Serial Stream from ESP32 >> ESP32

[PacciK]

@pschatzmann is there a way to pipe a URLStream or an ICYStream's data as received, over to another microcontroller (this one with wifi off) over a suitably sized Serial data, for eventual consumption and I2S output in the second microcontroller , without having to resort to ADPCM comp/decompression like in the send-adpcm_framed-receive example ? What do you suggest as a pipeline? ThankYou.

[pschatzmann]

I don't quite understand your question: The audio data transmitted via URLStream or ICYStream is usually mp3 or aac, so it is already complressed with a codec that is much better then ADPCM!

Just make sure that the baud rate is high enough if you want to live play...

[PacciK]

from previous tests, even sending out chunks of 4096 bytes at 2Mb/s worked well ( not sound wise - just the packets arrived intact is what I meant).
Please help me with the correct use of Your library, to do the sychronization it requires.
Following the examples/examples-communication/serial/send-adpcm_framed-receive/send-adpcm_framed-receive.ino , I cannot wrap my head around it.

[PacciK]

What I'd like is the send the chunks as fast as possible to the 2nd MCU, which will then process them at its own pace.

[pschatzmann]

This has nothing to do with my library: I already told you that you need to implement Serial data synchronization to prevent loosing data (eg. using the ctsPin and rtxPin).

Or you could implement a big buffer on the receiving side and implement your own synchronization protocol.

[pschatzmann]

Or you could write to a file to make sure that you don't loose any data assuming that you will never run out of disk space....

[PacciK]

@pschatzmann ThankYou for your patience and interaction.
Your extensive library is nothing short of fantastic, which reflects your abilities.

As a tinkerer / beginner, I think I'm going to give up.
....that cold Beer seemed so close.

[PacciK]

@pschatzmann , if I use a circular buffer for the serial data instead of extra cables for CTS and RTX, perhaps it may work ?
What triggers or headers am I looking for in the incoming stream to know how to control the filling of the circular buffer ?
I want to limit my scope to Icecast/Mp3 streams, no AAC, at a max of 320Kbps.

[pschatzmann]

As long as you send the data faster then you consume it, you will run into a buffer overflow and you loose data.
You can use a digital pin that is linked to the fillment level of a receive buffer to set the sending active/deactive, to build your custom synchronization.

In both cases you would only need 2 cables!

• TX -> RX
• CTS <- RTS

[pschatzmann]

Did you get the Serial Flow Control working ?