diff --git a/keypad/README.md b/keypad/README.md
index 8a35667..2560b98 100644
--- a/keypad/README.md
+++ b/keypad/README.md
@@ -5,3 +5,8 @@
 3) if re-making the hw from scratch, you need to make some HW mods to the keypad:
 	- green led moved to a different pin (due to UART conflict)
 4) verify the pin IDs
+
+Clock external 4 mhz
+Board: ATmega168
+Variant: 168/168A
+avrdude -p atmega168 -c usbasp -v -B 4 -U lfuse:w:0xed:m -U hfuse:w:0xdd:m -U efuse:w:0xf9:m