Chapter 2. Interfaces
2.1. Wireless
The CM4 can be supplied with an on-board wireless module based on the Cypress CYW43455 supporting both:
•
2.4 GHz, 5.0 GHz IEEE 802.11 b/g/n/ac wireless
•
Bluetooth 5.0, BLE
These wireless interfaces can be individually enabled or disabled as required. For instance, in the case of a kiosk
application, a service engineer could enable wireless operation and then disable it once finished.
The CM4 has an on-board antenna. If used it should be positioned in the product such that it is not surrounded by metal,
including any ground plane (see Chapter 3 for further details). Alternatively there is a standard U.FL connector on the
module, see Figure 1, so that an external antenna can be used.
Raspberry Pi Ltd has an antenna kit which is certified to be used with the CM4. If a different antenna is used then
separate certification will be required.
WARNING
Raspberry Pi Ltd will not be able to assist with certification for third-party antennas.
The selection of internal or external antenna is done at boot time using the config.txt file, and can not be changed
during operation. The config.txt options are dtparam=ant1 to select the internal antenna, or dtparam=ant2 for the external
antenna.
2.1.1. WL_nDisable
This pin serves a number of functions;
1. It can be used to monitor the enable/disable state of wireless networking. A logic high means the wireless
networking module is powered up.
2. When driven or tied low it prevents the wireless network module from powering up. This is useful to reduce power
consumption or in applications where it is required to physically ensure the wireless networking is disabled. If the
interface is enabled after being disabled, the wireless interface driver needs reinitialised.
NOTE
On CM4 modules without wireless, this pin is reserved.
2.1.2. BT_nDisable
This pin serves a number of functions;
1. It can be used to monitor the enable/disable state of Bluetooth. A logic high means the Bluetooth module is
powered up.
2. When driven, or tied low, it prevents the Bluetooth module from powering up. This is useful to reduce power
consumption, or in applications where it is required to physically ensure the Bluetooth is disabled. If the interface is
enabled after being disabled, the Bluetooth interface driver needs reinitialised.
Raspberry Pi Compute Module 4
2.1. Wireless 5
剩余32页未读，继续阅读
HHONGQI123
- 粉丝: 1331
- 资源: 21
我的内容管理
展开
最新资源
- Hadoop生态系统与MapReduce详解
- MDS系列三相整流桥模块技术规格与特性
- MFC编程：指针与句柄获取全面解析
- LM06：多模4G高速数据模块，支持GSM至TD-LTE
- 使用Gradle与Nexus构建私有仓库
- JAVA编程规范指南：命名规则与文件样式
- EMC VNX5500 存储系统日常维护指南
- 大数据驱动的互联网用户体验深度管理策略
- 改进型Booth算法：32位浮点阵列乘法器的高速设计与算法比较
- H3CNE网络认证重点知识整理
- Linux环境下MongoDB的详细安装教程
- 压缩文法的等价变换与多余规则删除
- BRMS入门指南：JBOSS安装与基础操作详解
- Win7环境下Android开发环境配置全攻略
- SHT10 C语言程序与LCD1602显示实例及精度校准
- 反垃圾邮件技术：现状与前景
资源上传下载、课程学习等过程中有任何疑问或建议，欢迎提出宝贵意见哦~我们会及时处理！
点击此处反馈
