Merge pull request 'minor changes' (#1) from Ailuriya/femtosynth:master into master

Reviewed-on: #1

main.cpp

@@ -5,8 +5,9 @@
 
 int main() {
     const int sample_rate = 48000;
-    const float freq = 440.0f;
+    const float freq = 50.0f;
     float phase = 0.0f;
+    int duration = 1;
 
     PipeMini audio;
 
@@ -25,8 +26,8 @@ int main() {
         return 1;
     }
 
-    printf("playing 440 Hz sine for 5 seconds...\n");
-    sleep(5);
+    printf("playing %f Hz sine for %d seconds...\n", freq, duration);
+    sleep(duration);
 
     return 0;
 }