1 files changed, 16 insertions, 0 deletions
diff --git a/guile/starlet/effects.scm b/guile/starlet/effects.scm
new file mode 100644
index 0000000..d908a52
--- /dev/null
+++ b/guile/starlet/effects.scm
@@ -0,0 +1,16 @@
+(define-module (starlet effects)
+  #:use-module (starlet base)
+  #:export (flash))
+
+
+(define pi (* 2 (acos 0)))
+
+(define (square-wave time hz)
+  (if (> (sin (* 2 pi hz time))
+         0)
+      100
+      0))
+
+(define (flash hz)
+  (lambda (time)
+    (square-wave time hz)))