Check the SRM. gpio2_8-11 are mapped to LCD_DATA2-5 which map to
SYS_BOOT2-5.
The pins are connected to voltage dividers. SYS_BOOT2 is also connected
to uSD BOOT button.
If you load these pins during boot, your BBB may not boot correctly.
Chad
On 11/11/15 5:55 AM, Mihai Seba wrote:
Hi guys!
I have a strange problem with my beaglebone black board and I couldn't
find a solution. I created/generated some device tree files for some
IOs and I observed that for some pins, have a " default" high voltage.
I mean that after I load the dtbo, on those pins set as inputs with no
pull-up/down and with no input connected, I can read value 1 instead
of 0 as normally.
For example, on P8_42 I have this behaviour and this is the device tree:
/*
* This is a template-generated file from BoneScript
*/
/dts-v1/;
/plugin/;
/{
compatible = "ti,beaglebone", "ti,beaglebone-black";
part_number = "BS_PINMODE_P8_42_0x2f";
exclusive-use =
"P8.42",
"gpio2_11";
fragment@0 {
target = <&am33xx_pinmux>;
__overlay__ {
bs_pinmode_P8_42_0x2f: pinmux_bs_pinmode_P8_42_0x2f {
pinctrl-single,pins = <0x0b4 0x2f>;
};
};
};
fragment@1 {
target = <&ocp>;
__overlay__ {
bs_pinmode_P8_42_0x2f_pinmux {
compatible = "bone-pinmux-helper";
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&bs_pinmode_P8_42_0x2f>;
};
};
};
};
I noticed this behaviour only for P8_43,P8_44,P8_41 and P8_42. For
others IOs pins that have similar device tree files ( set up as
inputs, with pullup/down disabled, in mode 7->gpio) everything seems
perfect.
Can someone tell me why only for those 4 pins I have that behaviour?
I have installed Debian OS with kernel version 3.8.13-bone79 .
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google
Groups "BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to [email protected]
<mailto:[email protected]>.
For more options, visit https://groups.google.com/d/optout.
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups "BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
