ADS131A0X

HR AHMD

Other Parts Discussed in Thread: ADS131A04

Hello everyone,

I'am using the ADS131A04 in a custom boar with a kinetis k64 MicroPROC. The problem is that when i'am setting the RESET pin to high and the CS to low , i'am not getting the READY sequence on the MISO. I verified the voltage supply and the CS pin, they are well configured.

here's the schematic :

over 8 years ago

0 Brian Pisani over 8 years ago

TI__Mastermind 38745 points

Hey Leo,

I did not receive the schematic. Can you try attaching it by clicking "Use rich formatting" and hitting the "attach" button?

What may also be helpful is if you have an oscilloscope or logic analyzer image of the frame that includes MOSI, MISO, CS, DRDY, and SCLK (or a few images with combinations).

Regards,
Brian

0 HR AHMD over 8 years ago in reply to Brian Pisani

Prodigy 145 points

Hello her's the schematic :

0 HR AHMD over 8 years ago in reply to HR AHMD

Prodigy 145 points

And the pins M0 M1 and M2 are linked to 3.3voltage supply with jumpers.

0 HR AHMD over 8 years ago

Prodigy 145 points

0 HR AHMD over 8 years ago in reply to HR AHMD

Prodigy 145 points

The RX TX is the signal corresponding to the data that i'am recieving.

0 Brian Pisani over 8 years ago in reply to HR AHMD

TI__Mastermind 38745 points

Hey Leo,

The schematic connections look good.

I apologize I should have been clearer about the logic analyzer shot. I would like to see the time after the DRDY pin goes low and SCLK begins so I can see exactly what data you are sending to the device and what data it is sending back.

Brian

0 HR AHMD over 8 years ago in reply to Brian Pisani

Prodigy 145 points

Hi,

So that's what i'am getting when i'am sending the reset command (Just the MISO and The MOSI are reversed sorry):

0 HR AHMD over 8 years ago in reply to HR AHMD

Prodigy 145 points

Just you have to know that even i send any other command i'am always getting the same response.

0 HR AHMD over 8 years ago in reply to HR AHMD

Prodigy 145 points

Another point that when i'am not sending any command i don't recieve any sequence even when i pull up the reset pin.

0 Brian Pisani over 8 years ago in reply to HR AHMD

TI__Mastermind 38745 points

Hey Leo,

It looks like DRDY is coming high "in the middle" of your SCLKs. Since you have just powered on the device at this point, and your word size is set to 32 bits, you should receive 0xFF040000 from the device when it is ready. Can you take a look at the first 32 SCLKs after DRDY and CS go low to check if that is the word you get?

Regards,
Brian

0 HR AHMD over 8 years ago in reply to Brian Pisani

Prodigy 145 points

Hi again,

No i don't get any response if i don't send any command even when i pull up the reset pin. The DRDY pin is always LOW and the CS pin is always high as the µP never get a response. Even when i toggle CS manually the problem occured.

==>On the first 32 SCLK after power on, MISO = 0

BR.

0 Brian Pisani over 8 years ago in reply to HR AHMD

TI__Mastermind 38745 points

Hey Leo,

It looks like in your picture that there is content on MOSI. What is happening in that picture? The FF040000 will not happen immediately following reset but a while after. Are you saying you never see that sequence?

Brian

0 HR AHMD over 8 years ago in reply to Brian Pisani

Prodigy 145 points

Hi,

Yes in the first picture i'am recieving an ACK=7f82 when i send any command, but if i just pull up the reset pin without sending anything i never see any sequence in MISO.

0 Brian Pisani over 8 years ago in reply to HR AHMD

TI__Mastermind 38745 points

Leo,

If you shift 0x7F82 to the left by 1 bit, it is 0xFF04 which is the ready word. To me it seems that when you send SCLKs to the device, you are getting the correct acknowledgement but that either your software or interface is accidentally shifting it to the right.

Brian

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