Raspberry Pi Tweaks
Disable HDMI Output
/usr/bin/tvservice -o
Add this line to /etc/rc.local to enable on startup.
Run /usr/bin/tvservice -p to turn it back on.
Disable LEDs
https://www.jeffgeerling.com/blogs/jeff-geerling/controlling-pwr-act-leds-raspberry-pi
Pi Zero
# Disable the ACT LED on the Pi Zero.
dtparam=act_led_trigger=none
dtparam=act_led_activelow=on
All Other Pis
# Disable the ACT LED.
dtparam=act_led_trigger=none
dtparam=act_led_activelow=off
# Disable the PWR LED.
dtparam=pwr_led_trigger=none
dtparam=pwr_led_activelow=off
Disable USB Ports
echo 0x0 > /sys/devices/platform/soc/3f980000.usb/buspower
Add this line to /etc/rc.local to enable on startup.
Run echo 0x1 > /sys/devices/platform/soc/3f980000.usb/buspower to turn it back on.