[Arm-netbook] ZeroPhone

[Luke Kenneth Casson Leighton]

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crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68


On Mon, Apr 17, 2017 at 7:26 PM, GaCuest <gacuest at gmail.com> wrote:
> El 17 de abril de 2017 a las 14:30:27, Luke Kenneth Casson Leighton
> (lkcl at lkcl.net) escribió:
>> > Why not use the STM32F072 for audio on the laptop?
>>
>> not good enough dynamic range and quality, and it is still necessary
>> to have a amplifier. i tried doing audio on an STM32F103RBT6 - i
>> learned that it would not be enough. i *almost* managed it though.
>>
>
> Could you use one (poor quality) speaker for the STM32F and when
> you connect an EOMA68, could you use a CM108AH with one
> (or two) good speakers?

 might be a bit awkward, multiplexing the analog power-pathways (the
CM108AH drives its outputs @ either 100mA or 500mA) but it's doable.

 the other alternatives are:

 * to add a proper I2S audio driver IC (from maxim for example).
however as these typically include a tensilica DSP (tensilica have
over 1 billion licensed sales of their DSPs, mostly in audio ICs)
they're typically relatively costly.

 * to drive something like a CM108AH directly from the EC.  this
gets... a little hair-raising with the USB paths.

 * to find an alternative EC.

 l.