AVR-Chat

This is exactly what I need, but how to do it in software?
     A high pass FIR or IIR filter?

     Mark


On 24-Jun-12 17:42, Jim Wagner wrote:
> Motorola 2Way radios used this for years. It was called "noise squelch" or something like that. You have a high pass filter that cuts off above the top of the voice spectrum. Amplify and rectify the filter output. You will have a rectified output only when there is nothing to hear on the channel.
>
> Jim
> On Jun 24, 2012, at 10:19 AM, enkitec@gmail.com wrote:
>
>> Hi,
>>
>> I want to build a FM radio squelch using an ATMEGA8.
>> The ADC will be sampling the FM radio audio output and turn on a
>> LED when there is only noise present. The LED will be off when someone
>> is using the channel (no noise, just voice).
>>
>> What is the best way of doing this in software?
>>
>> Thanks for any idea.
>> Mark Jordan
>>
>>
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