IButton is a computer chip encapsulated in a 16mm thick stainless steel housing. Because of its unique robust housing, the latest information can be carried anywhere with the person or the target object. In fact, the steel iButton housing is solid enough to withstand various harsh indoor or outdoor environments, making it almost accessible to install anywhere. IButton is very small and lightweight and can be attached to key chains, ring rings, watches, or other personal items, it is ideal for controlling access permissions for buildings and computers, asset management, and various data records in daily life. IButton Composition 1. the housing and metal buckle iButton use the stainless steel 'housing 'as the electronic communication interface, each housing has a data contact, called the "lid", and a grounding contact, called the "bottom ". These contacts are connected to an internal silicon wafer. The lid is the top of the shell, and the bottom is composed of the edge and bottom of the shell, including a flange that facilitates the button to attach to any other object. The two contacts are isolated by polypropylene snap rings. 2. The 1-wire interface can communicate with iButton through the 1-wire protocol only by tapping iButton with the above two interfaces. The 1-wire interface has two communication rates: 16 kbps in standard mode and 142 Kbps in overdrive mode. 3. address each chip in the iButton housing has a unique address engraved by a laser and cannot be changed. This address (such as 2700000095c33108) can be used as the serial number or identifier of each iButton. At present, the iButton product line contains more than 20 products, providing various functions for basic buttons. IButton provides the following types: 1. Only address 2. Memory 3. Real-time clock 4. Security 5. How does the data recorder read and write iButton information? Information Transmission Between iButton and PC is achieved through Transient Contact, and the transmission speed is as high as 142 kbps. You only need to use iButton to tap the blue dot receiver or other iButton detectors connected to the PC. Connect the blue dot receiver to the 1-wire adapter on the idle port of the PC using a cable. The existing 1-wire adapter supports USB ports, serial ports, and parallel ports. The blue dot receiver and 1-wire adapter are inexpensive. IButton is also the final information carrier of autoid and a variety of portable applications. All the latest handheld computers and PDAs can communicate with iButton. For a complete list of portable devices that can communicate with iButton, visit iButton solutions search. What is the durability of iButton? The silicon wafer in iButton is protected by durable material-stainless steel to the maximum extent. You can put it on the ground, step on your feet, or scratch it at will. IButton has been worn out for 10 years. What can iButton do? IButton is ideal for any application that requires information to be carried with you or as you go. IButton can be attached to a key chain, watch, or ring to authorize its owner to enter a building and use computers, instruments, and transportation equipment. IButton can be attached to the toolkit to measure the entire process, such as manufacturing, product delivery, and maintenance, to improve work efficiency. Some iButton versions can store electronic cash in small transactions, such as transportation systems, parking fees, and vending machines. IButton can also be used as an electronic asset tag to store information required to track assets of valuable devices. What do I need to do to implement the iButton application? Any iButton application consists of the following four basic parts. 1. iButton 2. host system: a PC, laptop, handheld, or embedded system. 3. read/write devices can write information to or read information from buttons. It can be the blue dot, pen detector, or handheld device mentioned above. 4. software layer connecting iButton and computer and generating required information in the required format. You can download multiple software development tools (sdks) from your website for free ). For a list of sdks and download links, see this page. What is the cost of designing a simple iButton application? Add programming time, less than $50 (US $ ). The iButton unit price is between $2 and $95; there is a discount if a large order is made. The blue dot receiver and the 1-wire adapter can form a simple read/write device at a cost between $38 and $43. The onewireviewer demo software and SDK can be downloaded free of charge from the website. What are the advantages of iButton over other technologies? When developing an iButton solution, you may think of many complementary technologies. It may be a bar code, RFID tag, magnetic stripe, sensor card, and smart card. Unlike bar codes and magnetic stripe cards, most iButton can read and write data. In addition, iButton's communication rate and product range far exceed the ordinary simple memory used by RFID. In terms of robustness and durability, thin plastic smart cards cannot be compared with the high strength of the stainless steel casing iButtonArticle From Electronic System Design
References: http://www.ed-china.com/ART_8800018471_400001_500007_TS.HTM