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Electronics => Projects, Designs, and Technical Stuff => Topic started by: ivc on October 26, 2016, 06:52:15 pm

Title: Amazon Echo - is the mic disabled via analog circuit?
Post by: ivc on October 26, 2016, 06:52:15 pm

In this video about Jeff Bezos being interviewed by Walter Isaacson (https://dp8hsntg6do36.cloudfront.net/5801499afd2e616c66000029/d92b17fb-e5bb-4f90-86e7-a2adc2b08bbdlow.webm) at around the 6 min mark, Bezos claims the mute button on the Amazon Echo is physically connected to the mic amplification circuit, making it impossible to enable again via software.

Would be interesting if someone with an Echo could do some inspection and find out if this is true.


Title: Re: Amazon Echo - is the mic disabled via analog circuit?
Post by: NiHaoMike on October 27, 2016, 03:25:15 pm
There do seem to be a few SMD components right under the mute button, I'll have to try working out what they do.
https://www.eevblog.com/forum/reviews/teardown-amazon-echo-dot-2/ (https://www.eevblog.com/forum/reviews/teardown-amazon-echo-dot-2/)
Title: Re: Amazon Echo - is the mic disabled via analog circuit?
Post by: Berni on October 28, 2016, 05:24:26 am
Fun story about mute buttons:
Cisco voip phones have the handset switch connected to the microphone amplifiers mute pin. This is so that when the headset is hung up "on hook" on the phone there is no possibility to listen to the microphone. But what a bunch of hackers found out that there is also a GPIO pin connected to that switch so that the software knows when you picked up the phone.

What they did was use some injected code to switch that GPIO pin in to output mode, this then pulled down the switches signal, making the microphone amplifier turn on and they could stream your top secret conversation out to the internet without the handset being picked up.