Daisy Seed - use of MCU and other components

[mrShadow785]

Hi everybody,

I’m starting to get more interested in the daisy platform and especially what’s inside it globally.
According to my research, it is mainly composed of 3 blocks:

• a SMT32H750ib: ARM Cortex-M7 MCU
• a SDRAM (64MB)
• an external audio codec: PCM3060PWR

I can’t find precise “daisy documentation” on these components and I’d like to validate with you if these are the right ones.
I also have a few questions:

• What is the purpose of the SDRAM and the audio CODEC? The STM32H7 is already very powerful, these two components just make the overall platform even more performant?
• Is it possible to develop with the STM32 environment instead? With STM32 libs for the DSP and STM32Cube IDE?
• Would there be any real added value in working on the STM32 environment with its IDE, or using VS Code with the libs created by Electrosmith, which already do the job well?

Thanks in advance for your interest.

[dreamer]

SDRAM can be used to temporarily store audio in a buffer. You can use this for things like looping, delays and reverbs.

Without the CODEC the Daisy would not have any audio input or output. So the CODEC is what makes the Daisy an audio platform.

There are various programming environments that you can use with Daisy. Which one is more suitable for you depends on what you want to do with the platform.

The libDaisy project has some information on audio and SDRAM.

[tunagenes]

The codec varies over time depending on which chip is available (not discontinued). See this post for details:

Rev5 seed producing ~13dB higher noise floor

To address your question, I feel some Daisy-History is necessary, but the short-version is that the difference in noise floor is related to the codec installed on the board. The original release of Daisy Seed (rev4) had the AK4556 codec installed. The AKM factory that manufactured that codec burned down due to a fire in 2020. Unfortunately, the end result was the part being discontinued, with no plans of continuing to manufacture it. In order to keep Daisy alive despite this, and to be able to…

and this topic seems more current:

Rev 7 noise floor vs Rev 4

I have both of these and the Rev 7 is significantly noisier than the Rev 4. I read that the earlier rev used an AKM codec that isn’t available anymore, but Rev 7 uses the PCM3060, which is supposed to be an improvement over the WM8731 used in Rev 5. I’m measuring 40uVrms noise from Rev 4, and 225uVrms for Rev 7, plugged into a Terrarium with the digital audio out set to 0. That’s 15dB difference and too much for a guitar level input. The WM8731 was claimed in another thread to be 11dB max above…