Frqout problems

Archiver

Hi Folks,

i tried to generate a frquence from the Stamp using the freqout command.
But whatever frequence I trie to get out it will always put out about 50
khz.
What am I doing wrong? Do I have to filter the output? How?
I would need to give out 0 to 10 khz.

Thanks for your help,

Uli


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Archiver

>Hi Folks,
>
>i tried to generate a frquence from the Stamp using the freqout command.
>But whatever frequence I trie to get out it will always put out about 50
>khz.
>What am I doing wrong? Do I have to filter the output? How?
>I would need to give out 0 to 10 khz.
>
>Thanks for your help,
>
>Uli

Hi Uli,

The freqout command generates sound by using PWM. The raw frequency
measured by a counter is very high, with fundamental components up to
110 khz. Yes, you need a filter, which might be as simple as a
10kohm resistor and a 0.01 uF capacitor. The filter also changes the
amplitude, decreasing the output at the 10khz end, so you may need to
compensate for that.

-- Tracy