我的总体计划是能够从我的树莓派发送 CEC 命令来执行诸如打开/关闭电视以及连接到电视的其他设备之类的操作。然后我将添加语音识别来发送这些命令……那是另一天。我已经阅读了 CEC，但从我收集的信息来看，如果没有 CEC usb 适配器，您似乎无法直接通过命令行发送 CEC 命令？我已经在我的 pi 上安装了 cec-client 和 libCEC 库，但是当我运行 cec-client -l 时，它没有显示任何设备。
我的问题是，如何在没有适配器的情况下通过命令行从 pi 向我的电视发送 CEC 命令？我是否缺少有关 CEC 的一些基本要素？
更新
除了下面的帖子之外，还有一个在 stackoverflow 的 PI 部分中询问的链接，其中包含我在 .bashrc 中放置的更多 CEC 命令来打开/关闭电视并更改输入
https://raspberrypi.stackexchange.com/questions/5345/raspmbc-send-cec-commands-without-cec-adapter
您可以将命令通过管道传输到 cec-client 二进制文件
echo "on 0" | cec-client -s # turn on the television
echo "standby 0" | cec-client -s # turn it off (standby)
为了完整起见，这些是您可以做的其他一些事情
列出连接的设备
tv# cec-client -l
libCEC version: 3.1.0, git revision: libcec-3.1.0+5-6d68d21, compiled on Fri 8 Apr 15:44:58 UTC 2016 by nacho@tv on Linux 4.1.19-v7+ (armv7l), features: P8_USB, DRM, P8_detect, randr, RPi
Found devices: 1
device: 1
com port: RPI
vendor id: 2708
product id: 1001
firmware version: 1
type: Raspberry Pi
检查所有可用的 CEC 命令
tv# echo h | cec-client -s -d 1
opening a connection to the CEC adapter...
================================================================================
Available commands:
[tx] {bytes} transfer bytes over the CEC line.
[txn] {bytes} transfer bytes but don't wait for transmission ACK.
[on] {address} power on the device with the given logical address.
[standby] {address} put the device with the given address in standby mode.
[la] {logical address} change the logical address of the CEC adapter.
[p] {device} {port} change the HDMI port number of the CEC adapter.
[pa] {physical address} change the physical address of the CEC adapter.
[as] make the CEC adapter the active source.
[is] mark the CEC adapter as inactive source.
[osd] {addr} {string} set OSD message on the specified device.
[ver] {addr} get the CEC version of the specified device.
[ven] {addr} get the vendor ID of the specified device.
[lang] {addr} get the menu language of the specified device.
[pow] {addr} get the power status of the specified device.
[name] {addr} get the OSD name of the specified device.
[poll] {addr} poll the specified device.
[lad] lists active devices on the bus
[ad] {addr} checks whether the specified device is active.
[at] {type} checks whether the specified device type is active.
[sp] {addr} makes the specified physical address active.
[spl] {addr} makes the specified logical address active.
[volup] send a volume up command to the amp if present
[voldown] send a volume down command to the amp if present
[mute] send a mute/unmute command to the amp if present
[self] show the list of addresses controlled by libCEC
[scan] scan the CEC bus and display device info
[mon] {1|0} enable or disable CEC bus monitoring.
[log] {1 - 31} change the log level. see cectypes.h for values.
[ping] send a ping command to the CEC adapter.
[bl] to let the adapter enter the bootloader, to upgrade
the flash rom.
[r] reconnect to the CEC adapter.
[h] or [help] show this help.
[q] or [quit] to quit the CEC test client and switch off all
connected CEC devices.
================================================================================
摘自
https://ownyourbits.com/2017/02/02/control-your-raspberry-pi-with-your-tv-remote/
最新版本的 libcec 将 Raspberry Pi 硬件识别为 CEC 适配器。
通过命令行发送控制命令，基本上：
echo "on 0" | cec-client -s
将打开设备 0（即您的电视）
查看 cec-client 交互式 shell 以获取更复杂的命令