diff --git a/avr/modules/tcrt1000/main2.asm b/avr/modules/tcrt1000/main2.asm
index ae6adbc..9f3090c 100644
--- a/avr/modules/tcrt1000/main2.asm
+++ b/avr/modules/tcrt1000/main2.asm
@@ -10,7 +10,8 @@
 
 
 .equ TCRT1K_INTERVAL          = 7
-.equ TCRT1K_LIMIT             = 170
+;.equ TCRT1K_LIMIT             = 170
+.equ TCRT1K_LIMIT             = 100
 
 .equ TCRT1K_FLAGS_VALID_BIT   = 7
 .equ TCRT1K_FLAGS_VALUE_BIT   = 0
@@ -24,6 +25,7 @@
 tcrt1kDataBegin:
   tcrt1kTimer:        .byte 1
   tcrt1kFlags:        .byte 1
+  tcrt1kLastValue:    .byte 1
 tcrt1kDataEnd:
 
 
@@ -96,24 +98,25 @@ TCRT1K_Every100ms_ledOn:
   sbi TCRT1K_LED_PORT, TCRT1K_LED_PIN ; LED on
   ret
 TCRT1K_Every100ms_startMeasure:
-  sbi ADCSRA, ADSC                    ; start conversion
+  sbi ADCSRA, ADSC                     ; start conversion
   ret
 TCRT1K_Every100ms_readValue:
   sbic ADCSRA, ADSC
     ret ; return if bit still set, leave tcrt1kTimer at "1"
   ; conversion complete, read value
-  ldi r16, TCRT1K_INTERVAL            ; restart timer
+  ldi r16, TCRT1K_INTERVAL             ; restart timer
   sts tcrt1kTimer, r16
-  in r16, ADCH                        ; read value from ADC
-  cbi TCRT1K_LED_PORT, TCRT1K_LED_PIN ; LED off
+  in r16, ADCH                         ; read value from ADC
+  sts tcrt1kLastValue, r16
+  cbi TCRT1K_LED_PORT, TCRT1K_LED_PIN  ; LED off
   ; convert to 1/0
   lds r17, tcrt1kFlags
-  cbr r17, (1<<TCRT1K_FLAGS_VALUE_BIT)
-  cpi r16, TCRT1K_LIMIT
-  brcs TCRT1K_Every100ms_valueSet
-  sbr r17, (1<<TCRT1K_FLAGS_VALUE_BIT)
+  cbr r17, (1<<TCRT1K_FLAGS_VALUE_BIT) ; clear value bit
+  cpi r16, TCRT1K_LIMIT                ; ADC value < LIMIT?
+  brcs TCRT1K_Every100ms_valueSet      ; yes: keep value bit zero
+  sbr r17, (1<<TCRT1K_FLAGS_VALUE_BIT) ; no: set value bit
 TCRT1K_Every100ms_valueSet:
-  sbr r17, (1<<TCRT1K_FLAGS_VALID_BIT)
+  sbr r17, (1<<TCRT1K_FLAGS_VALID_BIT) ; set valid bit
   sts tcrt1kFlags, r17
   ret
 ; @end