STM32L496 with a external 6 channel parallel ADC.

[Edward Jang]

Posted on April 13, 2018 at 10:39

I am firmware engineer. But I am a beginner for ST.

I try to get 6 channel ADC 16bit data in high spped by DMA.

Now, I have a nucleo-L496ZG board and a TI ADS8364 ADC board.

- STM32L496ZG (with FMC)

- TI ADS8365 (6 Channel simultaneous sampling SAR parallel ADC).

1)

One person says that I can use FMC in it.But I have no experience to use FMC/FSMC with parallel ADC.

2)

Or. some article says that I can use 'Parallel synchronous transmission using GPIO and DMA' method to this design.But I have no expereince about it, too.

I can't find two methods in detail document in the internet.

Can you explain two methods for my design in detail? (some HAL source code example, too, if you can)

Or another good design....(some HAL source code example, too, if you can)

[AvaTar]

Posted on April 13, 2018 at 11:14

If I may ask - what is the reason for choosing an ADC with parallel interface ?

An SPI interface would be more than appropriate for the expected data rate, without wasting so much IO lines.

[Edward Jang]

Posted on April 13, 2018 at 11:42

AvaTar, thank you for quick reply.   

I need to read 6 fast ADC data and less CPU usage with DMA. So, I tried to use the ADC.(6 channel parallel ADC (250Ksps) )

[AvaTar]

Posted on April 13, 2018 at 12:03

You can read about any peripheral unit per DMA, including SPI.

Don't know the L496 in detail, but ST's internal ADCs use to support higher sampling rates.

It is up to you if you really need 16 bit resolution (and your hardware design can sustain it).

[RomainR.]

Posted on April 22, 2018 at 17:55

Hi Edward,

Maybe you can take inspiration from this post:

https://community.st.com/0D50X00009XkYPKSA3

L4 device had 3 ADC running at 5Msps with differential mode features and DMA.

I do not know what types of waveforms you need to convert, but I think you can use the internal ADC instead of the external component.

Best regards

[Edward Jang]

Posted on April 29, 2018 at 04:27

I know L4 had 3 ADCs, but they're 12-bit. I want 16-bit ADC...So I try to use an external 16-bit ADC.

[AvaTar]

Posted on April 29, 2018 at 18:09

I want 16-bit ADC...

But do you really need 16 bit, and does your hardware design really sustain that resolution ?

Presume a motor control application were the ADC  is sued for current feedback.

If the control loop works well with 12 bit, you waste your time.

If the least 3 or 4 bits of your 16 bit values are only noise, too.