Help me generate a DTMF using Delphi

[ex4]

Need help in generate DTMF tone with Delphi? A vcl (freeware) or guidance is a great help
thank you

 

[newelltech]

dtmf in delphi

This should be easy to do. Not knowing how you want to use the tones, here are 2 suggestions:

Offline, calculate the terms for 100 msec. and save to a file. In your application, load the file into memory. Then to play a DTMF digit, just send the values for that pair at the sample rate.

If you need to send the tone out the audio port, find DTMF wav files (they're everywhere on the web). Then play the wav file for each tone.

Sorry if I misunderstood the question.

 

[ex4]

dtmf delphi

well, i think the 2nd method is the one that's very easy to implement. I can generate the DTMF tone using software that i've got and played it according the digit i need.
but will my dtmf tone from the soundcard, can be detected correctly by dtmf decoder HT9170B??

 

[newelltech]

delphi generat fsk

There shouldn't be any problems with playing audio data from a wave file as long as you use one of the standard players.
It sounds like you're sending it out the audio (speaker) port.
Just make sure the voltage levels are within the dynamic range of your detector.
Set your detector width to the same as the generated width.
What are you connecting it to?

 

[ex4]

delphi dtmf tones

well, i'm connecting my soundcard from my computer to a FM Transmitter. On the Receiver, i decode it using HT9170B chip. I've once manage to send raw data from RS232 port directly using my FM TX and received it well at 5km away. But with lack of tuning precision the data cannot be received correctly, so i choose DTMF, since it is analog

 

[newelltech]

delphi dtmf decoder

DTMF is generally sent at 5-10 digits per second. If this data rate is ok for your application then DTMF is a good choice - it has high noise immunity, well-designed low-cost receivers and the data bandwidth should be within your FM tranmission bandwidth. If you need higher data rates, you may want to consider FSK . This month's Circuit Cellar has an all-firmware implementation of a simple FSK link that runs at 1200 bps.

Hope this helps.