Tone Decoding help, Please?

SSchaaf

Hello,
Can anyone tell me, or better yet, POINT me to were I can find examples of code for a BS2 to decode 1400hz, 1800hz, and 2300hz tones, and possibly COUNT the number of these frequency pulses?

The usual sequence is to:
1. Decode the phone ring pulses, (20hz)
2. Answer and send a 1400hz tone for 1sec
3. Detect and count either a 1400 or 2300hz tones.
4. Detect if tones were sent at 10 pps, 20 pps, or 40pps.
5. Send 1400 or 2300hz kiss-off tone for 1 sec.

Any help would be GREATLY appreciated!

Thanks,
Scott...

Jon Williams

Ideas: You could use a modem to answer the phone (after the proper number of rings). Then, take the audio from the modem and square it up through a flip-flop. Use PULSIN to measure the frequency input. You can use (filtered FREQOUT) -- injected in to the audio input of the modem -- to send the tones back

Have a look at our Modem AppMod and the commands referenced above.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

SSchaaf

Thank you for the fast response! I have a couple more questions tho....

1. Does the audio in and out of a modem allow all audio from the phone line thru?

2. PULSEIN will read the freq, how do I count the pulses, and the pulse RATE?

Thanks again,
Scott...

Jon Williams

The modem we use on our Modem AppMod does have audio in and out, but we don't bring those connections out to pins -- you'll have to add wires. Measuring frequency with PULSIN is done with the forumua F = 1 / T.

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Jon Williams
Applications Engineer, Parallax
Dallas Office

SSchaaf

Thanks again. How do I count the frequency PULSES tho? I need BOTH, the frequency AND the number of these pulses.

Thank you so much so far,
Scott...

K de Jong

Number of pulses = frequency x time

Klaus

SSchaaf

Thanks Klaus, BUT, I am already reading the frequency OF the pulses, How do I detect when one ends, and another begins, THEN how many total?

Scott...