Last Updated June 26, 2015
NOTE: TEMP05 ceased production on June 30, 2003. It has been replaced by the TEMP08.
Need other information? Try the HomeSeer TEMP05 forum here.
Parasitic Power is a term developed by Dallas Semiconductor to describe their method of powering their "1-Wire" devices. The DS18S20 sensor used by the TEMP05 is one of these 1-Wire devices. As the term implies, there is only one wire (well, 2 really. A ground is also required) used to communicate on a bus with all devices. The power is derived from the communication line. Whenever a logic "1" is sent on the 1-Wire bus, all devices on the bus use that logic "1" to charge up their internal circuitry. Providing that a logic "1" is sent often enough, that charge is sufficient to drive the individual devices. Fortunately, the idle state of the bus is a logic 1, so, statistically, a logic 1 is present very often.
No. TEMP05 can be used with any combination of the following devices on the 1-Wire bus;
The sensors are connected via twisted pair wire, typically CAT-5 or better, to connector J2. The external wire can be "home run" (all sensors connected on their own wire and all end-points tied together), or daisy-chained (one, or more, wire runs are used and each sensor is "tapped" into the wire run where needed). The sensors themselves are then soldered on to the wire run wherever they are needed. If you don't like soldering these devices, some people have had success with crimping the sensors into RJ-11 plugs and running wires to RJ-11 sockets where the sensors are needed. Midon Design also provides small PCB mounts for attaching a DS18S20 sensor and either a RJ-11 connector or 2 terminal screw connector. They are shown here.
NOTE: if you are using parasitic power, you must connect the ground wire to both outer pins of the DS18S20 to ensure reliable readings.
Yes. They can be wired into anywhere along the wire run from TEMP05. A termination is not required at the end of the wire run when daisy-chaining, although care should be taken to avoid shorting out the end point.
Using good quality CAT-5 cable, you should be able to run sensors up to 300 feet (100 meters) away from the TEMP05.
The original manufacturer (Dallas Semiconductor) no longer makes this product. One manufacturer Tecnologia Aplicada (AAG) has replicated the original design (see also question 19). Another source of similar product is Texas Weather Instruments Inc. . Midon Design has verified functionality of Technoligia Aplicada and Dallas Semiconductors products with the TEMP05.
A straight-through, not null modem, serial cable connects between the TEMP05 and your PC's serial port. The signal is 9600 bps, no parity, eight bits, with NO flow control. Hyperterminal can be used to monitor output from the TEMP05, or to configure it. See also #17. Here is an example of a serial cable that could be used to connect to your PC.
Yes, although care must be taken to ensure that the connections to the sensor, and the sensor leads, are properly water-proofed. Silicon RTV or epoxy could be used to accomplish this.
The recommended method is to connect one sensor at a time, run the INI command on TEMP05 and then record the newest serial number found in the list displayed by the DIS command. That serial number will appear in the sensor output if the SID ON command has been issued.
Alternatively, all sensors can be pre-configured. Attach each sensor one at a time. Note which sensor output value changes from "???" to a valid temperature reading after attaching a new one. That is your new sensor.
If you have already installed all your sensors, just disconnect each one individually and look for the sensor that changes value from a valid temperature reading to "???".
With Version 5 and higher software, TEMP05 will notify you real time as you connect and disconnect temperature sensors, providing that the sensor had initially been registered with TEMP05 via the INI command.
Just about any power adapter can be used with the TEMP05. If your are NOT using the companion RELAY05 module, then you can look through your discarded wall adapters from old electronic devices for something that is rated at least 9 Volts (AC or DC) and at least 100mA (milli-Amperes). If you are using RELAY05 with TEMP05, then your adapter needs to be between 12 and 15 Volts with at least 800mA current capability.
For example, to get temperature readings from 3 different areas you will
A sample HomeSeer script is available from the TEMP05
No. Any PC application that reads the serial port can be used. HomeSeer provides some simple to use script and plug-in interfaces to the serial port, however.
Yes. TEMP05 has been successfully tested with a Belkin F5U103 USB Serial Adapter.
Yes! V4.14 firmware and higher will read humidity from multiple DS2438 Humidity sensors from Midon Design, AAG or Hobby Boards.
The document here describes this best. Basically, the DS18S20 has superior temperature accuracy and a wider power supply tolerance.
Correct settings in HyperTerminal are:
Follow the instructions here.
The Version 1 OWWS is the original unit developed and sold by Dallas Semiconductor. Is is electrically equivalent to the Version 2 OWWS sold by AAG, a Mexican company. AAG improved the design to replace the DS2401-based wind direction sensors with a new DS2450-based design and are now selling it as the Version 3 OWWS. TEMP05 firmware V4 will work with the Version 3 or Version 1 or Version 2 OWWS. TEMP05 V5.00 and higher firmware no longer supports the Version 1 OWWS, however.
Dallas/Maxim have chosen not to label the DS18S20's with the "S". This may be due to the fact that they have discontinued the original DS1820 package and assumed that there would be no confusion. The DS1820 stopped production around May 2000. The only visible difference is the package style. The DS1820 was in a PR-35 package, whereas the DS18S20 is in a standard TO-92 package. See FAQ #16 for the electrical differences.
Absolutely! You will need V4.21 or higher software to read the DS18B20 and DS1822 sensors. DS1920 sensors are identical to DS1820 sensors and can be read with any version of TEMP05.
The ??? is used to display incorrect readings. While there are several possibilities for this, faulty sensors for example, there is one likelier problem with 4.19 or higher software. The NOR command, which is used to calibrate the wind direction sensor(s), stores the calibration results in one of your DS1820 sensor's EEPROM memory. If you have removed the DS1820 sensor that had that information stored, or did an ERA and INI command, then the software will read incorrect calibration results and error out on the direction. Try re-doing the NOR command and see if that helps.
This problem is not evident with V5 software.
You might have added a the sensor via a new wire leg in a star configuration. This might have created reflections on the One Wire bus. Try adding a 100 ohm resistor (Radio Shack part number 271-1311) in series with each leg of the star (only on the DQ lead). The figure below shows how the wiring should be done for this.
Midon Design sells a 1 Wire Humidity Sensor as part number MD3020E. They were originally available from Dallas/Maxim, however, Dallas/Maxim announced the discontinuation of this product. An alternate source is Hobby Boards. Go to this link to view the Midon Design version. AAG also sells a humidity sensor, however, it is only available in parasitic power mode.
Exposure to direct sunlight can affect the sensors - they read too high. A solution for this is to put the sensors in a "pagoda". Construction articles are shown on the following links:
More discussion here: HomeSeer TEMP05 Messages
From a HyperTerminal session, issue an INI command. This will find the new sensor and add it's serial number to EEPROM memory. There is no need to do an ERA command, which will erase all the EEPROM memory, unless you want to delete some or all of the other sensors that were previously recognized. The new sensor(s) added by the INI command are automatically added to the next available (usually the last) memory position.
No. We have looked into using the SHT (Sensirion) sensor series but decided that the 2 wire interface used to connect to it was not conducive to remote applications like the One Wire bus is used for.
Please see an excellent discussion about this on the HomeSeer message board here.
The following schematic is good for any of the DS2405, DS2406 or DS2407 1-wire devices. As can be seen, the PIO port can be used for switch (or contact closure) inputs, or as an output to drive LED's, relays, or other devices.
Here is a table of all published connector schemes for various 1-wire devices:
The pin numbers are numbered per the diagram here.
Download the PDF version of this table here.
There are 2 ways of doing this. If you are using Ken Mitchell's TEMP05 plug-in, activate relays from the HomeSeer web page, or GUI, simply by pressing one of the relay On/Off buttons. This can also be accomplished via a script by using the following command:
hs.execx10 "[x","on",0 where x is the relay number and [ is the relay house code
If you are not using the TEMP05 plug-in, then use a script with the following command to activate a relay:
hs.SendToComPort 1,"rlyxon" where x is the relay number
Last Updated February 21, 2018
P.O. Box 1929
Suwanee, GA 30024 USA
Please report any problems with this site to