Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A20 => Topic started by: engidea on July 02, 2015, 04:23:30 PM

Title: A20_SOM rev D, gpio 4-1 marked 5.0V in kicad schematics module, possibly wrong
Post by: engidea on July 02, 2015, 04:23:30 PM
Good morning

I am wiring the A20_SOM into a custom board and the label attached to pin 4-1 of the headers seems incorrect
As far as schematics go, pin 4-1 should be 5VEXT

The question is: Can you confirm pin 4-1 of A20_SOM is 5VEXT ?

Thanks !
Title: Re: A20_SOM rev D, gpio 4-1 marked 5.0V in kicad schematics module, possibly wrong
Post by: engidea on July 06, 2015, 02:22:07 PM
Attached to this reply there is a Kicad schematics part that includes the additional connector present in revision D of the SOM and has a few further info added

https://github.com/Engidea/e-datasheet/blob/master/electronic/SOM_OLIMEX_A20/A20-SOM_KICAD_HDR_rev_D.lib (https://github.com/Engidea/e-datasheet/blob/master/electronic/SOM_OLIMEX_A20/A20-SOM_KICAD_HDR_rev_D.lib)

As far as I can tell it is correct, I will know for sure when I will test the board...

On a side note, since I was looking to add a backup battery for the clock I also point to this thread that may interest you
https://www.olimex.com/forum/index.php?topic=3296.0 (https://www.olimex.com/forum/index.php?topic=3296.0)

look for AXP_BACKUP pin in the extra connector

NOTE: You need to use the png image of the board to know where the extra connector is
Title: Re: A20_SOM rev D, gpio 4-1 marked 5.0V in kicad schematics module, possibly wrong
Post by: engidea on July 06, 2015, 06:59:25 PM
Another question, sorry

The following image showing the header position has the numbering of pins

https://www.olimex.com/Products/SOM/A20/A20-SOM/resources/a20-som_dimensions.png (https://www.olimex.com/Products/SOM/A20/A20-SOM/resources/a20-som_dimensions.png)

starting at 1 on the top left

However, the kicad module

https://github.com/OLIMEX/SOM/blob/master/A20/A20-SOM/KiCAD%20connector%20library/A20-SOM.kicad_mod (https://github.com/OLIMEX/SOM/blob/master/A20/A20-SOM/KiCAD%20connector%20library/A20-SOM.kicad_mod)

has numbering starting at bottom left (pin 1)

A simple explanation is that the PNG is actually upside-down

Can any at OLIMEX confirm ?

Thanks !!