waybar bluetooth battery status

bluetooth-battery-waybar-module.sh

#!/bin/bash

ICON_BLUETOOTH=""
ICON_BATTERY_FULL=""
ICON_BATTERY_THREE_QUARTERS=""
ICON_BATTERY_HALF=""
ICON_BATTERY_QUARTER=""
ICON_BATTERY_EMPTY=""
BLUETOOTH_BATTERY_STATUS=$HOME/src/scripts/bluetooth_battery_status.sh

tooltip=""

statuses="$($BLUETOOTH_BATTERY_STATUS)"
if [[ $? != 0 ]]; then
    exit 1
fi


n=0
sum=0
IFS=$'\n'
for status in $statuses; do
    uuid=$(echo "$status" | cut -d' ' -f1)
    name=$(bluetoothctl info "$uuid" | grep -oe 'Name: .*' | awk 'match($0, "Name: (.*)", m){print m[1]}')
    percent=$(echo "$status" | cut -d' ' -f2 | grep -oe '[0-9]*')

    tooltip="$tooltip$name: $percent%\n"

    n=$((n+1))
    sum=$((sum+percent))
done
IFS=' '

avg=$((sum / n))

ICON_BATTERY=""
if [[ $avg -ge 90 ]]; then
    ICON_BATTERY=$ICON_BATTERY_FULL
elif [[ $avg -ge 75 ]]; then
    ICON_BATTERY=$ICON_BATTERY_THREE_QUARTERS
elif [[ $avg -ge 50 ]]; then
    ICON_BATTERY=$ICON_BATTERY_HALF
elif [[ $avg -ge 25 ]]; then
    ICON_BATTERY=$ICON_BATTERY_QUARTER
else
    ICON_BATTERY=$ICON_BATTERY_EMPTY
fi

tooltip=${tooltip%\\n}

echo "{\"text\": \"$ICON_BLUETOOTH $ICON_BATTERY\", \"tooltip\": \"$tooltip\"}"

bluetooth_battery_status.sh

#!/bin/bash

SCRIPTS_DIR=~/src/scripts

get_battery_status() {
    device_uuid=$1
    device_uuid_slug=$(echo "$device_uuid" | sed 's/:/_/g')
    device_upower_path=$(upower -e | grep "$device_uuid_slug")
    if [[ "$?" != 0 ]]; then
        return 1
    fi

    upower_out=$(upower -i "$device_upower_path")
    percentage=$(echo "$upower_out" | grep 'percentage:' | grep -oe '[0-9]*%')
    if [[ "$?" != 0 ]]; then
        return 1
    fi

    echo $percentage
}

# prepare devices to process
connected_devices=$1
if [[ "$connected_devices" == "" ]]; then
    connected_devices=$($SCRIPTS_DIR/connected_bluetooth_devices.sh)
fi
if [[ "$connected_devices" == "" ]]; then
    echo "no bluetooth devices connected" >&2
    exit 1
fi

n=0
declare -A device_batteries
for device in ${connected_devices//\\n/ }; do
    device_battery_percentage=$(get_battery_status "$device")
    if [[ $? != 0 ]]; then
        continue
    fi

    n=$((n+1))
    device_batteries[$device]=$device_battery_percentage
    # echo "$device: $device_battery_percentage"
done

if [[ $n -eq 0 ]]; then
    echo "cannot get battery status for any specified bluetooth device" >&2
    exit 1
fi

# TODO: do something else?
for device in ${!device_batteries[*]}; do
    echo "$device ${device_batteries[$device]}"
done

connected_bluetooth_devices.sh

#!/bin/bash

bluetoothctl paired-devices | cut -f2 -d' ' | while read uuid; do bluetoothctl info $uuid | grep -B8 -e 'Connected: yes' | grep 'Device' | cut -f2 -d' '; done

waybar-config

...
  "custom/bluetooth-battery": {
    "format": "{}",
    "return-type": "json",
    "interval": 5,
    "exec": "~/.config/waybar/modules/bluetooth-battery.sh",
    "exec-if": "bluetooth_battery_status.sh >/dev/null 2>&1",
    "signal": 9
  },
...

Currently requires setting up experimental features for bluetooth: https://wiki.archlinux.org/title/Bluetooth_headset#Battery_level_reporting