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HobbyBoards EE/EF Microprocessor-based slaves
Ultra Violet (UV) Index sensor
Soil and Leaf moisture measurements
4-channel hub with switchable branches


General EE device

EE [.]XXXXXXXXXXXX[XX][/[ temperature | version | type_number | temperature_offset | address | crc8 | id | locator | r_address | r_id | r_locator | type ]]

UVI sensor

EE [.]XXXXXXXXXXXX[XX][/[ UVI/UVI | UVI/UVI_offset | UVI/in_case | UVI/valid | temperature | version | type_number | temperature_offset ]]

General EF device

EF [.]XXXXXXXXXXXX[XX][/[ version | type_number | address | crc8 | id | locator | r_address | r_id | r_locator | type ]]

Moisture Meter

moisture/is_moisture.[0-3|ALL|BYTE] | moisture/is_leaf.[0-3|ALL|BYTE]
moisture/calibrate/min | moisture/calibrate/max | moisture/calibrate/raw.[0-4|ALL]


hub/branch.[0-3|ALL|BYTE] | hub/short.[0-3|ALL|BYTE]

Family Code

Device with temperature
Device without temperature
Moisture Meter

Temperature Properties


read-only, floating point
Temperature read every 30 seconds. Resolution .5C (uses an on-board DS18B20). Temperature is only present in the EE-series devices.


read-write, floating point
Offset stored on device to apply to temperature readings.

Uvi Properties


read-only floating point
UV Index (ultraviolet index) in the range 0.0 to 16.0 resolution .1

Only the UVI version of the EE device has a UVI sensor. Readings made every .5 seconds.


read-write, floating point
Signed offset to apply to the UVI measurement. Stored on-device non-volatile.


read-write, yes-no
Flag to apply compensation for the protective case. Stored on-device non-volatile.


read-only, yes-no Flag the the EE device type matches the known UVI type.

Moisture Meter

moisture/sensor.0 .. moisture/sensor.3 moisture/sensor.ALL

read-only integer
Up to 4 sensors reading moisture can be attached. OWFS addresses the sensors as 0 through 3 while the datasheet uses 1-4. Two types of external sensors are supported (and the data range):
Watermark Soil Moisture Sensor
Leaf Wetness Sensor

moisture/is_moisture.0 .. moisture/is_moisture.3 moisture/is_moisture.ALL

moisture/is_leaf.0 .. moisture/is_leaf.3 moisture/is_leaf.ALL

read-write yes_no
Set or get the type of sensor attached to each channel. Note that OWFS addresses the sensors as 0 through 3 while the datasheet uses 1-4. Two types of external sensors are supported:
Watermark Soil Moisture
Leaf Wetness

Note that is_leaf and is_moisture are complementary and clearing one sets the other.



read-write unsigned integer
Set or get the upper and lower range for the raw data for leaf wetness scaling. See the datasheet for details.

moisture/calibrate/raw.0 .. moisture/calibrate/raw.3 moisture/calibrate/raw.ALL

read-only unsigned integer
Read the raw leaf wetness values for setting scaling. See the datasheet for details. Note that OWFS addresses the sensors as 0 through 3 while the datasheet uses 1-4.


4-channel hub. Individual branches can be switched on and off.

hub/branch.0 .. hub/branch.3 hub/branch.ALL hub/branch.BYTE

read-write, yes-no
The HobbyBoards hub has four 1-wire bus lines. Each branch is electricaly isolated from reflections and shorts, and can be optionally excluded from the 1-wire network.

You can turn each branch on or off by writing 0 (off) or 1 (on) to the corresponding property. Note that OWFS indexes the branches 0 to 3 while the datasheet uses 1 to 4.

The easiest way to turn all the branches on is to write 15 (0x0F) to hub/branch.BYTE

hub/short.0 .. hub/short.3 hub/short.ALL hub/short.BYTE

read-only, yes-no
Is the corresponding branch in "short" condition? (Electrically shorted out).

Identification Properties


read-only, ascii
Firmware version for the EE/EF device. Reported in HH.HH format where HH is a hex digit (0-9A-F).


read-only, integer
Index of the type of sensor built into this device. Current known assignments:
  1. UVI (Ultraviolet index)
  2. Moisture meter
  3. Moisture meter with datalogger
  4. Sniffer
  5. Hub

Standard Properties



read-only, ascii
The entire 64-bit unique ID. Given as upper case hexidecimal digits (0-9A-F).
address starts with the family code
r address is the address in reverse order, which is often used in other applications and labeling.


read-only, ascii
The 8-bit error correction portion. Uses cyclic redundancy check. Computed from the preceding 56 bits of the unique ID number. Given as upper case hexidecimal digits (0-9A-F).


read-only, ascii
The 8-bit family code. Unique to each type of device. Given as upper case hexidecimal digits (0-9A-F).



read-only, ascii
The 48-bit middle portion of the unique ID number. Does not include the family code or CRC. Given as upper case hexidecimal digits (0-9A-F).
r id is the id in reverse order, which is often used in other applications and labeling.



read-only, ascii
Uses an extension of the 1-wire design from iButtonLink company that associated 1-wire physical connections with a unique 1-wire code. If the connection is behind a Link Locator the locator will show a unique 8-byte number (16 character hexidecimal) starting with family code FE.
If no Link Locator is between the device and the master, the locator field will be all FF.
r locator is the locator in reverse order.

present (DEPRECATED)

read-only, yes-no
Is the device currently present on the 1-wire bus?


read-only, ascii
Part name assigned by Dallas Semi. E.g. DS2401 Alternative packaging (iButton vs chip) will not be distiguished.





1-wire is a wiring protocol and series of devices designed and manufactured by Dallas Semiconductor, Inc. The bus is a low-power low-speed low-connector scheme where the data line can also provide power.

Each device is uniquely and unalterably numbered during manufacture. There are a wide variety of devices, including memory, sensors (humidity, temperature, voltage, contact, current), switches, timers and data loggers. More complex devices (like thermocouple sensors) can be built with these basic devices. There are also 1-wire devices that have encryption included.

The 1-wire scheme uses a single bus master and multiple slaves on the same wire. The bus master initiates all communication. The slaves can be individually discovered and addressed using their unique ID.

Bus masters come in a variety of configurations including serial, parallel, i2c, network or USB adapters.

OWFS design

OWFS is a suite of programs that designed to make the 1-wire bus and its devices easily accessible. The underlying priciple is to create a virtual filesystem, with the unique ID being the directory, and the individual properties of the device are represented as simple files that can be read and written.

Details of the individual slave or master design are hidden behind a consistent interface. The goal is to provide an easy set of tools for a software designer to create monitoring or control applications. There are some performance enhancements in the implementation, including data caching, parallel access to bus masters, and aggregation of device communication. Still the fundemental goal has been ease of use, flexibility and correctness rather than speed.

Ee / Ef

The EEEF (3) are a reference platform of microprocessor based 1-wire slaves. In general they require external power, and have an on-board index for the specific capabilities. They are designed by Eric Vickery at

The EE class device uses family code EE and has an included temperature sensor. The EF devices have no temperature sensor,


The UVI sensor is an implementation of the EE class device with Ultra Violet Index sensing. All it’s specific properties are in the UVI/ directory.


All 1-wire devices are factory assigned a unique 64-bit address. This address is of the form:
Family Code
8 bits
48 bits
8 bits

Addressing under OWFS is in hexidecimal, of form:

where 01 is an example 8-bit family code, and 12345678ABC is an example 48 bit address.

The dot is optional, and the CRC code can included. If included, it must be correct.


Moisture and Leaf Sensor
4 Channel Hub

See Also


owfs (1) owhttpd (1) owftpd (1) owserver (1) owdir (1) owread (1) owwrite (1) owpresent (1) owtap (1)

Configuration and testing

owfs (5) owtap (1) owmon (1)

Language bindings

owtcl (3) owperl (3) owcapi (3)


DS1427 (3) DS1904(3) DS1994 (3) DS2404 (3) DS2404S (3) DS2415 (3) DS2417 (3)


DS2401 (3) DS2411 (3) DS1990A (3)


DS1982 (3) DS1985 (3) DS1986 (3) DS1991 (3) DS1992 (3) DS1993 (3) DS1995 (3) DS1996 (3) DS2430A (3) DS2431 (3) DS2433 (3) DS2502 (3) DS2506 (3) DS28E04 (3) DS28EC20 (3)


DS2405 (3) DS2406 (3) DS2408 (3) DS2409 (3) DS2413 (3) DS28EA00 (3)


DS1822 (3) DS1825 (3) DS1820 (3) DS18B20 (3) DS18S20 (3) DS1920 (3) DS1921 (3) DS1821 (3) DS28EA00 (3) DS28E04 (3) EDS0064 (3) EDS0065 (3) EDS0066 (3) EDS0067 (3) EDS0068 (3) EDS0071 (3) EDS0072 (3) MAX31826 (3)


DS1922 (3) DS2438 (3) EDS0065 (3) EDS0068 (3)


DS2450 (3)


DS2890 (3)

Multifunction (current, voltage, temperature)

DS2436 (3) DS2437 (3) DS2438 (3) DS2751 (3) DS2755 (3) DS2756 (3) DS2760 (3) DS2770 (3) DS2780 (3) DS2781 (3) DS2788 (3) DS2784 (3)


DS2423 (3)

LCD Screen

LCD (3) DS2408 (3)


DS1977 (3)


DS2406 (3) TAI8570 EDS0066 (3) EDS0068 (3)


EEEF (3) DS2438 (3)



Paul Alfille (

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