Digital-electronics 简明教程

Digital Electronics - Keyboard Encoders

keyboard encoder 是一种电子设备，用于计算机外设，主要用于键盘，将击键转换为数字信号。在本章中，我们将讨论键盘编码器的定义、类型和应用。让我们从键盘编码器的基本介绍开始。

A keyboard encoder is an electronic device used in computer peripherals, mainly in keyboards, to convert keystrokes into digital signals. In this chapter, we will discuss the definition, types, and applications of keyboard encoders. Let’s start with the basic introduction to keyboard encoders.

What is a Keyboard Encoder?

将键盘实体键敲击翻译成处理设备可以理解并处理的数字信号的电子电路被称为 keyboard encoder 。它基本上是一类将以字母数字形式表示的信息编码成数字或二进制形式的编码器。

An electronic circuit which is used to translate keystrokes from physical keyboards into digital signals that a processing device can understand and process is known as a keyboard encoder. It is basically a type of encoder that encodes the information represented in alphanumeric form into digital or binary form.

键盘编码器作为物理键盘和计算系统处理单元之间的接口。键盘编码器的主要功能是检测按键并将其编码成二进制格式。此编码信号随后会通过诸如 USB、蓝牙等的通信接口发送到处理系统。

A keyboard encoder acts as an interface between the physical keyboard and the processing unit of a computing system. The primary function of a keyboard encoder is to detect the key presses and encode them into binary format. This encoded signal is then sent to the processing system through a communication interface like USB, Bluetooth, etc.

键盘编码器是键盘等输入设备中的必要组件，因为它们允许将人类数据转换为机器语言。

Keyboard encoders are essential components in input devices like keyboards as they allow conversion of human data in machine language.

Applications of Keyboard Encoders

键盘编码器主要用于键盘等输入设备中，将物理按键敲击转换为处理设备可以处理的数字信号。

Keyboard encoders are mainly used in input devices like keyboards to convert physical keystrokes into digital signals that a processing device can process.

以下键盘编码器的一些应用示例 −

Here are some examples of applications of keyboard encoders −

  1. Keyboards used in desktop computers and laptops.

  2. Keyboard encoders are also used in gaming peripherals like gaming keyboards.

  3. Keyboard encoders are also used in control panels and human-machine interfaces used in industrial control systems and automation equipment.

  4. Keyboard encoders are also equipped in various medical devices such as medical imaging devices, patient monitoring devices, diagnostic systems, etc.

  5. Keyboard encoders are also important components in point-of-sales (POS) devices.

  6. Keyboard encoders are utilized in data entry devices like scanners, handheld devices, etc.

键盘编码器是输入设备中的必要组件，允许用户输入数据到处理系统中。它们在输入硬件和数字处理单元之间创建了一个接口。以上章节重点介绍了键盘编码器的一些常见应用示例。

Keyboard encoders are essential component in input devices allowing users to input data into a processing system. They create an interface between the input hardware and digital processing unit. The above section highlights some common examples where the keyboard encoders are used.

让我们了解一个典型的 8421 BCD 键盘编码器的电路和工作原理，它是各种键盘设计中的一个重要元素。8421 BCD 键盘编码器提供了一种简单有效的方法，可将十进制数字编码成二进制格式，以便使用单片机等数字系统进行处理。

Let us understand the circuit and working of a typical 8421 BCD keyboard encoder which is an important element in various keyboard designs. The 8421 BCD keyboard encoder provides a simple and efficient way of encoding decimal digit into binary format for processing using digital systems like microcontrollers.

8421 BCD Keyboard Encoder

8421 BCD 键盘编码器是一类用于键盘和许多其他需要将十进制数字转换为二进制格式或 BCD（二进制编码十进制数字）格式的数字设备的编码器。

The 8421 BCD keyboard encoder is a type of encoder used in keyboards and many other digital devices where decimal digits are need to be converted into a binary format or BCD (binary-coded decimal).

8421 BCD 键盘编码器的二极管矩阵如下图所示 −

The diode matrix of the 8421 BCD keyboard encoder is shown in the following figure −

8421 bcd keyboard encoder

此键盘编码器使用 SR 触发器存储指定为 Q8Q4Q2Q1 的 BCD 输出位。

This keyboard encoder uses SR flip-flops to store the BCD output bits designated as Q8Q4Q2Q1.

当按下对应于小数“0”到“9”之间任意数字的键时，电源 VCC 将打开相应的二极管，这些二极管进一步连接到触发器的置位 (S) 和复位 ® 输入端。

When a key corresponding to any decimal digit between "0" and "9" is pressed, the power supply VCC turns ON the appropriate diodes which are further connected to the SET (S) and RESET ® inputs of the flip-flops.

在此电路中，所有二极管都以一种方式连接，使每个 SR 触发器置位或复位生成一个 4 位组合，表示 BCD 格式中对应的十进制数字。

In this circuit, all the diodes are connected in a manner that each SR flip-flop SET or RESET to produce a combination of 4-bits representing the corresponding decimal digit in BCD format.

让我们通过一个示例来了解 8421 BCD 键盘编码器的原理。

Let us take an example to understand the working of this 8421 BCD keyboard encoder.

当我们按下“0”键时，连接到触发器 Q8、Q4、Q2和 Q1 的 R 输入的二极管正向偏置。因此，输出将为 0000。

When we press the key "0", the diodes connected to the R inputs of the flip-flops Q8, Q4, Q2, and Q1 are forward biased. Hence, the output will be 0000.

类似地，当我们按下“3”键时，连接到 Q8 和 Q4 的 R 输入的二极管正向偏置，连接到 Q2 和 Q1 的 S 输入的二极管也正向偏置。因此，这将产生 0011 输出。

Similarly, when we press the key "3", the diodes connected to the R inputs of Q8 and Q4 are forward biased and the diodes connected to the S inputs of Q2 and Q1 are forwards. Hence, this produces an output as 0011.

键盘编码器对所有其他十进制数字也以相同的方式工作。

The keyboard encoder also works in the same way for all other decimal digits.

Conclusion

在本章中，我们解释了键盘编码器的功能和应用。此外，我们重点介绍了一种简单的 8421 BCD 键盘编码器的构造和工作原理，该编码器用于各种小型电子设备，如自动取款机、销售点终端、移动电话和许多其他电子设备。

In this chapter, we explained the functions and applications of keyboard encoder. Also, we highlighted the construction and working of a simple 8421 BCD keyboard encoder which is used in various small electronic devices like ATMs, POS terminals, mobile phones, and many other electronic devices.