SD player UI development

[jkeny]

So you mean the I2S ports have no way to run in 'slave' mode? That being sync'd to an externally driven clock input.

In master-mode it generates MCLK using PLL from system clock.
Yes, it can be operated in slave mode & documentation says this about transmitting in slave-mode

"When I2S is configured to slave transmitting mode and this bit is set, the module will wait for the master BCK clock to enable a transmit
operation."

Which means that there is no MCLK input & it seems some logic is needed in the ESP32 to send enable signal to switch between clocks speed families depending on samplerate of audio file & also, outside the ESP32, some logic needed to generate a BCK based on samplerate, which it then uses to synch the transmission of I2S-LRCK & I2S-DATA.

[nige2000]

Id be looking for audio frequency input too

[jkeny]

Id be looking for audio frequency input too

That's what I mean by sample rate or do you mean something else?

[nige2000]

I2s clocked at sample rate frequencies from good oscillator

[jkeny]

I2s clocked at sample rate frequencies from good oscillator

Yea, that's what I'm saying is needed but the clock needs to be synchronous i.e. used by ESP32 for I2S as well as the same clock used by external reclocker. In other words mclk needs to be an input to ESP32 & that's not an option, as far as I can tell - only bclk can be an input signal.

[nige2000]

I2s clocked at sample rate frequencies from good oscillator

Yea, that's what I'm saying is needed but the clock needs to be synchronous i.e. used by ESP32 for I2S as well as the same clock used by external reclocker. In other words mclk needs to be an input to ESP32 & that's not an option, as far as I can tell - only bclk can be an input signal.

could use a potato 74 chips to freq divide 22/24 down to bitclock speeds?

[jkeny]

I2s clocked at sample rate frequencies from good oscillator

Yea, that's what I'm saying is needed but the clock needs to be synchronous i.e. used by ESP32 for I2S as well as the same clock used by external reclocker. In other words mclk needs to be an input to ESP32 & that's not an option, as far as I can tell - only bclk can be an input signal.

could use a potato 74 chips to freq divide 22/24 down to bitclock speeds?

If we want to be able to play more than one particular bit depth/ samplerate we need to be able to change the MCLK divider to derive BCLK - that requires some logic, I reckon - maybe it can all be driven by ESP32, don't know?

If we are looking to program a chip then it should handle all sample rates/ bit depths - I'm not interested in solutions that can only play one bit depth/samplerate audio file

[randytsuch]

Thought I'd give this thread a kick with my latest (but likely not last lol) thoughts on this subject.

Based on the player thread, looks like Panny SLC SD cards will sound better than flashair card, but using a normal SD card I'd have to make a big sacrifice in usability.

Started looking at other options, I remember someone mentioning micro sd adapter cards with wifi, so I searched for those, see what's available.
They look to be aimed at digital cams, which made sense before digital cams had wifi.

So there are other sources of wifi sd cards and adapters, but they are not open source like flashair, which is the bad news. But the good news is people have figured out how to hack into some of them, as some of these just run embedded linux.

I've found details on getting into transcend wifi cards (they have flash built in) and pqi air adapters. I'm planning to get a pqi, and see what I can do with it. Figure if I can log in as admin or root in linux, I should be able to get it to act as a file server, and be able to write and delete files from the sd card.

[jkeny]

Great, Randy, keep it up. Sorry I can't put the work into this that's needed - too busy at the moment with other things - hope by next week to have freed up my time.

[randytsuch]

I'm also working on another project, but spent just enough time to find these wifi options.

https://github.com/ProjektMedInf/ProjMe ... iCardHacks

Looks pretty easy to reflash the card, and then have a console port interface.
Then see if I can install samba on it.