diff --git a/dev/build.sh b/dev/build.sh
index 7dc4702..128db8b 100755
--- a/dev/build.sh
+++ b/dev/build.sh
@@ -1,47 +1,100 @@
 #! /bin/bash
 
-mkdir -p /opt/ttn-gateway/dev
-cd /opt/ttn-gateway/dev
-git clone git://git.drogon.net/wiringPi
-cd wiringPi
+INSTALL_DIR="/opt/ttn-gateway"
+
+mkdir -p $INSTALL_DIR/dev
+cd $INSTALL_DIR/dev
+
+if [ ! -d wiringPi ]; then
+    git clone git://git.drogon.net/wiringPi
+    cd wiringPi
+else
+    cd wiringPi
+    git reset --hard
+    git pull
+fi
+./build
 cd ..
-git clone https://github.com/kersing/lora_gateway.git
-git clone https://github.com/kersing/paho.mqtt.embedded-c.git
-git clone https://github.com/kersing/ttn-gateway-connector.git
-git clone https://github.com/kersing/protobuf-c.git
-git clone https://github.com/kersing/packet_forwarder.git
-git clone https://github.com/google/protobuf.git
 
-apt update
-apt install protobuf-compiler
-apt install libprotobuf-dev
-apt install libprotoc-dev
-apt install automake
-apt install libtool
-apt install autoconf
+if [ ! -d lora_gateway ]; then
+    git clone https://github.com/kersing/lora_gateway.git
+else
+    cd lora_gateway
+    git reset --hard
+    git pull
+    cd ..
+fi
 
-cd lora_gateway/libloragw
+if [ ! -d paho.mqtt.embedded-c ]; then
+    git clone https://github.com/kersing/paho.mqtt.embedded-c.git
+else
+    cd paho.mqtt.embedded-c
+    git reset --hard
+    git pull
+    cd ..
+fi
+
+if [ ! -d ttn-gateway-connector ]; then
+    git clone https://github.com/kersing/ttn-gateway-connector.git
+else
+    cd ttn-gateway-connector
+    git reset --hard
+    git pull
+    cd ..
+fi
+
+if [ ! -d protobuf-c ]; then
+    git clone https://github.com/kersing/protobuf-c.git
+else
+    cd protobuf-c
+    git reset --hard
+    git pull
+    cd ..
+fi
+
+if [ ! -d packet_forwarder ]; then
+    git clone https://github.com/kersing/packet_forwarder.git
+else
+    cd packet_forwarder
+    git reset --hard
+    git pull
+    cd ..
+fi
+
+if [ ! -d protobuf ]; then
+    git clone https://github.com/google/protobuf.git
+else
+    cd protobuf
+    git reset --hard
+    git pull
+    cd ..
+fi
+
+apt-get update
+apt-get -y install protobuf-compiler libprotobuf-dev libprotoc-dev automake libtool autoconf
+
+cd $INSTALL_DIR/dev/lora_gateway/libloragw
 sed -i -e 's/PLATFORM= .*$/PLATFORM= imst_rpi/g' library.cfg
 sed -i -e 's/CFG_SPI= .*$/CFG_SPI= native/g' library.cfg
 make
 
-cd ../../protobuf-c
+cd $INSTALL_DIR/dev/protobuf-c
 ./autogen.sh
 ./configure
 make protobuf-c/libprotobuf-c.la
 mkdir bin
 ./libtool install /usr/bin/install -c protobuf-c/libprotobuf-c.la `pwd`/bin
 
-cd ../paho.mqtt.embedded-c/
+cd $INSTALL_DIR/dev/paho.mqtt.embedded-c/
 make
 make install
 
-cd ../ttn-gateway-connector
+cd $INSTALL_DIR/dev/ttn-gateway-connector
 cp config.mk.in config.mk
 make
 cp bin/libttn-gateway-connector.so /usr/lib/
 
-cd ../packet_forwarder/mp_pkt_fwd/
+cd $INSTALL_DIR/dev/packet_forwarder/mp_pkt_fwd/
 make
 
 echo "Build & Installation Completed."