diff --git a/server/main.lua b/server/main.lua
index 34ee7a6..53782c3 100644
--- a/server/main.lua
+++ b/server/main.lua
@@ -13,7 +13,7 @@ console("Connecting...")
 client:connect("student", password)
 console("Connected !")
 
-if neo ~= nil then
+if neo == nil then
     -- connecte la bande de led sur le pin 21
     neo = neopixel.attach(neopixel.WS2812B, pio.GPIO21, 8)
 end
@@ -37,6 +37,26 @@ function get_public_word()
     return r
 end
 
+function set_color(r, g, b)
+    for i=0, 7 do
+        neo:setPixel(i, r, g, b)
+    end
+end
+
+function blink(positive)
+    thread.start(function()
+        if positive then
+            set_color(0, 5, 0)
+        else
+            set_color(5, 0, 0)
+        end
+        neo:update()
+        tmr.delayms(50)
+        set_color(0, 0, 0)
+        neo:update()
+    end)
+end
+
 function draw_ui()
     cls()
     if playing then
@@ -129,6 +149,7 @@ function handle_letter(len, message, topic_len, topic_name)
     end
     letters_played = letters_played .. message
     if not is_in_word(message) then
+        blink(false)
         lives = lives - 1
         if lives == 0 then
             playing = false
@@ -141,6 +162,7 @@ function handle_letter(len, message, topic_len, topic_name)
         console("du mot...")
         return
     end
+    blink(true)
     if not is_won() then
         draw_ui()
         console(message .. " trouve ! Bien joue !")