Hammerspoon Bluetooth Automation

This script automates the process of disconnecting a Bluetooth device when your system goes to sleep and reconnecting it when the system wakes up.

Features

• Automatically disconnects the specified Bluetooth device when the system sleeps.
• Reconnects the Bluetooth device when the system wakes up.

Requirements

1. Install Hammerspoon

• Use Homebrew:

  brew install --cask hammerspoon
• Or download it from Hammerspoon's website.

2. Install Blueutil

• Install via Homebrew:

  brew install blueutil

3. Configure the init.lua File

• Navigate to the .hammerspoon directory:

  cd ~/.hammerspoon/

• Edit (or create) the init.lua file and paste the following code:

  -- Author: @muhammed770
  -- Source: https://github.com/Muhammed770/hammerspoon-bluetooth-automation
  -- Github Profile: https://github.com/Muhammed770
  -- Description: This script disconnects a Bluetooth device when the system goes to sleep and reconnects it when the system wakes up.
  
  local bluetoothDevice = "aa-bb-cc-11-22-33" -- MAC address of the Bluetooth device to connect/disconnect
  local log = hs.logger.new("SleepWatcher", "debug")
  
  local function isBluetoothPoweredOn()
      local output, status, type, rc = hs.execute("/opt/homebrew/bin/blueutil -p", false)
      log.i("Bluetooth power status: " .. output)
      output = output:gsub("%s+", "")
  
      return output == "1"
  end
  
  function handleSleepAndWake(eventType)
      local eventNames = {
          [1] = "System Will Power Off",
          [2] = "System Did Power On",
          [3] = "System Will Sleep",
          [4] = "System Did Wake",
          [10] = "Screens Did Sleep",
          [11] = "Screens Did Wake",
      }
      if eventType == hs.caffeinate.watcher.systemWillSleep then
          log.i("System is going to sleep. Attempting to disconnect Bluetooth device.")
          hs.execute("/opt/homebrew/bin/blueutil --unpair \"" .. bluetoothDevice .. "\"", false)
      elseif eventType == hs.caffeinate.watcher.systemDidWake then
          if (not isBluetoothPoweredOn()) then
              log.i("Bluetooth is powered off. Skipping reconnection.")
              return
          end
          log.i("System woke up. Attempting to reconnect Bluetooth device.")
          hs.execute("/opt/homebrew/bin/blueutil --pair \"" .. bluetoothDevice .. "\"", false)
      else
          log.i("Unhandled event type: " .. tostring(eventType) .. " (" .. (eventNames[eventType] or "Unknown") .. ")")
      end
  end
  
  caffeinateWatcher = hs.caffeinate.watcher.new(handleSleepAndWake)
  caffeinateWatcher:start()
  
  

4. Get Your Bluetooth Device MAC Address

• Run the following command to list paired devices:

  blueutil --paired
• Note the MAC address of your device and replace "aa-bb-cc-11-22-33" in the script above with your device's MAC address.

5. Allow Hammerspoon Access to Bluetooth

• Open System Settings > Privacy & Security > Bluetooth.
• Add Hammerspoon to the list of apps allowed to access Bluetooth.

Troubleshooting

• If you encounter issues with the blueutil path, verify its location by running:

  which blueutil
• If the path differs from /opt/homebrew/bin/blueutil, update the path in the script accordingly.

Notes

• Ensure both Hammerspoon and Blueutil are installed correctly.
• Test the script by manually putting the system to sleep and waking it up.