[sdiy] wireless patching

[rsdio at audiobanshee.com]

I take that back: ASK/FSK would not require multiple carrier frequencies because you have the option of using TDM to merge multiple signals into one bit stream. That's one advantage of digital FSK over analog FM. I can imagine analog FM solutions for multichannel CV, but they couldn't be received by off-the-shelf parts.

Also, the question of whether you could send any PWM signal can be circumvented by sending the digital value instead of the PWM signal itself. Using 16-bit PWM as an example, the PWM signal would require 4,096 times as much bandwidth as sending the PCM data instead. You can certainly send PCM data over FSK, you'll just need some framing information to identify the bit cells.

Brian Willoughby
Sound Consulting


On May 25, 2017, at 1:52 PM, rsdio at audiobanshee.com wrote:
> FSK and ASK both assume digital input. If you want to send analog data, then you should be able to use standard FM, which can transmit analog signals. So long as the pilot frequency and the signal frequency survive the transmission, you should be able to reconstruct the analog signal on the receiving end.
> 
> I do think that multiple CV would require multiple transmit frequencies and multiple receivers, though, to keep the signals distinct. That would be true with ASK/FSK or straight FM.
> 
> Brian Willoughby
> Sound Consulting
> 
> On May 25, 2017, at 2:29 AM, Roman Sowa <modular at go2.pl> wrote:
>> BT is no good for realtime.
>> How about really simple $2 RF modules that have FSK or ASK input? Not sure if you can freely modulate with any PWM signal or is it quantized to some fixed data rate, but common sense tells me that the simples cheapest module just drive the radio directly.
>> So you have wireless PWM link, and that's just one step from CV.
>> 
>> Roman
>> 
>> W dniu 2017-05-25 o 01:13, Quincas Moreira pisze:
>>> Hey friends!
>>> If you were to design a fast and precise wireless transmission and
>>> reception system for eurorack, how would you doi it? Synth 1 > ADC > uP
>>>> Bluetooth > uP > DAC > synth 2 ?  Or is there a simple analog way to
>>> do it with RF?
>>> 
>>> I mainly want to send control signals, but as we know, those can be up
>>> in the audio frequencies or higher!
>>> 
>>> The idea is to have like, 4 systems set up on 4 corners of a room and
>>> inter-patch them without stretching long cables all over the place. I
>>> think 8 sends and 8 receives on each remote patch box would suffice, and
>>> some system to match sends to receives.
>