minor changes

main.cpp

@@ -5,7 +5,7 @@
 
 int main() {
     const int sample_rate = 48000;
-    const float freq = 440.0f;
+    const float freq = 50.0f;
     float phase = 0.0f;
 
     PipeMini audio;
@@ -25,8 +25,8 @@ int main() {
         return 1;
     }
 
-    printf("playing 440 Hz sine for 5 seconds...\n");
+    printf("playing %f Hz sine for 5 seconds...\n", freq);
-    sleep(5);
+    sleep(1);
 
     return 0;
 }