Quote:
Originally Posted by mmatej
Thanks. Do yo know how to control LEDs using any similiar method?
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There is an LED diagnostic in u-boot bist (using the serial port) that can flash out Morse code "okay" or "fail" on the LEDs. You could look in the u-boot source code for that.
Direct control of hardware needs to be in kernel mode, so would either need a custom loadable kernel module, or a custom kernel loaded with kexec (unless you can find an ioctl() call to do what you want).
I would like to output PWM sound on the LEDs (stereo using the yellow and green LEDs). You could recover the audio with color filters and a pair of photosensors feeding an audio amplifier (powered computer speakers?).
Of course, we can also use a USB OTG sound adapter, with appropriate hardware. I ordered some $1.35USD devices from an ebay store to use on a K4 (when I get some time). You can buy USB host mode cables for less thatn $1USD, or you can just cut a microUSB plug from a cord and solder it into the USB sound adapter.
Or you could use "WiFi Sound" (pipe raw sound to a host PC over WiFi).
