Using more than 2 pt8211 boards

MusicalMe

New member
Hi All,

Does anyone know if it is possible to output audio to more than 2 pt8211 boards from a teensy4.0?
I noticed that with the audio design tool, the objects 'pt8211' and 'pt8211_2' use different I2S ports of the teensy.
Is it possible to output audio to multiple pt8211 boards from the various pins of the same I2s port, basically the same as is done with the 'I2S_quad' and i2s_hex' objects for multible STGL5000 audio shields?

Thanks.
 
If "possible" means can be done with the existing audio library, then no, using more than 2 of these chips isn't supported.

But if we're talking about what ought to be theoretically possible with a tremendous amount of work in the software, then yes, I believe it should be possible to connect up to 4 of these chips to the first port, similar to how the 8 channel I2S can output 2 strereo streams on the 4 data pins. Of course, using a 5th chip on the other port would still work, since the 2 ports are independent. But no software exists to support this, so it would involve quite a lot of low-level programming inside the audio library.
 
Sorry for hijacking the topic, but is there any documentation on how to wire 2 pt8211 with the library?
 
Two separate pieces of documentation do exist, one for each port.

https://www.pjrc.com/teensy/gui/?info=AudioOutputPT8211

https://www.pjrc.com/teensy/gui/?info=AudioOutputPT8211_2

On each, look for "Hardware" on the right side documentation panel for the specific info about how to wire each. All the other audio library features are also documented this way.

So far there isn't a single document showing use of both together. Likewise for nearly all possible combinations of audio inputs and outputs, the documentation is for each individual feature. However, the design tool does have code which "knows" about the hardware resources and logical configuration each input and output requires, so even though there isn't documentation about use of specific combinations, if you drag a combination that can't work onto the canvas, little yellow error icons appear to tell you that combination can't work together. If you give this a try, you'll see no errors appear with those 2 PT2811 outputs on the same canvas. But if you try to create a 3rd instance of either, or if you drag any of the I2S ones onto the same canvas, you'll see those little yellow errors appear.
 
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