On Wed, Oct 21, 2015 at 12:08 PM,  <[email protected]> wrote:
> I have a BBB running Debian Wheezy, kernel 3.8.13-bone70. I have a 4D
> systems LCD cape that I can attach to my system and the LCD cape will start
> up and run without any problems. The display datasheet is here.
>
> I'm trying to make a custom cape using the same display. My custom cape does
> not have the LEDs, power, reset, up, down, left, and right buttons, as well
> as no EEPROM. I have verified my own schematic comparing the relevant
> points, and everything seems to check out. I have also verified that my
> display pinout matches the circuit board(s).
>
> The kernel can be forced to load the cape in the uEnv.txt file. I have
> modified this file to load the cape on startup.
>
> What I'm seeing is as follows:
>
> After the OS has loaded, the PWM for the display backlight is actually
> triggering on the heartbeat. My pins are correct schematically, I've
> verified this. The PWM output is actually triggering on the heartbeat, I've
> verified this using a multimeter and probing the output from the BBB. Also,
> there is no backlight created in the /sys/class/backlight directory.
>
> After disabling the trigger on the backlight, I just set the backlight to
> output the max value. However, nothing is showing up on the screen.
>
> I have also noticed that the the 4D systems cape actually loads the 00A1
> revision of the overlay, but the uEnv.txt file tries to load the 00A0
> revision. I did not have the 00A0 revision, so I copied the 00A1 file and
> re-named it as the 00A0 file. The cape manager accepted this and loaded the
> file. Is there some way to specify loading the 00A1 revision?

Use a ":" like:

BB-BONE-LCD7-01:00A1

Regards,

-- 
Robert Nelson
https://rcn-ee.com/

-- 
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