Hi All,
First time posting here, so please correct me if I have posted in the wrong section...
We have a 3GPP/GSM module (Telit HE910) with a 16 bit PCM/DVI digital audio bus (running 512Khz) which is running uLaw audio.
We are looking for a solution that would allow us to attached a DSP, or other integrated circuit, that can detect frequencies such as 100mS 1400Hz pulse (similar to modem handshake tones) and be able to transmit DTMF tones in response. Basically we are doing a very old custom alarm format where we detect a tone, and respond with a series of DTMF tones.
I have a solution that is expensive and was hoping that we could use a low cost DSP to detect 1400Hz/2400Hz and transmit DTMF tones as required. I have not done anything in this area before so not really sure where to start. Target build cost for 10Kpcs is sub USD$5 (or there abouts).
If anyone has existing design or can "easily" do this, please inbox me and maybe we can make some arrangements :)