iButton FAQ

All of the examples are provided with complete source code. The only exceptions to this are some 1-Wire Windows drivers that are released as binaries only. However, they can be distributed freely however.

All of the software examples are distributed under a ‘public domain’ style license located 
here . It is based almost word for word on the Xfree86 license. Developers are free to use and integrate the code into their applications without restriction.

Yes.

The mating plug is a Molex Part Number 22-04-1041. This is a PCB mounted connector.

No, the standard is a green LED. But the LED can be easily changed to another color.

No, only the customer that has set up the Custom ROM part has the right to buy it. This can act as a protective device to prevent reverse engineering or copying of a product

The only difference between the F3 and F5 is the height of the can. The F3 is 3.10mm and the F5 is 5.89mm. 
If humans are going to be interfacing with the iButton (picking it up), the F5 can is easier to handle.

The recalibration statement is a disclaimer. The sensor is exposed and it is possible for customers to use the DS1923 in a contaminated, dirty, polluted, etc environment. If that happened, the sensor would drift away from calibration due to contamination. Depending upon the environment, it might need recalibration after a short period. Since we have no control over this, we want to alert people that the accuracy could change.

The iButton is a slave device and requires a master to initiate communication to it. A master can be a PC or a micro processor. With the master constantly polling the iButtons, communication to iButtons can be started by a simple touch to a 1-Wire interface called a Blue Dot Receptor. Every iButton has a unique 64-bit serial number, which gives it a unique 1-Wire network address.

The iButton metal "can" is Type 305 Stainless Steel and the insulating grommet is molded from a polypropylene homopolymer resin that has a carbon black additive to inhibit breakdown due to ultraviolet light.

The iButton is ideal for any application where information needs to travel with a person or object. This includes point-of-sale transactions, remote access authorization, data logging (including time/temperature/humidity), maintenance and quality control. Because every iButton communicates a unique serial number, iButtons are always addressable and able to be located on a network.

Information is transferred between the iButton and host with a momentary contact.

Click here to see iButton Applications from around the world.

Thanks to sealed stainless steel, you can drop it, step on it, or scratch it. The iButton is wear-tested for 10-year durability and a million hot contacts.

Yes, the hardware used with the DS1921 can be used with all types of the DS1922 and DS1923.

The answer is to fill in the Temperature Alarm points. Even if the alarm is not turned on, the alarm points must have a value filled in.

The Temperature tab is used in the Forced Conversion mode. This cannot be done when there is a mission in progress. Go to the Mission tab and use the Temperature tab to see the data from the Thermochron.

Maxim does not recommend using the Thermochrons inside any living creature.

Enter the device name (i.e. DS2401) into the 'Part No. Search' text box of this web page (top right) and press enter. From the quick view page, click on the 'Technical Documents' tab. Scroll down to the reliability reports and open the PDF.

The ordering information on the web is correct for larger orders. Thermochrons have a small buffer stock that that is not reflected on the web and allows orders with less than 100 pieces to ship out quickly (usually less than a week).

Thermochrons can be missioned many times. The internal memory is overwritten when a new mission is setup. The device can be used until the internal battery is consumed. The battery is not rechargeable or replaceable.

The DS1920 is not a data logger, rather a temp sensor. The difference is a sensor requires a host PC or micro controller to interrogate the device for the temperature reading and stores the result in the host memory (Hard disk, etc.) and must therefore be connected to the device during the duration of the data collection. A data logger, once missioned (via PC software), does not require any other connections in order to take and store temperature readings. The data is stored in device's memory and extracted once the mission has completed.

Maxim no longer produces 1-Wire weather stations. For companies producing similar weather stations please see our Solutions Search.