diff --git a/baton.lua b/baton.lua
index c43f463..f263d3f 100644
--- a/baton.lua
+++ b/baton.lua
@@ -1,5 +1,23 @@
 local baton = {}
 
+local function parseSource(source)
+	return source:match '(.+):(.+)'
+end
+
+local sf = {kbm = {}, joy = {}}
+
+function sf.kbm.key(key)
+	return love.keyboard.isDown(key) and 1 or 0
+end
+
+function sf.joy.button(joystick, button)
+	if tonumber(button) then
+		return joystick:isDown(tonumber(button)) and 1 or 0
+	else
+		return joystick:isGamepadDown(button) and 1 or 0
+	end
+end
+
 local Player = {}
 Player.__index = Player
 
@@ -50,6 +68,24 @@ function Player:_init(config)
 	self:_initPairs()
 end
 
+function Player:_setActiveDevice()
+	for _, control in pairs(self._controls) do
+		for _, source in ipairs(control.sources) do
+			local type, value = parseSource(source)
+			if sf.kbm[type] and sf.kbm[type](value) > self.config.deadzone then
+				self._activeDevice = 'kbm'
+				return
+			elseif self.config.joystick and sf.joy[type] and sf.joy[type](self.config.joystick, value) > self.config.deadzone then
+				self._activeDevice = 'joy'
+			end
+		end
+	end
+end
+
+function Player:update()
+	self:_setActiveDevice()
+end
+
 function baton.new(config)
 	local player = setmetatable({}, Player)
 	player:_init(config)
diff --git a/main.lua b/main.lua
index 4e996ce..0f769f3 100644
--- a/main.lua
+++ b/main.lua
@@ -15,4 +15,10 @@ local input = baton.new {
 	joystick = love.joystick.getJoysticks()[1],
 }
 
-print(inspect(input))
\ No newline at end of file
+function love.update(dt)
+	input:update()
+end
+
+function love.draw()
+	love.graphics.print(tostring(input._activeDevice))
+end
\ No newline at end of file