Daisy Hardware Manual?

I have the Daisy datasheet but that doesn’t really describe the pins well. As I’m not knowledgeable about STM32 things (yet) I find the two and three functions per pin confusing. Probably described in a software doc but they should be described in a hardware doc. Having trouble driving a Maxim Adafruit MAX98357. Using SDA, FS, SCLK on left side of Daisy but it emits a nasty sound unless a scope probe is put on SDA. I’m confused by the I2S pins in purple - where are they described? Should I connect to them instead of the other pins? What are the power capabilities of the 3.3V digital and analog supplies…?

On the Daisy pinout as seen on the Electro-Smith Website, the pins you’d use for an I2S device would be the SAI2 pins, 31-35.

There isn’t much documentation for Daisy, but there is source code for the software (example programs, libDaisy and DaisySP), and reference schematics on the Electro-Smith GitHub. Other details can be gleaned from Google on how I2S is used, and plenty of info on STM32 programming.

MAX98357 details can be found in the MAX98357 datasheet, and the Adafruit 46 page document about the MAX98357 breakout board.

Daisy isn’t the easiest system for beginners, but many have survived.

My question: why are you using MAX98357 with Daisy? Daisy already has a Codec for stereo audio input and output on I2S. This is the first time I’ve looked up MAX98357 - it’s got me interested in trying one (or two) with a Pi Pico.

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It’s actually my son’s project and he’s 2 states away from me. But I have a Daisy as well so I’m curious as to why this happens. I just bought the maxim part on Amazon to see for myself. I suspect it may have to do with him using the daisy 3.3v supply for it or perhaps the SD pin needs to be biased differently.

I’m still curious about reason for using this part with Daisy.

I suspect because the Maxim part contains an amp and connects directly to a speaker.
But yeah, he could bypass I2S totally. I don’t really know - his project is eventually more complex than just these two parts.

That’s what I figured, though an audio chip seems simpler. Maybe the relatively high power is desired.

Getting back to the initial question, the Daisy Seed and all the products built around it (Pod, Petal, Field, etc.) are all based on the STM32H750IBK6.

You can find pointers to all the supporting doc, tools, [eval boards], etc at:

Lots of info in the datasheet:

and an avalanche of info in the 3000+ page reference manual:

Using SDA, FS, SCLK on left side of Daisy but it emits a nasty sound unless a scope probe is put on SDA.

Do you mean when you put a scope probe on SDA it works and when you take it off it fails? If so I would think a small (few pf) cap on SDA might be a ‘solution’.

Thanks, I’ll check that stuff. Yes, the probe can be unplugged from the scope and it still “fixes” it. Interesting issue.

That symptom sometimes means that something, usually an op-amp, is having unintended oscillations.