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fermino · 01-31-2021, 06:21 PM

So, technically it should be possible to put a 3.5mm jack, but it would require a custom board that talks to the processor in the Kobo (and converts the digital signal to analog), that if and only if the processor pins for the I2S bus are accessible and we find/make a driver for that. Anyways, I see a lot of headaches on that one.

But the 4th is actually quite simple. I mean, for sure it will take some time to have it all working, but once it does making the receiver is actually not that hard.

We'd need to choose an audio compression scheme that is a good tradeoff between quality and speed (I'm pretty sure we should go with UDP here, to start maybe uncompressed audio would be better) and then have that talk to an ESP8266 (it's a programmable chip with an integrated wifi controller). Then that board would talk to a digital to analog converter that goes to the jack.

If there's enough space, we could even jam it inside the Kobo, in the meantime, I found this: https://github.com/chunter1/ESP8266_WLAN_speaker

It still uses PWM so the quality is kind of crappy but it might give us some hints about the streaming part.

We shall see

Btw, we don't need IceCast, if we can make it work with ffmpeg/avconv, which is, if we can make it work in any Linux pc, it shouldn't be too hard to make it work on the Kobo, that should ease things up a little bit.

01-31-2021, 06:21 PM	#6
fermino Member Posts: 10 Karma: 20000 Join Date: Jan 2021 Device: Kobo Clara HD	So, technically it should be possible to put a 3.5mm jack, but it would require a custom board that talks to the processor in the Kobo (and converts the digital signal to analog), that if and only if the processor pins for the I2S bus are accessible and we find/make a driver for that. Anyways, I see a lot of headaches on that one. But the 4th is actually quite simple. I mean, for sure it will take some time to have it all working, but once it does making the receiver is actually not that hard. We'd need to choose an audio compression scheme that is a good tradeoff between quality and speed (I'm pretty sure we should go with UDP here, to start maybe uncompressed audio would be better) and then have that talk to an ESP8266 (it's a programmable chip with an integrated wifi controller). Then that board would talk to a digital to analog converter that goes to the jack. If there's enough space, we could even jam it inside the Kobo, in the meantime, I found this: https://github.com/chunter1/ESP8266_WLAN_speaker It still uses PWM so the quality is kind of crappy but it might give us some hints about the streaming part. We shall see Btw, we don't need IceCast, if we can make it work with ffmpeg/avconv, which is, if we can make it work in any Linux pc, it shouldn't be too hard to make it work on the Kobo, that should ease things up a little bit.