search

libre-computer-project / libretech-saled-light

NeoPixels WS2812 SK9822 Userspace Driver for Libre Computer Boards
GNU General Public License v2.0
2 stars 0 forks source link

GXL #1

Open dsx724 opened 4 months ago

dsx724 commented 4 months ago
  1. Lock CPU Frequency sudo cpufreq-set -f 1GHz
  2. Isolate CPUs 1, 2, and 3 and Assign Task via taskset -c
  3. Disable nohz via cmdline by adding nohz=off to /etc/default/grub
  4. Use a Schmitt-Trigger Inverter to handle level shifting, signal conditioning, and inversion for UART.
guysoft commented 1 week ago

What is this list?

dsx724 commented 1 week ago

@guysoft This is the setup requirements for GXL based platforms including S805X, S905X, S905D. As Linux is not an RTOS, scheduling and context switching can result in UART buffer underrun which would cause glitching of the LEDs. The instructions here are requirements for glitch-free operation of the LEDs. The last one is an external hardware requirement for cleaning up the waveforms since LED signal has non-trivial capacitance.