diff --git a/avr/devices/c03/defs.asm b/avr/devices/c03/defs.asm
index 8649893..ac4a224 100644
--- a/avr/devices/c03/defs.asm
+++ b/avr/devices/c03/defs.asm
@@ -16,7 +16,7 @@
 ;                        DC  PB1  2     39 PA1 DEV1
 ;                      INT2  PB2  3     38 PA2 DEV2
 ;                    DSPRES  PB3  4     37 PA3 PA3
-;                        SS  PB4  5     36 PA4 PA4
+;                        SS  PB4  5     36 PA4 LUM
 ;                      MOSI  PB5  6     35 PA5
 ;                      MISO  PB6  7     34 PA6
 ;                       SCK  PB7  8     33 PA7
@@ -223,3 +223,13 @@
 ;.equ UDRIE0 = UDRIE
 
 
+; ---------------------------------------------------------------------------
+; Brightness
+
+
+.equ BRIGHTNESS_ADC_PORT    = PORTA ; adc4
+.equ BRIGHTNESS_ADC_DDR     = DDRA
+.equ BRIGHTNESS_ADC_PIN     = PORTA4
+.equ BRIGHTNESS_ADC_MUX     = 4
+
+
diff --git a/avr/modules/brightness/main.asm b/avr/modules/brightness/main.asm
index 2ef0eab..4a0acb3 100644
--- a/avr/modules/brightness/main.asm
+++ b/avr/modules/brightness/main.asm
@@ -55,11 +55,11 @@ Brightness_Init:
   cbi BRIGHTNESS_ADC_DDR, BRIGHTNESS_ADC_PIN                 ; set ADC port as input
 
   ldi r16, BRIGHTNESS_ADC_MUX                                ; select input pin, use Vcc as reference voltage
-  out ADMUX, r16
+  outr ADMUX, r16
   ldi r16, (0 << ADLAR)
-  out ADCSRB, r16
+  outr ADCSRB, r16
   ldi r16, (1 << ADEN) | (1 << ADPS1) | (1 << ADPS0)         ; enable, prescaler 8
-  out ADCSRA, r16
+  outr ADCSRA, r16
   
   ldi r16, BRIGHTNESS_INTERVAL
   sts brightnessTimer, r16