diff --git a/hmcon-setup.sh b/hmcon-setup.sh
index e680f4f..a23da32 100755
--- a/hmcon-setup.sh
+++ b/hmcon-setup.sh
@@ -119,12 +119,16 @@ rfd() {
                 case $opt in
                     "HM-MOD-RPI-PCB")
 # FIXME configure GPIO18, remove serial console
+#prepare additional string for rfd init script
 SetupGPIO="# export GPIO
 echo 18 > /sys/class/gpio/export
 echo out > /sys/class/gpio/gpio18/direction
 "
 # allow hmcon gpio access when using HM-MOD-RPI-PCB
 usermod -a -G gpio hmcon
+# give user a reminder
+echo '! you will need to disable the boot up and diagnostic output to the serial port: remove ttyAMA0 entries --> #sudo vi /boot/cmdline.txt'
+echo '! you will need to comment ttyAMA0 --> #sudo vi /etc/inittab delete or comment #T0:23:respawn:/sbin/getty -L ttyAMA0 115200 vt100'
 cat >> $ETC/rfd.conf <<- EOM
 [Interface $i]
 Type = CCU2