Page 1 of 1

SPI first clock pulse

Posted: Mon Jan 13, 2020 7:42 am
by bpastore
Good morning all,
I'm trying to comunicate with an SPI device on a NanoPi Neo core 2 (SPI0) but i have some problems.
I can't connect the CS signal and I have a strange first clock pulse so the device receive wrong data

As you can see the
Cattura_10.JPG
Cattura_10.JPG (66.09 KiB) Viewed 2130 times



Any comments/ suggestions are welcome
Thanks in advace

Re: SPI first clock pulse

Posted: Tue Jan 14, 2020 8:42 am
by igorp
bpastore wrote:
Good morning all,
I'm trying to comunicate with an SPI device on a NanoPi Neo core 2 (SPI0) but i have some problems.
I can't connect the CS signal and I have a strange first clock pulse so the device receive wrong data

As you can see the
Cattura_10.JPG



Any comments/ suggestions are welcome
Thanks in advace


AFAIK SPI works as expected. Which kernel you use?

Re: SPI first clock pulse

Posted: Tue Jan 14, 2020 10:35 am
by v8dave
If you don't capture the SPI when your CS is low, you are probably reading other SPI activitiy on the bus.

You need to setup your logic analyser to trigger capture when your CS goes low.