// This uses built-in ChucK Unit Generators to
// compute Zero Crossings, lots of monkey business :-)
// by Perry R. Cook, updated January 2014

adc => ZeroX z => HalfRect f => OnePole p => blackhole; // basic patch
0.0 => float myZeroes;          // This holds the last zero crossing count
    
spork ~ ZC(1.000);  
        
while (1)       {
    100.0 :: second => now;  // do other stuff here 
}
     
fun void ZC(float howoften)     {
    (howoften*44100) - 1 => float wait;
    while (1)   {
        wait :: samp => now;
        p.last() => myZeroes;
    <<< "Zero Crossings = ", myZeroes >>>;
        0.0 => p.a1;
        0.0 => p.b0;
        1 :: samp => now;
        -1.0 => p.a1;   // this is dangerous, but we
        1.0 => p.b0;    // know what we're doing
    }
}