[Microbit-Python] A sound related long shot...

[Damien George]

Hi Michael,

Attached is the synth code and the recorded sample.

It's pretty simple, just a PWM loop.  The relevant function is
synth_run, and this is the one that's exposed to Python.

Cheers,
Damien.



On Wed, Oct 21, 2015 at 12:45 PM, Michael <sparks.m at gmail.com> wrote:
> Hi Damien,
>
>
> Really cool to see this :-)
>
> Question - is it possible to get the source for this hex file? I'm very
> tempted to see what would be necessary to get that phoneme playing code
> working on microbit, and having your code for this to see where to start
> would be useful.
>
> :)
>
>
> Michael.
>
> On 16 October 2015 at 14:48, Damien George <damien.p.george at gmail.com>
> wrote:
>>
>> I have managed to get proper synthesised audio out of the microbit,
>> using a hand-written PWM loop.  As a proof of principle, it can play a
>> short recorded sample.
>>
>> Attached is the firmware.  I won't tell you what the sample is, so see
>> if you can find out!  Here are instructions:
>>
>> 1. download firmware.hex to the microbit
>> 2. attach a speaker to pin0 and pin1 (don't use ground)
>> 3. load up the serial terminal
>> 4. execute: synth_run(10, 31, 3)
>> 5. listen in awe!
>>
>> You can adjust the numbers passed to synth_run to muck about with the
>> sample.
>>
>> With this we can basically play any audio, from a mod tracker to a
>> speech synth.  The only caveat is that it can't run in the background.
>> The loop needs full control of the CPU to get the audio to play
>> properly.
>>
>> To answer Nicholas' questions:
>>
>> 1. Could this be done? Yes.
>> 2. Would we want to do it? It would be cool if it (speech synth, or a
>> mod tracker, or ...) was implemented.
>> 3. What would need to happen? We need to find someone with the time to
>> implement it!  It's a fair bit of work (but there are no barriers
>> except time).
>>
>> The SAM software would be ideal, if only it were properly licensed.
>> Otherwise there's a fair bit of work to record all the 49 phonemes,
>> etc.
>>
>> Maybe we can just provide some prerecorded samples (eg "exterminate")
>> and provide functions to adjust the pitch, echo, etc, and combine
>> sounds, and then play them?
>>
>> D.
>>
>>
>>
>>
>> On Fri, Oct 16, 2015 at 1:37 PM, Larry Hastings <larry at hastings.org>
>> wrote:
>> >
>> >
>> > On 10/16/2015 05:23 AM, Nicholas H.Tollervey wrote:
>> >
>> > Hi Folks,
>> >
>> > So I was thinking about the amazing example Larry posted yesterday of
>> > the 20yo calculator turned into a multi-part sequencer with effects
>> > etc...
>> >
>> > Could we do something just as amazing... would we even want to try..?
>> >
>> > Then I remembered - as a child of the 1980s I had an original BBC B at
>> > home and one of the most amazing feats Superior Software pulled off was
>> > a 7.5k program called, simply, "Speech!". To give you an idea of what it
>> > was like I found this on YouTube:
>> >
>> > https://www.youtube.com/watch?v=t8wyUsaDAyI
>> >
>> >
>> > The equivalent for computers manufactured outside Britain was "Software
>> > Automatic Mouth", or "SAM", available for the Apple ][, Atari 400/800,
>> > and
>> > Commodore 64.
>> >
>> > Some enterprising hacker has taken the C=64 version, compiled the
>> > assembler
>> > into messy C, cleaned it up (some), and put it up on Github:
>> >
>> > https://github.com/s-macke/SAM
>> >
>> >
>> > He then used Emscript to translate that into Javascript, and behold: web
>> > page demo.
>> >
>> > http://simulationcorner.net/index.php?page=sam
>> >
>> >
>> > (Aside: cripes, modern computers are fast.  Just imagine how awful this
>> > code
>> > is, and what a Rube Goldberg machine its runtime must be like.  Yet it
>> > runs
>> > in the tiniest fraction of a second.)
>> >
>> > So, thoughts..? Is this even possible..? I imagine a very simple API
>> > such as this:
>> >
>> > import microbit
>> > microbit.say("Hello, World")
>> > microbit.say("Hello, World", pin=microbit.pin1)  # Lke music API
>> >
>> >
>> > Possible, yes.  But I don't know anything about voice synthesis, so I
>> > could
>> > hardly write one myself.  And even if SAM is "abandonware", legally
>> > somebody
>> > still owns the copyright, so I wouldn't ship that specific
>> > implementation.
>> >
>> >
>> > /arry
>> >
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>> >
>>
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