How to achieve near field communication through PHP and NFC protocol
Near field communication (NFC) is a wireless communication technology that can be used to achieve simple data transmission between devices. It plays an important role in many application scenarios, such as mobile payment, access control systems, smart tags, etc. This article will introduce how to use PHP and NFC protocol to implement near field communication, and attach code examples.
1. Overview of NFC
NFC uses radio waves for near-field communication between two devices. How it works is that when two devices are in close proximity, a brief communication connection is established between them. NFC can communicate over very short distances (usually a few centimeters) and at a fast communication rate.
2. PHP and NFC protocol
PHP is a commonly used server-side scripting language that can communicate with various protocols. Through PHP and NFC protocol, we can realize reading and writing operations on NFC devices. Commonly used NFC protocols include ISO 14443, ISO 15693, FeliCa, etc.
In PHP, we can use the extension library libnfc to implement communication with NFC devices. Next, we will demonstrate how to use PHP for read and write operations.
3. Read NFC tag
First, we need to install the libnfc library. Under Linux systems, you can use the following command to install:
sudo apt-get install libnfc-dev
Next, we need to install the libnfc extension for PHP. It can be installed through the following command:
pecl install libnfc
After the installation is complete, we can use the libnfc extension in PHP. The following is a sample code for reading NFC tags:
<?php $context = nfc_init(); // 初始化NFC上下文 $nfc = nfc_open($context); // 打开NFC设备 $nfc_tag = nfc_initiator_init($nfc); if ($nfc_tag) { $tag_info = nfc_target_get_info($nfc_tag); echo "UID: " . bin2hex($tag_info['uid']) . " "; echo "卡片类型: " . $tag_info['type'] . " "; } nfc_exit($context); // 退出NFC上下文 ?>
In the above code, we first initialize the NFC context and then open the NFC device. Next, we initialized the NFC reader and read the UID and card type of the NFC tag. Finally, we exit the NFC context.
4. Write NFC tag
In addition to reading NFC tags, we can also use PHP to write data to NFC tags. The following is a sample code for writing an NFC tag:
<?php $context = nfc_init(); // 初始化NFC上下文 $nfc = nfc_open($context); // 打开NFC设备 $nfc_tag = nfc_initiator_init($nfc); if ($nfc_tag) { $data = "Hello, NFC!"; // 待写入的数据 $result = nfc_ndef_write($nfc_tag, $data); if ($result) { echo "写入成功! "; } else { echo "写入失败! "; } } nfc_exit($context); // 退出NFC上下文 ?>
In the above code, we first initialize the NFC context and then open the NFC device. Next, we initialize the NFC reader and write the data to be written to the NFC tag. Finally, we exit the NFC context.
Summary:
Near field communication through PHP and NFC protocol is a powerful and flexible way. By using the libnfc extension library, we can read and write NFC tags in PHP. The above sample code can help you understand how to use PHP for near field communication with NFC protocol. Hope this article will be helpful to you.
The above is the detailed content of How to implement near field communication through PHP and NFC protocol. For more information, please follow other related articles on the PHP Chinese website!