diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index c5b8fc1..364e8ef 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,8 +1,10 @@
 Added RTC (https://www.adafruit.com/product/3013)
+    added packages python3-smbus i2c-tools to installer
+    updated installer to set gpio baud to 921600
 NEO GPS Module
     Wiring
         Changed to 5v mode
     U-Center-2 (https://www.u-blox.com/en/u-center-2)
         Changed Baudrate UART1 to 921600
         Time Pulse Mode
-            Antenna Cable Delay set to the calculated 14ns
\ No newline at end of file
+            Antenna Cable Delay set to the calculated 14ns
diff --git a/installer3.sh b/installer3.sh
index ceef6be..d3c47b2 100644
--- a/installer3.sh
+++ b/installer3.sh
@@ -42,7 +42,7 @@ sudo apt purge -y "bluetooth*" "usb*" "wireless*" "pci*" "fonts*" build-essentia
 
 # install da packages
 echo "Installing packages, this may take a while..."
-sudo apt install -y telegraf grafana influxdb pps-tools gpsd gpsd-clients chrony syslog-ng gh lynx btop htop iptraf iotop neovim netcat-traditional
+sudo apt install -y telegraf grafana influxdb pps-tools gpsd gpsd-clients chrony syslog-ng gh lynx btop htop iptraf iotop neovim netcat-traditional python3-smbus i2c-tools
 
 # check if /boot/firmware/config.txt is configured yet
 grep -q -e "GPS PPS signals" /boot/firmware/config.txt
@@ -52,11 +52,17 @@ grepconfig=$?
 if [ $grepconfig -eq 0 ]; then
     echo "/boot/firmware/config.txt already updated, skipping..."
 else
+    # pps and gpio uart
     echo "Adding lines to /boot/firmware/config.txt to enable pps and gpio uart..."
-    sudo bash -c "echo '# the next 3 lines are for GPS PPS signals' >> /boot/firmware/config.txt"
-    sudo bash -c "echo 'dtoverlay=pps-gpio,gpiopin=18' >> /boot/firmware/config.txt"
-    sudo bash -c "echo 'enable_uart=1' >> /boot/firmware/config.txt"
+    sudo bash -c "echo '# GPS PPS GPIO Signal' >> /boot/firmware/config.txt"
+    sudo bash -c "echo 'dtoverlay=pps-gpio,gpiopin=18' >> /boot/firmware/config.txt" # pps
+    
+    sudo bash -c "echo '# GPS GPIO UART' >> /boot/firmware/config.txt"
+    sudo bash -c "echo 'enable_uart=1' >> /boot/firmware/config.txt" # enable uart
     sudo bash -c "echo 'init_uart_baud=921600' >> /boot/firmware/config.txt" # set baudrate here to
+    # i2c
+    sudo bash -c "echo '# I2C Hardware RTC Overlay' >> /boot/firmware/config.txt"
+    sudo bash -c "echo 'dtoverlay=i2c-rtc,ds3231' >> /boot/firmware/config.txt"
 fi
 
 # check if pps-gpio is in /etc/modules already
diff --git a/notes-scratch-todo.txt b/notes-scratch-todo.txt
index 88e80e6..e6cd177 100644
--- a/notes-scratch-todo.txt
+++ b/notes-scratch-todo.txt
@@ -2,6 +2,18 @@ rtc module
     ds3231
         product page: https://www.adafruit.com/product/3013
         product tutorial: https://learn.adafruit.com/adafruit-ds3231-precision-rtc-breakout/overview
+            install packages python3-smbus i2c-tools
+            enable i2c support in raspi-config
+                interfacing options->i2c->
+                    enable <Yes>
+                    kernel module loaded by default <Yes>
+            check that i2c-dev is in /etc/modules
+            add `dtoverlay=i2c-rtc,ds3231` to /boot/firmware/config.txt
+            reboot
+            detect/test module `sudo i2cdetect -y 1`
+                looking for address 68
+            
+
         raspberry pi RTC tutorial: https://learn.adafruit.com/adding-a-real-time-clock-to-raspberry-pi/set-rtc-time
         pinout: https://learn.adafruit.com/adafruit-ds3231-precision-rtc-breakout/pinouts
         battery:  CR1220