diff --git a/TODO.md b/TODO.md
deleted file mode 100644
index a5405b2..0000000
--- a/TODO.md
+++ /dev/null
@@ -1,4 +0,0 @@
-# TODOs
-
-- Improve button press behavior / performance
-- Add more config options (e.g. temp range)
diff --git a/main.py b/main.py
index 6642f76..f2fbb6e 100644
--- a/main.py
+++ b/main.py
@@ -1,14 +1,16 @@
 from machine import Pin, I2C
 from onewire import OneWire
 from ds18x20 import DS18X20
-from time import sleep_ms
+from time import sleep_ms, ticks_ms, ticks_diff
 from lcd_api import LcdApi
 from pico_i2c_lcd import I2cLcd
-import _thread
+
+# Version
+VERSION = "1.0.0"
 
 # Relais
 relais  = Pin(18, machine.Pin.OUT, value = 1)
-led_onboard = Pin(25, machine.Pin.OUT, value = 0)
+#led_onboard = Pin(25, machine.Pin.OUT, value = 0)
 
 # Temperature
 temp_sensor = DS18X20(OneWire(Pin(28)))
@@ -32,80 +34,103 @@ degree = (
     0b00000,
     0b00000,
     )
-
-# Buttons
-button1 = Pin(17, Pin.IN, Pin.PULL_DOWN)
-button2 = Pin(16, Pin.IN, Pin.PULL_DOWN)
-button3 = Pin(15, Pin.IN, Pin.PULL_DOWN)
-global button1_pressed
-global button2_pressed
-global button3_pressed
-button1_pressed = False
-button2_pressed = False
-button3_pressed = False
+umlaut_a = (
+    0b01010,
+    0b00000,
+    0b01110,
+    0b00001,
+    0b01111,
+    0b10001,
+    0b01111,
+    0b00000,
+    )
 
 def ctrl_relais(active = True):
     if active:
         relais.value(0)
-        led_onboard.on()
+        #led_onboard.on()
     else:
         relais.value(1)
-        led_onboard.off()
-        
-def button_reader_thread():
-    global button1_pressed
-    global button2_pressed
-    global button3_pressed
-    while True:
-        if button1.value() == 1:
-            button1_pressed = True
-        if button2.value() == 1:
-            button2_pressed = True
-        if button3.value() == 1:
-            button3_pressed = True
-        sleep_ms(100)
+        #led_onboard.off()
 
 lcd.backlight_on()
 lcd.clear()
 lcd.custom_char(0, degree)
+lcd.custom_char(1, umlaut_a)
 
 temp_tgt = 28.0
 temp_gap = 0.5
 is_heating  = False
 heat_string = ""
 system_on = False
-system_on_string = ""
+system_on_string = "OFF"
+temp_curr = 0
 
-_thread.start_new_thread(button_reader_thread, ())
+lcd.move_to(0, 0)
+lcd.putstr(" G" + chr(1) + "rbox Manager\n  (Ver. "+ VERSION + ")")
+sleep_ms(3000)
+
+# Buttons
+PIN_BUTTON_1 = 17
+PIN_BUTTON_2 = 16
+PIN_BUTTON_3 = 15
+button1 = Pin(PIN_BUTTON_1, Pin.IN, Pin.PULL_DOWN)
+button2 = Pin(PIN_BUTTON_2, Pin.IN, Pin.PULL_DOWN)
+button3 = Pin(PIN_BUTTON_3, Pin.IN, Pin.PULL_DOWN)
+
+button1_last = ticks_ms()
+button2_last = ticks_ms()
+button3_last = ticks_ms()
+
+def button_action(pin):
+    global temp_tgt
+    global button1_last
+    global button2_last
+    global button3_last
+    global system_on
+    global system_on_string
+
+    if pin is button1:
+        if ticks_diff(ticks_ms(), button1_last) > 750:
+            temp_tgt -= 0.5
+            #lcd.move_to(5, 1)
+            #lcd.putstr("{0:3.1f}".format(temp_tgt))
+            button1_last = ticks_ms()
+    elif pin is button2:
+        if ticks_diff(ticks_ms(), button2_last) > 750:
+            temp_tgt += 0.5
+            #lcd.move_to(5, 1)
+            #lcd.putstr("{0:3.1f}".format(temp_tgt))
+            button2_last = ticks_ms()
+    elif pin is button3:
+        if ticks_diff(ticks_ms(), button3_last) > 750:
+            system_on = not system_on
+            if system_on == True:
+                system_on_string = "ON "
+            else:
+                system_on_string = "OFF"
+            #lcd.move_to(13, 1)
+            #lcd.putstr(system_on_string)
+            button3_last = ticks_ms()
+
+button1.irq(trigger = Pin.IRQ_RISING, handler = button_action)
+button2.irq(trigger = Pin.IRQ_RISING, handler = button_action)
+button3.irq(trigger = Pin.IRQ_RISING, handler = button_action)
 
 while True:
     temp_sensor.convert_temp()
     sleep_ms(750)
     temp_curr = temp_sensor.read_temp(sensor_id)
         
-    if button1_pressed == True:
-        temp_tgt -= 0.5
-        button1_pressed = False
-    if button2_pressed == True:
-        temp_tgt += 0.5
-        button2_pressed = False
-    if button3_pressed == True:
-        system_on = not system_on
-        button3_pressed = False
-
     if system_on == True and temp_curr < temp_tgt - temp_gap:
         is_heating = True
     elif system_on == True and temp_curr > temp_tgt + temp_gap:
         is_heating = False
+    elif system_on == False:
+        is_heating = False
 
     ctrl_relais(is_heating)
         
-    if system_on == True:
-        system_on_string = "ON "
-    else:
-        system_on_string = "OFF"
-        is_heating = False
-
     if is_heating == True:
         heat_string = ">H<"
     else:
@@ -113,4 +138,4 @@ while True:
 
     lcd.move_to(0, 0)
     lcd.putstr("ACT: {0:3.1f}".format(temp_curr) + chr(0) + "C  " + heat_string +
-               "\nTGT: {0:3.1f}".format(temp_tgt) + chr(0) + "C  " + system_on_string)
+               "\nTGT: {0:3.1f}".format(temp_tgt) + chr(0) + "C  " + system_on_string)
\ No newline at end of file