change build script not to override i2c

build.sh

@@ -3,13 +3,15 @@ set -e
 
 function enable_i2c {
     if command -v raspi-config &> /dev/null; then
+    if [[ $(sudo raspi-config nonint get_i2c) -eq 1 ]] ; then
         echo "Enabling i2c"
         sudo modprobe i2c-dev
         sudo raspi-config nonint do_i2c 0
-        if [[ ! -z $(grep 'dtparam=i2c_arm=on$' /boot/config.txt) ]] ; then
-            echo "Setting the i2c clock speed to 400 kHz, you will have to reboot for this to take effect."
-            sudo sed -i -e 's/dtparam=i2c_arm=on$/dtparam=i2c_arm=on,i2c_arm_baudrate=400000/g' /boot/config.txt
-        fi
+    fi
+    if [[ $(grep -c '^dtparam=i2c_arm=on$' /boot/config.txt) -ge 1 ]] ; then
+        echo "Setting the i2c clock speed to 400 kHz, you will have to reboot for this to take effect."
+        sudo sed -i -e 's/dtparam=i2c_arm=on$/dtparam=i2c_arm=on,i2c_arm_baudrate=400000/g' /boot/config.txt
+    fi
     else
 		echo "Can not automatically enable i2c you might have to do this manually"
 	fi