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Electronics => Electronics => Topic started by: pomprocker on February 13, 2010, 12:50:23 PM

Title: wireless voice control w/ baby monitor hack
Post by: pomprocker on February 13, 2010, 12:50:23 PM
i've opened up a cheap baby monitor receiver (parent unit) and disconnected the internal speaker and added wires to a 3.5mm stereo plug.

This plug is going into a usb audio adapter mic in for voice recognition on a linux platform.

However I am getting too much buzz on the line for any recognition to take place.

The speaker has a pos and neg connection, I just wired this up to the tip and ring of the stereo plug for left and right. Is this correct? Or should speaker negative go to the sleeve for ground??
Title: Re: wireless voice control w/ baby monitor hack
Post by: SmAsH on February 13, 2010, 04:36:22 PM
If there are only two wires its a mono connection. Wire it up so neg goes to sleeve and pos either goes to both of the other ones to use left and right channels. Are you sure its not amplified for the speaker eg. screw up the sound card?
Title: Re: wireless voice control w/ baby monitor hack
Post by: Soeren on February 13, 2010, 09:00:39 PM
Hi,

The speaker has a pos and neg connection, I just wired this up to the tip and ring of the stereo plug for left and right. Is this correct? Or should speaker negative go to the sleeve for ground??
Sleeve is allways connected to the negative terminal, the positive terminal is connected to the Tip, in a stereo setup, if it's the left channel, or if it's mono. For stereo, the Sleeve is positive for the right side.

If you connect only Tip and Sleeve to a single speaker in a stereo system, you'll get the sum of both channels (with distortion and diminished volume) and if you play the same signal 180° out of phase, they'll sum to exactly zero.
Title: Re: wireless voice control w/ baby monitor hack
Post by: pomprocker on February 16, 2010, 02:24:05 PM
before I saw your responses I had added an extra wire going from the sleeve to the ground of the baby monitor and it seemed to work.