On Tue, Apr 18, 2017 at 10:17 AM, GaCuest gacuest@gmail.com wrote:
Maybe it's easier 3 speakers, a basic speaker directly for the STM32F (when using only the STM32F) and two good speakers, connected to the CM108H, when you use the EOMA68 (in this case the speaker of the STM32F would not work).
as a phone that would be... odd.
but not totally unprecedented. the HTC Universal had an insanely ridiculous number of audio paths. something like SEVEN separate outputs and FIVE inputs - no wonder it needed not just the AK4641 but also a separate TI audio multiplexer IC.
because the screen was flippable there were two separate mics and earpiece speakers, one each on each side. then it had separate stereo speakers built into the base. then there was a headphone jack. and a car stereo mode (with a cable to plug in), *and* bluetooth.
if the chosen EC were capable of handling I2S then it would be reasonable to drop in something like an AK4641 or a really really basic AC97 Audio IC, then use the USB connection between the EC and EOMA68 to emulate USB-audio: job done.
just doing some quick google searches "STM32F072 I2S" it appears that some people have actually successfully done this - one person (admittedly) with an STM32F4 not the F0. on the chibios.com web site someone even posted working demo code.
l.