diff --git a/hardware/CHANGES.txt b/hardware/CHANGES.txt
index 9d5730a..817549e 100644
--- a/hardware/CHANGES.txt
+++ b/hardware/CHANGES.txt
@@ -1,3 +1,5 @@
 version 1 (2019-11-17):
-- first finished schenatic and layout
+- first finished schematic and layout
 - prototype board ordered
+- the button footprint is wrong. to fix it, cut the top left lead to break the connection to ground, and solder on of the bottom lead to the surrounding ground.
+- in the schematic I switched SDA and SCL to the I²C LCD backpack. to fix it, I soldered two coated wires through the pin holes of the backpack and crossed soldered them.