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Outputting to a microphone amp — Parallax Forums

Outputting to a microphone amp

Nick McClickNick McClick Posts: 1,003
edited 2009-05-06 22:08 in General Discussion
I've been working on my Xbox live headset adapter for a while. Version 1 amplifies the headset so that you can hear other people better. I'm thinking of doing a version 2, where it helps out with the microphone and I'm looking for some advice;

The primary problem with the headset is the voice operated switch. It takes about 1/2 a second to kick on, so your first word is usually cutoff (or the whole transmission, if you only wanted to say 'yes' or 'no'). I'm thinking there are two ways to fix this;
1 - keep the channel open all the time. The headset will do duplex, but I think the only way to do this is to make a repeating sound (which may get annoying).
2 - Delay the transmission by a half second. This might be the best bet. Have the ucontroller make a startup sound that triggers the vox.

This is beyond my limited capabilities, I'm looking for a little advice.

Question 1: The headset appears to be just like a typical cell phone headset, Tip is microphone, Ring is speaker, and Sleeve is ground. I'm thinking this is an electret condenser mic. What does the circuit look like from the ucontroller to the amp? Just a blocking capaciter? Nothing at all?

Question 2: 8 bit mono pcm at 8kHz should take 8kB / second, right? So I should have enough memory on the hub for my 1/2 second delay?

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Comments

  • LeonLeon Posts: 7,620
    edited 2009-05-04 19:19
    If it is an electret mic it will need a supply. You should connect the plug tip to 5V or so with a suitable resistor - 2k2 should do. Then use a 100nF blocking capacitor on the amplifier input.

    Leon

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    Post Edited (Leon) : 5/4/2009 7:24:23 PM GMT
  • mikedivmikediv Posts: 825
    edited 2009-05-06 22:08
    Hey Nick I don't mean to hijack your post but I wanted to thank you for sending me the chip,, I am very happy with the way you have treated me and the boards that I bought,, guys Nick is very decent he went above and beyond what I was expecting,, Thanks again Nick
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