diff --git a/tests/photo_interrupters.scad b/tests/photo_interrupters.scad
new file mode 100644
index 0000000..ee64fd6
--- /dev/null
+++ b/tests/photo_interrupters.scad
@@ -0,0 +1,28 @@
+//
+// NopSCADlib Copyright Chris Palmer 2018
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+include <../utils/core/core.scad>
+include <../vitamins/photo_interrupters.scad>
+
+use <../utils/layout.scad>
+
+module photo_interrupters()
+    layout([for(l = photo_interrupters) pi_base_length(l)], 5)
+        photo_interrupter(photo_interrupters[$i]);
+
+photo_interrupters();
diff --git a/vitamins/photo_interrupter.scad b/vitamins/photo_interrupter.scad
index 6838698..f7c7697 100644
--- a/vitamins/photo_interrupter.scad
+++ b/vitamins/photo_interrupter.scad
@@ -82,6 +82,3 @@ module pi_cutout(type) {
     translate([-pi_base_width(type)/2, pi_gap_width(type)/2, 0])
         cube([pi_base_width(type), pi_stem_width(type), pi_gap_height(type) + pi_base_height(type)]);
 };
-
-PH1 = ["PH1: Photo interrupter", 6.4, 25.9 , 3.5, 8.6, 4.1, 5.9, 3, "black", [22, 20, 1.6, true, 11-3.2, 0, "blue",[[8.3, -7.5], [8.3, 7.5]], 3]];
-photo_interrupter(PH1);
diff --git a/vitamins/photo_interrupters.scad b/vitamins/photo_interrupters.scad
index 6bb8015..6c92215 100644
--- a/vitamins/photo_interrupters.scad
+++ b/vitamins/photo_interrupters.scad
@@ -1 +1,5 @@
-PH1 = ["PH1: Photo interrupter", 6.4, 25.9 , 3.5, 8.6, 4.1, 5.9, 3, "black", [22, 20, 1.6, true, 11-3.2, 0, "blue",[[8.3, -7.5], [8.3, 7.5]], 3]];
\ No newline at end of file
+PH1 = ["PH1: Photo interrupter", 6.4, 25.9 , 3.5, 8.6, 4.1, 5.9, 3, "black", [22, 20, 1.6, true, 11-3.2, 0, "blue",[[8.3, -7.5], [8.3, 7.5]], 3]];
+
+photo_interrupters = [PH1];
+
+use <photo_interrupter.scad>