The iButton is a small, durable electronic device from Dallas Semiconductor, that has a unique identification number and a microchip inside a water-resistant, stainless steel container. It is used for various applications such as access control, asset management, and data storage. These devices are typically mounted on a key fob or other objects and can be read by special reader devices that establish contact with the iButton’s chip through its protective casing.


The phonetic pronunciation of “iButton” is: aɪ-bʌt-n

Key Takeaways

  1. iButton is a small, durable, and versatile data carrier that combines the functionality of a microchip and data storage in a robust stainless-steel casing.
  2. It has various applications including access control, identification, temperature and humidity monitoring, and asset tracking.
  3. iButton devices can easily be read and written using a simple, low-cost interface, making them a cost-effective and efficient solution for data storage and transfer.


The technology term “iButton” is important because it represents a unique, coin-sized computer chip encapsulated in a stainless steel container, providing a reliable, rugged, and portable data storage and authentication solution.

Produced by Maxim Integrated Products, iButtons serve for various practical applications, such as secure access control, asset tracking, electronic cash transactions, and data logging.

With their compact design and ability to withstand harsh environmental conditions, iButtons offer a cost-effective and versatile alternative to traditional smart cards and tokens, enabling seamless integration into numerous systems across multiple industries.

Thus, their significance lies in promoting efficiency, security, and ease of use in the ever-evolving world of technology.


iButton is an innovative device designed to serve various purposes, most notably in the areas of security, identification, and data storage. Its compact nature and durability make it an attractive option for individuals and businesses alike. The primary purpose of an iButton is to streamline the process of authentication and provide a reliable means of secure access. In essence, it operates as a digital key, granting users access to sensitive information or restricted areas.

Additionally, these devices are commonly employed for time and attendance tracking, ensuring an efficient system for monitoring the check-ins and check-outs of employees in an organization. They can also store valuable information, enabling quick access to it whenever necessary. The iButton’s unique structure contributes significantly to its versatility. Encased in a stainless steel shell for protection, it is resilient to harsh conditions, making it suitable for use in environments where conventional electronic devices may struggle.

This robustness extends to its ability to withstand extreme temperatures, harsh chemicals, and physical impacts. Furthermore, iButtons support serial communication, allowing for easy integration with existing networks, making them ideal for streamlining your security and identification systems. With an expansive range of models on the market, users can find the perfect iButton device to cater to their specific needs, from mere storage capabilities to advanced cryptographic features for heightened security measures. Overall, the iButton presents a compact and reliable solution to an array of technological demands.

Examples of iButton

Access Control Systems: iButtons have been widely used in security and access control systems for buildings and offices. Users carry a uniquely coded iButton device, which is read by a probe or reader installed at the entrance of the restricted area. When the iButton touches the reader, its unique code is transmitted, granting or denying access based on whether the user has the necessary permissions.

Time and Attendance Management: In businesses that employ hourly workers, iButtons can be used as electronic timesheets. Employees carry their personal iButtons and tap them against a reader when they start and end their work shift. This information is logged into a database, allowing employers to accurately track the number of hours worked and calculate employee pay.

Electronic Payment Systems: iButtons have been implemented in electronic payment systems, particularly in public transportation and retail outlets. Users can load funds onto their iButton devices and make payments by tapping them on a reader at the point of sale. This contactless payment method provides a convenient and secure alternative to traditional cash or credit card payments. Examples of such systems include Dallas Semiconductor’s “CyberCash” project and the Moscow Metro’s electronic ticketing system.

iButton FAQ

What is an iButton?

An iButton is a small, coin-sized device that contains a built-in processor, memory or other specialized components. It is used for a variety of applications, such as access control, data logging, and identification purposes.

How does an iButton work?

iButton devices work by transferring data via a simple touch or “momentary contact.” They communicate through a 1-Wire communication protocol and operate over a wide range of temperatures, making them suitable for various environments.

What are some common uses for iButtons?

iButtons are commonly used for electronic locks and keys, asset tracking, inventory management, time and attendance tracking, electronic cash transactions, and temperature or humidity data logging.

Are iButtons durable and reliable?

Yes, iButtons are designed for use in harsh environments. They are made from stainless steel and are water-resistant, rust-resistant, and durable. Their simple contact structure makes them highly reliable for data transfer and storage.

How is the data stored in an iButton?

iButton devices store data in their built-in non-volatile memory. The data remains stable even when the iButton is not connected to a power source and can be retained for as long as 10 years in some models.

How do you read and write data from an iButton?

To read or write data from an iButton, it must be connected to a host system using a reader or adapter that supports the 1-Wire communication protocol. The host system can be a computer or a microcontroller, and it uses specific software or firmware to interface with the iButton.

Related Technology Terms

  • 1-Wire Protocol
  • Data Logger
  • Electronic Key
  • DS1990A Serial Number
  • Thermochron

Sources for More Information


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