diff --git a/avr/modules/brightness/main.asm b/avr/modules/brightness/main.asm
index 4a0acb3..dea3fd6 100644
--- a/avr/modules/brightness/main.asm
+++ b/avr/modules/brightness/main.asm
@@ -88,16 +88,20 @@ Brightness_Every100ms:
   breq Brightness_Every100ms_startMeasure
   ret
 Brightness_Every100ms_startMeasure:
-  sbi ADCSRA, ADSC                     ; start conversion
+  inr r16, ADCSRA                      ; start conversion
+  sbr r16, (1<<ADSC)
+  outr ADCSRA, r16
+;  sbi ADCSRA, ADSC                     ; start conversion
   ret
 Brightness_Every100ms_readValue:
-  sbic ADCSRA, ADSC
+  inr r16, ADCSRA
+  sbrc r16, ADSC
     ret ; return if bit still set, leave brightnessTimer at "1"
   ; conversion complete, read value
   ldi r16, BRIGHTNESS_INTERVAL                 ; restart timer
   sts brightnessTimer, r16
-  in r16, ADCL
-  in r17, ADCH                                 ; read value from ADC
+  inr r16, ADCL
+  inr r17, ADCH                                 ; read value from ADC
   sts brightnessLastValue, r16
   sts brightnessLastValue+1, r17
   ; convert to 1/0