How to use PHP and HID protocol for human-computer interaction device communication

How to use PHP and HID protocols for human-computer interaction device communication

Introduction
Human-computer interaction device communication is an important link in the field of modern computer applications. It allows people to communicate with computers through input devices Communicate and control. This article will introduce how to use PHP and HID protocol to communicate with human-computer interaction devices, and give corresponding sample code.

1. Understand the HID protocol
   HID (Human Interface Device) protocol is a general communication protocol used for data transmission between computers and external human-computer interaction devices. Common HID devices include keyboards, mice, game controllers, etc. The HID protocol defines a set of standardized commands and data formats for describing the input and output interfaces of the device.
2. Use PHP for HID device communication
   As a popular server-side scripting language, PHP can communicate with HID devices by calling the underlying API through extension libraries. Below is a simple sample code that uses PHP to communicate with a HID device:

In the above sample code, we first open the HID device through the hid_open function, where the parameters 0x1234 and 0x5678 are the supplies of the device respectively Merchant ID and product ID. Then use the hid_write function to send data to the HID device, and the data sent is a byte stream " ". Then use the hid_read function to read data from the HID device. Finally, use the hid_close function to close the HID device.

3. Installation of HID extension library
   Before using the above sample code, we need to install the HID extension library. According to different operating systems, please follow the following steps to install:

• Windows operating system: Download the latest version of the HIDAPI library and unzip it, find the php_hid.dll file in the PHP extension directory, and change Copy it to PHP's extensions directory and add it to the php.ini file. Then restart the web server.
• Linux operating system: Install the hidapi-dev library through the package management tool. Then install the HID extension library through PECL: pecl install hid. Finally, add extension=hid.so to the php.ini file and restart the web server.

4. Read and write operations on HID devices
   Through the above example code, we can implement read and write operations on HID devices. Specific read and write operations need to be performed according to the specific requirements of the device. Before performing read and write operations, we need to understand the specifications of the device's input and output interfaces, such as commands, data formats, etc.
5. Example Application: Controlling LED Lights
   In order to better understand how to use PHP and HID protocol for human-computer interaction device communication, we take controlling LED lights as an example for demonstration. We assume that there is a HID device that can control the switching of LED lights by controlling the transmitted data.

The following is a simple implementation example code:

In the above example code, we control turning on the LED light by sending the command " ". Correspondingly, we can use the command " " to control turning off the LED light.

Summary
The combination of PHP and HID protocol can realize human-computer interaction device communication, providing developers with more application possibilities. By understanding the specifications and underlying API of the HID protocol, we can implement read and write operations on HID devices and implement more application scenarios. I hope this article can help readers better understand and use PHP and HID protocols for human-computer interaction device communication.

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