# --- BubbleCam peripheral & power overlays -------------------------------
# Appended to /boot/firmware/config.txt by install.sh (idempotent -- it
# checks for the BEGIN marker before appending, so re-running install.sh
# is safe).
# --- BubbleCam BEGIN ---

# Stock config.txt ends with board-filtered sections ([cm4], [cm5], ...);
# anything appended after those only applies to that board. Reset the
# filter so everything below applies to the Zero 2 W (and any other board).
[all]

# No Bluetooth hardware in use on this board -- disable at the firmware
# level (belt-and-suspenders alongside masking bluetooth.service).
dtoverlay=disable-bt

# Binds the DS3231 to the kernel rtc-ds1307 driver, exposing /dev/rtc0 so
# `hwclock` works natively (see bubblecam-rtc-sync.service) instead of
# needing hand-rolled I2C register access.
dtoverlay=i2c-rtc,ds3231

# I2C1 (DS3231 + BME280) and SPI0 (e-Paper) are both required.
dtparam=i2c_arm=on
dtparam=spi=on

# No audio hardware in use -- don't load the driver.
dtparam=audio=off

# Exposes GPIO18 as /sys/class/pwm/pwmchip0/pwm0 (PWM0, default pin/func
# for the single-channel `pwm` overlay) for Lumen dimming -- see
# bubblecam/hardware/pwm_sysfs.py. Deliberately NOT using pigpio, which
# would need a continuously-sampling background daemon for a value that
# only changes twice a day.
dtoverlay=pwm

# Not needed for a UVC (USB) camera -- avoid reserving GPU memory for the
# legacy camera/libcamera stack.
# start_x=1  (intentionally NOT set)

# Headless -- no display output, so give the GPU the minimum and return
# the rest of the 512MB to the ARM. This is load-bearing: V4L2 capture
# buffers at 3200x1200 are 7.68MB each, and the default 64MB GPU split
# left too little headroom (observed OOM kills during camera bring-up).
gpu_mem=16

# --- BubbleCam END ---