diff --git a/software/firmware/energy-montior/README.md b/software/firmware/energy-montior/README.md
index 532b88a..ba0ece2 100644
--- a/software/firmware/energy-montior/README.md
+++ b/software/firmware/energy-montior/README.md
@@ -35,6 +35,9 @@ Make sure the clamp is *always positioned towards the consumer*, otherwise it do
 
 ![point the clamp](./docs/images/clamp2.jpeg "point the clamp")
 
+Attention: I could not measure any meaningful values on the "cable". I had to go to the wire.
+![cable](./docs/images/clamp3.jpeg "use the clamp on the wire, not on the cable")
+
 ### Breadboard
 
 Let's start with a simple breadboard layout.
diff --git a/software/firmware/energy-montior/docs/images/clamp3.jpeg b/software/firmware/energy-montior/docs/images/clamp3.jpeg
new file mode 100644
index 0000000..cd0295e
Binary files /dev/null and b/software/firmware/energy-montior/docs/images/clamp3.jpeg differ