Fingerprint lock new era of single-chip fingerprint lock design and research (1)

The use of locks in the constantly changing.

From mechanical lock to the lock, lock industry took a huge step forward, but also to people's lives to a significant improvement. And now, "biometric technology" at the global level, is promoting the lock industry and technological innovation, which will lead the "lock" the coming of the era.

According to the lock industry experts statistics, national lock sales each year in more than 22 million take.

After years of market making for fingerprint lock to the surge of demand is growing. According to estimates, including financial, military police, Office, commercial market each year, about 500 million sets of market demand. Civil market mature, each year at least commercial market demand. In the coming years, fingerprint locks locks will be occupying the largest share of the market, became a turning point in China's locks.

It is in this market background, Singapore netalk co., Ltd launched can apply fingerprint locks of SIB8132 fingerprint identification chip.

In this, the fingerprint recognition of professional experience in the chip design to share with our readers.

Overall design

Strictly speaking, the fingerprint lock is an electronic lock.

Just because it is based on fingerprint recognition technology, abandoned the previous electronic locks "password" and "smart card" and use the body's innate biological characteristics of fingerprint, thus reaching technology and humanity of perfect unity. Fingerprint lock in satisfy people's security demands, enabling people to stay away from the "remember password troubles" and "carry cards are afraid of losing" fear, true to the "safe and convenient."

To achieve this kind of "safe and convenient" fingerprint lock, on the overall design of the product from the following aspects into consideration.

First, in the "security", not only preventing destructive unlocking, but also takes into account the non technical unlock.

Using fingerprint identification module, in addition to the key lock, basically you can unlock the Elimination of technical problems.

Secondly, to consider the weight code rate, or call key.

For information on encoding of electronic locks, keys in General not less than 105. As for the use of bio-recognition technology, the key content is more than 256 bytes. Their password strength is far better than the existing password.

Third, the selection of fingerprint recognition and fingerprint device performance directly affects the security of fingerprint lock and ease of use.

Although the "fingerprint key" intensity is high, in theory and practice, there is still a false identification, just such a probability than a password and smaller mechanical key.

Fourth, the fingerprint lock is increased by higher costs.

Fingerprint lock-lock for the smart card, fingerprint lock, did not increase costs. Especially after using SIB8132-chip solution, you can lock the control program and fingerprint recognition program integration in an MCU. This is the current global unique single-chip designs, having already been numerous companies. Around SIB8132 is fingerprint lock input and output modules. These modules include power supply module, fingerprint, keyboard, buzzer, and lock the device driver. LCD/LED display equipment, communication interfaces and debugging interface is an optional module, depending on the product features specifications can make a choice.

Like the locks that ordinary people every day use of the product concerned, a "simple" procedures is very important.

Operation process design to the "simple" and "most logical principles for selection". Lock operations process design requires attention: child features set as independent, reducing key reuse. Operation key times as little as possible, the operation level does not exceed the level 2.

Fingerprint process design

As a general increase in the fingerprint lock, for locks, objectively brought a certain complexity.

Of course this is only reflected in the initial use of fingerprint registration operations, the fingerprint lock operation is very simple.

When you first use the fingerprint lock, you need to store the fingerprint data to the lock control module.

Store fingerprints need to go through the "fingerprint" and a "fingerprint identification". "Fingerprint" of the need to design a friendly action sequences to guide users seamless capture fingerprints. In distinguishing the "fingerprint", according to the "fingerprint quality" gives the feedback information, tips, and help users to enter a better quality of the fingerprint. Storage of fingerprint data is often called a fingerprint template, fingerprint templates have a direct impact on subsequent fingerprint recognition (unlock) accuracy.

In most scenarios the use of the fingerprint lock, relates to the management of the "fingerprint" of the problem.

That is, from a specific administrator to authorize other persons to use the fingerprint lock. "Fingerprint management" including fingerprint, fingerprint remove thumbprint (single), clear the (all). Even including the fingerprint code management, and duplicate registration identification problem.

In security level higher fingerprint lock, may involve the "double means (a) demonstration" — that is, the more personal fingerprint serial validation through to unlock.

These relate to the "fingerprint management" function of demand, the needs of specific scenario to complete the process design.

Core control module design

Fingerprint lock core control module is designed for the core SIB8132 dashboard.

Figure 2 two maps are the fingerprint control panels on the front and back. SIB8132 is a similar ARM7, 32-bit high-performance processor. Working voltage 3.3V, kernel operating voltage 2.5V, maximum operating current 75mA. 256K RAM, ROM makes writing a set passwords, remote control, fingerprint, three persons in one of the applications that extravagance. Size 14 × 10 × 10mm 14mm and two. 100 PIN pin contains 3 set UART, 32-bit I2C GPIO, and auxiliary, 8-bit parallel interface, SPI, rich interfaces. The interface makes it easier for processors and more peripheral connectivity, enabling more powerful fingerprint lock system. Therefore, for the current market "more splices" fingerprint lock programmes, greater SIB8132Competitive advantage. Use the real SIB8132 processor can do single-core "veneer" control module.

Fingerprint capture device selection

Fingerprint capture device is in addition to the core control module outside of the most important peripherals.

It pros and cons of performance relating to the quality of the fingerprint lock. Fingerprint capture device is used to contact the most part, is the source of the fingerprint data generation. Just because it is up to the most frequent contact, so in the selection, durability and ease of use is one of the first considerations. Durability considerations expressed in the finger touch anti-static ability, wear resistance, as well as sensing sensitivity was shipped with the usage count decreased significantly. It is generally believed that optical fingerprint collector head is more durable, and semiconductor direct sensing fingerprint head more sensitive. Ease of use in the consumer's experience. In General, press-type i.e. Planar fingerprint sensor using simple finger press to capture fingerprints. Press-type size usually 15mm-25mm square. In addition, in order to reduce costs, and in order to adapt to the needs of the small handheld devices, there are many such products use sliding or scratched sensor, its size is only around 10 × 5mm square.

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