I got this very cheap bluetooth speaker for under $2 , took it apart to see what is inside and found this chip RDA5856TE
the datasheet for it can be found here
https://github.com/RDA5981/RDA5856/blob/master/Datasheet/RDA5856TE_Datasheet_V0.03.pdfsome other variations of it can be found on the same github
it has its own MCU and DSP core, and some nice features like USB OTG, UART, 12C , i2S ADC, DAC, the list goes on, and apparently according to some posts on twitter the ic goes for 0.60$ from china, however i didn't find it on alibaba,
there is also some sort of free eclips based IDE for it!
I was wondering if anyone else in here have came across it and have some more details like a basic application circuit, where to find that IDE (I am still looking)
it says it has stereo DAC output in the datasheet, but i can only see one DAC output pin, am i missing something? or is that a mistake in the datasheet!