How many conversions can the ADC on the daisy seed do per second?


First post here, I can’t seem to find anything on the specs of the Daisy Seed ADC’s other than they are 16 bit.

I have a project on the Teensy 4 that I would like to see if possible to migrate to the daisy seed.
My main reason is the ADC on the teensy being really noisy. They are 12 bits but in reality only 10 bits because of noise.

I’m wondering if the daisy seed can convert fast enough for my needs. The teensy is very fast with two ADC’s at 1MSps each but it requires you to do 4 or more samples and average them out to get decent results. However I’m still managing to get about 50Khz per sensor for 10 sensors.

I can probably get away with 20kHz per sensor for 10 sensors simultaneously.

Can the daisy seed do that many conversions. 16 bit would be nice but a noise free 12 bit would suffice as well (in case the bitrate can be reduced for speed).


The data sheet has the answer:

That describes the capabilities of the microcontroller - but the specifics of how the ADCs are configured is somewhere in the libDaisy code.

What’s your intended application?

Thanks, I didn’t find that datasheet anywhere, it seems the adc capabilities are way much better and more flexible than the teensy.

It’s a very advanced digital drum. Here is a video from an old prototype demonstrating some of the features although there are many more features on the latest version that I haven’t shown yet.

If I recall correctly, ADC in microcontrollers always have noise trouble which makes their specs unrealistic.

Yeah but the Teensy datasheet says 10 bits realistically and the reason is that there is no AGND and DGND. It’s the same. If the Daisy can read at 12 bits clean it’s good enough. Of course more than that is always good.

Hello @Enes - You may already know about this, but I don’t see anything about it in the conversation so far. There are actually 2 independent sets of ADCs available on the Daisy seed:
1 - The ones ‘on chip’ on the STM32H750IBK6 - “3× ADCs with 16-bit max. resolution (up to 36 channels, up to 3.6 MSPS).” You’d be limited by the pins available on the Seed to less than 36 of course.
2 - The ones on the Daisy seed which are on a separate ‘codec’ chip intended for audio application. This has varied over time depending on availability.

I think you can use both sets at the same time, I don’t know to what extent this is supported by LibDaisy-DaisySP.

Thanks man, I need to scan 10 piezos at the same time and on the teensy I have to start reading two sensors at a time and while waiting for the reading to finish I do calculations on the previous two sensors. I haven’t read anything about the daisy seed yet but as far as I know this can be offloaded to the hardware with DMA. On the teensy you can only read two sensors with DMA and I need 10.

Ah, well the STM32H750IBK6 has pretty incredible IO-DMA capabilities, here’s the blurb about DMA:

4 DMA controllers to unload the CPU
1× high-speed master direct memory access controller (MDMA) with linked list support
2× dual-port DMAs with FIFO
1× basic DMA with request router capabilities

from ST Micro’s web page for the chip:

Cool, are there c++ libraries to get those things to work? It’s way above my skill to get them to work without libraries. I’m going to deep dive in those things when I get it delivered and since the footprint is bigger than the teensy I have to modify my PCB and that will take some time to ship from china.

How is the USB communication? The teensy is ridiculously fast and I can send huge amounts of data for monitoring without messing with the MIDI that is also going over USB.


Good, that will tend to answer your question(s). I’d be interested in including support for your edrum in Zynthian-Zynia assuming it is ‘open source’-‘open hardware’.

It’s not a module, the MCU is inside the drum and it puts out MIDI though USB. You can use it with PC and a drum library like superior drummer or any module that has a USB input and can be triggered with midi.

These features are actually a world first for edrums, noone can detect all 4 articulations like that. Cross sticks are kind of a 40 year old problem.

I’ll see if I decide to open source it when it’s finished.

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