Set active source to TV with cec-client

Question

I have cec-client running on my raspberry pi, and I'm able to switch between active sources HDMI 1 - 4 on my Sony TV with:

echo "tx 4F 82 10 00" | cec-client -s
echo "tx 4F 82 40 00" | cec-client -s

What I haven't been able to achieve is switching back to TV as active source. Since the TV normally has ID 0.0.0.0, I would expect the following command would do the trick, but no response from TV:

echo "tx 4F 82 00 00" | cec-client -s

4 = Recorder 1 (raspi)

F = Broadcast

82 = Active Source

00 00 = ID

Has anyone successfully done this pretty basic operation?

Answer 1

I like tarapitha's answer because it has an explanation.

The TV switchs back to active source if there is no other device that reports to be active (in response to a [Request Active Source] message, so this is the reason why the [Inactive Source] message works.

The only problem is that [Inactive Source] message has to be directly addressed to the TV, so the correct frame would be 40 9d 10 00, if the physical address of the active source is 1.0.0.0

eman's answer probably worked because the TV is forgiving the wrong physical address, it just performs the active source request and finds no active source so sets itself as active.

I recommend this page to understand CEC framing.

Answer 2

try this: echo "as" | cec-client -s