Detect butten press by level rather than change

This fixes a problem that would cause it to immediately advance
waveforms on startup specifically after being programmed.

diff --git a/siggen.asm b/siggen.asm
index 5661faacdf759109d54300b15bdd8afcc899bb5b..580949b708f6885873c5df51a5b5541946d79d80 100644 (file)
--- a/siggen.asm
+++ b/siggen.asm
@@ -320,8 +320,8 @@ _adc_wait:
        ; --------------------------------------------------------------
        ; ----- Poll for button presses and swap waveforms
 
-       ; Test for pin change interrupt flag
-       sbis    PCIFR, PCIF1
+       ; Test for pushbutton pin pulled low
+       sbic    PINC, PINC5
        rjmp    _button_done
        ; Button pin status has changed