imx6ul evk - Arduino pin usage

[giulianofranche]

Hi,

I'm having some trouble using the digital gpios of the arduino header. I'm using the "imx6ul-14x14-evk-btwifi" device tree, but I can't set nor read any gpio.

I've found in the "i.MX 6UltraLite EVK Board Hardware User’s Guide"  that array:

I assumed that, for example, if I want to set the pin D7 high, I'll have to work with the gpio 32*3 + 7 = 103 in Linux. I got no error when I export the pin, write its direction etc... but nothing is happening.

Must I change something in the device tree? I must say I'm not really used to work with these beasts.

Regards

[igorpadykov]

Hi giuliano

on EVK this line D7 is disconnected (R1731 is DNP) from processor

pad SD1_DATA1. SD1_DATA1 is GPIO2_IO19 according to p.183

Chapter 4 External Signals and Pin Multiplexing i.MX6UL Reference Manual

http://cache.freescale.com/files/32bit/doc/ref_manual/IMX6ULRM.pdf

GPIO example with linux is provided on:

Any examples on how to modify the .dts (device tree) source for custom hardware?

Best regards

igor

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[giulianofranche]

Thank you for your answer Igor.

I think there is something I still don't understand. How did you link the D7 pin in the hardware user guide, the R1731, and SD1_DATA1?

I must be blind ...

Thanks for your patience

[igorpadykov · Accepted solution]

one can look at EVK schematic SPF-28616_C.pdf  p.12

Schematics (1)

MCIMX6UL-EVK_DESIGNFILES

Design files, including hardware schematics, Gerbers, and OrCAD files. (REV 0)

http://www.nxp.com/products/sensors/gyroscopes/i.mx6ultralite-evaluation-kit:MCIMX6UL-EVK?fpsp=1&tab...

~igor