[PD] LibPd on microcontroller

[Christof Ressi]

Hi, thanks for your answer! I'll definitely have a look at heavy and compare the results with some bits of my own DSP code. 

> How do you plan to output audio 
> from it? It has SPI that could get you to connect to some DACs but 
> nothing of top quality audio. One can also use PWM to simulate analog 
> out.

I actually thought of connecting ADCs and DACs via SPI, I don't need top audio quality, I'm rather looking for cheap effect/sound boxes :-). On the other hand, the ESP8266 also an I2S interface (dedicated to audio). I've seen videos of people streaming and playing mp3 files with it! 

Once I've done my tests (probably not before July), I'll tell my results.

Christof


> Gesendet: Montag, 09. Mai 2016 um 17:37 Uhr
> Von: "Lumis Xulepth" <lumis at xulepth.fr>
> An: "Christof Ressi" <christof.ressi at gmx.at>
> Cc: pd-list at lists.iem.at
> Betreff: Re: [PD] LibPd on microcontroller
>
> Hello !
> 
> On 2016-05-09 17:01, Christof Ressi wrote:
> > Hi,
> > 
> > has anyone experience in using LibPd on a microcontroller?
> > I wanna try to run some rather basic DSP code on this guy here:
> > https://www.olimex.com/Products/IoT/MOD-WIFI-ESP8266-DEV/open-source-hardware
> > There are some existing Arduino/C++ frameworks and I thought I could
> > either write my own small DSP library in C++ or use LibPd.
> 
> I have personally used the ESP8266 with either Arduino or the more 
> low-level C SDK from the manufacturer, I like this platform. I have 
> always wanted to see how much it could achieve in terms of DSP. One 
> missing part, though, is the output. How do you plan to output audio 
> from it? It has SPI that could get you to connect to some DACs but 
> nothing of top quality audio. One can also use PWM to simulate analog 
> out.
> 
> I think LibPd has too much dependencies and is indeed too intensive to 
> run on such small microcontrollers.
> Heavy from EnzienAudio might be a better candidate for this as it is 
> optimised for such environments: https://enzienaudio.com/
> It's used on recent projects such as Hoxton Owl (https://hoxtonowl.com) 
> and Bela (http://bela.io).
> 
> I have personally only made some tests with Heavy so I can't offer more 
> than just sugestions. Still I plan to try it on various hardware 
> platforms from ESP8266 to bigger CPUs.
> 
> Hope that helps
> Lumis/Fergus
> 
> > 
> > I understood that LibPd is completely independed of audio drivers and
> > external libraries and since it's plain C code it should work on
> > everything that can run code. However, I have only encountered LibPd
> > in the context of other applications (processing, openFrameworks) and
> > mobile devices so far. Do you think it could work on an ESP8266? I'm
> > also a bit concerned about efficiency, as computation power is rather
> > limited:
> > 
> > "ESP8266EX is embedded with Tensilica L106 32-bit micro controller
> > (MCU), which features extra low
> > power  consumption  and  16-bit  RSIC. The  CPU  clock  speed  is
> > 80MHz.  It  can  also  reach  a  maximum
> > value  of  160MHz.  Real  Time  Operation  System  (RTOS)  is
> > enabled.  Currently,  only  20%  of  MIPS  has
> > been  occupied  by  the  WiFi  stack,  the  rest  can  all  be  used
> > for  user  application  programming  and
> > development."
> > 
> > Christof
> > 
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