Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: IvanSB on June 16, 2021, 03:44:57 PM

Title: DOCS: Pin assignment with default image LIME2 + CS on SPI
Post by: IvanSB on June 16, 2021, 03:44:57 PM
Hi,

Is there some place where I can get the pin assignment with the default Olimex Debian image? (5.10.36).

I already have A20_LIME2_GPIOs.pdf but same function can be assigned to different pin.

I can see /dev/spidev1.0 and /dev/spidev2.0 but I don't know what pins have been assigned to these devices.

Same problem is going to repeat if eg. I was planning to use USART etc...

I was planning to download sources and overlay to get a clue but there are some dead link in OImage-guide.pdf (5. Build information and sources).

I was also wondering, once I discover to which pin the /dev/spi are related if the CS pin is configured to be controlled by hardware (auto-raise/fall every time I send messages) or I've to pick up a GPIO pin as a CS signal and raise/lower it via software.

Thanks.
Title: Re: DOCS: Pin assignment with default image LIME2 + CS on SPI
Post by: LubOlimex on June 16, 2021, 04:40:28 PM
You can find assignments here:

https://github.com/OLIMEX/olinuxino-overlays/tree/master/sun7i-a20

For SPI1 for example check this file:

https://github.com/OLIMEX/olinuxino-overlays/blob/master/sun7i-a20/sun7i-a20-spi1.dts

You see CS is also defined.
Title: Re: DOCS: Pin assignment with default image LIME2 + CS on SPI
Post by: IvanSB on June 18, 2021, 11:27:12 PM
Thank you very much.

Unfortunately I don't understand/remember from where I got a crippled OImage-guide.pdf.

I recently did some cleanup in my docs folder and I deleted all duplicates so I can not even recheck if there was an actual error in the pdf or it was a temporary failure or my pdf reader suddenly decided to misbehave.

I just remember one of the links was seriously mangled and didn't have a proper http link and another one was pointing to a 404 on github.

So I checked once more in my doc folder and the copy there was fine... and most curiously it says that there has been just one revision dated 4/6/2021.

But anyway you really did solve my problem and with that document with all the link working I guess I'll be able to solve even more.

Very nice products, software support and documentation.

Waiting to see A64-OLinuXino stabilize.