[PD] Data in audio / modem

hans w. koch hansw.koch at gmail.com
Sun Aug 20 11:18:55 CEST 2017


how about encoding it normalized to 0. - 1.as amplitude in 3 sinewaves, about 1 octave (or better some non-harmonic spacing) apart and then separating the sinewaves with sigmund or fft?
probably depends on how much precision you need to have.

cheers
hans

> Am 20.08.2017 um 09:59 schrieb cyrille henry <ch at chnry.net>:
> 
> 
> 
> Le 19/08/2017 à 23:18, Max a écrit :
>> On 2017년 08월 19일 23:03, cyrille henry wrote:
>>>> If I'd would want to encode (sensor) data in an audio signal, how would I go about that? 
>>> 
>>> if the sensor output analog value, i'll just use 2 AOP : 1st one to create saw waveform and the 2nd one as a comparator to create a PWM rectangle wave.
>>> 
>>> in pd side, you can use >~ 0 and a lop~.
>> I'm not sure I understand. What's an AOP?
> sorry, I mean OPAMP (AOP is the french term)
> This solution is to convert the analogue value to high/low ratio of a rectangle wave
> 
> 
>>> if you want somthing more reactive, you can encode the sensor valuee in a frequency (using a VCO)
>> Like a pair of osc~ and sigmund~ (attached)?
> in your example, the sensor change the amplitude of the signal. Since you where asking for "a volume independent solution", I propose changing the frequency of the signal.
> 
> 
>> I need 3 values of 7 bit in one channel.
> oh, 3 sensors on a single audio channel : it's a bit much for a simple solution. At least using only analogue electronics.
> 
> if you have a digital system to encore the data, you can use a PPM signal.
> https://en.wikipedia.org/wiki/Pulse-position_modulation
> http://www.fpv-hero.de/Images/PPM1.jpg
> 
> 
> You can also send value as serial data at 9600 b/s
> 
> can you tell us more about your setup?
> why can't you use usb to get the value?
> 
> 
> cheers
> c
> 
>> _______________________________________________
>> Pd-list at lists.iem.at mailing list
>> UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list
> 
> _______________________________________________
> Pd-list at lists.iem.at mailing list
> UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list




More information about the Pd-list mailing list