler Remote by using Port – Forwarding To do this, you need to access your router's configuration page and create an entry in the Port Forwarding or Port Mapping section that points to the OpenSprinkler IP address and port.

For a Fritz!Box, you can find this under 'Internet / Port Mapping / Port Forwarding'. There, create a port forward for the OpenSprinkler IP and port. In the next step, under 'Internet / Port Mapping / Fritz!Box Services', enable the 'Internet access to the FRITZ!Box over HTTPS' option or create a corresponding address under 'Internet / Port Mapping / DynDNS'. Under the specified address under 'Internet address of your FRITZ!Box', your OpenSprinkler will also be available.

Important note: With some UnityMedia connections, only an IPv6 address is assigned, and the IPv4 address is shared by multiple connections. Unfortunately, this makes it impossible to activate port forwarding. However, it still works via Wi-Fi.

NEW: Register an OTC (OpenThings Cloud) token, enter the token in your OpenSprinkler, and access it from anywhere. Learn more about this topic here.

Will push notifications be supported?

Starting from firmware version 2.1.7, OpenSprinkler supports push notifications via IFTTT, which can be configured to send notifications via SMS, email, or app notifications. Please check for further details. If I have multiple OpenSprinklers, can they communicate with each other?

Our firmware supports Remote Controller – a feature that allows an OpenSprinkler to function as a master controller, sending commands to one or more remote controllers to open or close their valves.

This is useful if you have a large property with separate groups of valves. What is the maximum distance between the controller and valves?

This depends on the wire gauge (AWG) you use to connect the valves. In general, you can run up to 200m with 20 AWG wires, 300m with 18 AWG wires, and 450m with 16 AWG wires. Thicker wires allow longer distances.

What is the maximum allowed distance between the main controller and the expansion board?

This also depends on the wire gauge (AWG) of the extension cable. The standard cable with expansion boards delivered is a 24 AWG 15-inch long cable. You can increase this length using a custom cable with thicker wires.

Can I connect the sprinkler system's magnetic valves to garden hoses?

Yes, you will probably need an adapter, which you can get online or at a hardware store.

How do I update the firmware?

OpenSprinkler 3.0 supports firmware update over-the-air (OTA) via Wi-Fi. OpenSprinkler 2.3 requires a USB cable and a computer to update the firmware. OpenSprinkler Pi supports network or script-based firmware updates. Please check the

page for instructions. How can I use a static IP address? The recommended method is to assign the IP address through your router.

Alternatively, you can disable the OpenSprinkler DHCP option and enter a static IP address. Note that you must set the router IP correctly for all functions to work properly.

How do I reset the settings to the default values?

Turn off OpenSprinkler, then turn it back on. If the OpenSprinkler logo appears, immediately hold down the first button B1 until the message 'Reset All' appears? If you're sure, then press and hold the third button B3 until the controller restarts. OpenSprinkler is then back to its default settings.

How does the weather-based adjustment of irrigation work?

The weather-based adjustment uses your location and queries OpenWeatherMap to obtain real-time weather data. It then calculates a value that applies the irrigation percentage to all water stations. The percentage value is calculated based on local temperature, humidity, and precipitation (rainfall) and varies from 0% to 250%. The value is updated every hour. For example, low temperatures, high humidity, and/or significant rainfall result in reduced or no irrigation, i.e., 0%. On the other hand, high temperatures and dryness result in increased irrigation time. In very hot temperatures, this can even reach 200%.

How can I help OpenSprinkler support more languages?

In OpenSprinkler, the localized language is a crowd-sourced function, so everyone can help. Go to the web interface -> sidebar -> about page and click on the link to localization.

Can I integrate my own app or use custom scripts that access the OpenSprinkler interface?

Absolutely. Please note the support page for API documentation.

Technical questions

What is the difference between the various versions of OpenSprinkler?

is a completely assembled commercial product that works out of the box. It comes with buttons and a display.

OpenSprinkler Pi (Ospi)

Truebner is a sprinkler expansion board for RPi – it uses RPi as the main processor. Users expect some experience with RPi to set up software. Please check the specific product web pages for further details.

OpenSprinkler 3.0 AC / DC / Latch Compatibility

AC / DC / OSPI all work with 24VAC sprinkler magnets. OSDC also supports OpenSprinkler 3.0 AC / DC / Latch
12V non-latching DC valves. Latch version only supports DC impulse coils. Power supply OS AC and OSPI require a 24 V AC power adapter (not included by default) 12V non-holding DC valves. Latch version only supports DC pulse coils.
Power supply OS AC and OSPI requires 24V AC power supply (not included as standard)
OS DC and Latch are versatile: 5V ~ 12VDC (e.g. 5V USB, 12V solar panel). A 7.5VDC adapter is included in the delivery.
Number of stations 8 (expandable to 72) 8 (expandable to 72)
App Yes Yes
Weather Integration Yes Yes
Logging-Support Yes Yes
Processor Esp8266 Suitable for RPi 1 Model A + / B + or RPi 0, 2 and 3
Is assembly required? Fully assembled Requires RPi insertion and software setup
LCD Yes (O 2.3: 16 × 2 characters; O 3,0: 128 × 64 OLED) None
Ethernet port OS 3.0: no
OS 3.2: yes		 Yes (except RPi 1 A +)
Built-in Wi-Fi Yes Yes, if your RPi has WiFi (e.g. via USB)
Firmware Uniform OS Firmware Uniform OS Firmware
Firmware Upgrade Over-the-Air (OTA) via network
Target group Everyone RPi Enthusiasts
Package includes OS – Controller, Reel connectors,
with enclosure		 Ospi Addon-Board to be inserted, with reel connectors, with enclosure. RPi not included.
Enclosure Yes, cast Yes, laser-cut Acrylic
Optional Add-ons OS3AC: 24 V AC-Adapter
Zone Expander +16 zones		 24 V AC-Adapter
Zone Expander +16 zones