diff --git a/firmware/cup.c b/firmware/cup.c
index 7a4eb6a..c58fafd 100644
--- a/firmware/cup.c
+++ b/firmware/cup.c
@@ -146,6 +146,12 @@ void led_set(uint16_t value)
 	OCR0A = OCR0B = led_color = value >> 8;
 }
 
+void led_off(void)
+{
+	OCR0A = 0;
+	OCR0B = 255;
+}
+
 void adc_init(void)
 {
 	ADMUX = (1 << REFS1) | (TEMP_PIN << MUX0);/* Vref = 1.1, pin selection */
@@ -195,7 +201,8 @@ int main(void)
 			}
 		}
 		
-		if(setting_timeout) {led_set(target);}
+		if(!dev_state) {led_off();}
+		else if(setting_timeout) {led_set(target);}
 		else {led_set(temperature);}
 	}