==== Red Spring Remote Controller ====
  * Raspberry Pi v2
  * NooElec NESDR Nano 2+ Tiny RTL-SDR
  * IEEE802.3af PoE 48V to 5V (2.4A) Micro USB adapter
  * [[https://www.waveshare.com/wiki/RPi_Relay_Board|Waveshare PRi Relay Board]]

==== BCM2835 ====
   > wget http://www.airspayce.com/mikem/bcm2835/bcm2835-1.68.tar.gz
   > tar zxvf bcm2835-1.68.tar.gz
   > cd bcm2835-1.68/
   > sudo ./configure && sudo make && sudo make check && sudo make install
   > cd ~

==== wiringPi ====
   > git clone https://github.com/WiringPi/WiringPi
   > cd WiringPi
   > ./build
   > gpio -v

==== Demo ====
   > wget https://www.waveshare.com/w/upload/0/0c/RPi_Relay_Board.zip
   > unzip -o RPi_Relay_Board.zip -d ./RPi_Relay_Board
   > sudo chmod 777 -R RPi_Relay_Board
   > cd RPi_Relay_Board
   > cd shell
   > sudo ./Relay.sh CH1 ON
   > sudo ./Relay.sh CH1 OFF
   > cd ..
   > cd bcm2835
   > make
   > sudo ./Relay_Module
   > cd ..
   > cd wiringPi
   > make
   > sudo ./Relay_Module
   > cd ..
   > cd python
   > sudo python Relay_Module.py




==== rtl-sdr ====
   > sudo apt-get install -y  cmake pkg-config libusb-1.0
   > sudo apt-get install git
   > git clone git://git.osmocom.org/rtl-sdr.git
   > cd rtl-sdr/
   > mkdir build
   > cd build
   > cmake ../ -DINSTALL_UDEV_RULES=ON
   > make
   > sudo make install
   > sudo ldconfig

Edit /etc/modprobe.d/raspi-blacklist.conf
     blacklist dvb_usb_rtl28xxu
     blacklist rtl2832
     blacklist rtl2830

Edit /etc/rc.local
   sleep 10
   _IP=$(hostname -I) || true
   if [“$_IP”]; then
   printf”My IP address is %s\n” “$_IP”
   /usr/local/bin/rtl_tcp -a $_IP &
   fi
   exit 0

Create firewall service for rtl_tcp
   > sudo nano /etc/firewalld/services/rtl_tcp.xml
      <?xml version="1.0" encoding="utf-8"?>
      <service>  
         <short>rtl_tcp</short>  
         <description>rtl_tcp</description>  
         <port protocol="tcp" port="1234"/>  
     </service>
   > sudo chmod 640 /etc/firewalld/services/rtl_tcp.xml
   > sudo firewall-cmd --permanent --add-service=rtl_tcp
   
 Create firewall service for MQTT
   > sudo nano /etc/firewalld/services/mqtt.xml
      <?xml version="1.0" encoding="utf-8"?>
      <service>  
         <short>mqtt</short>  
         <description>mqtt</description>  
         <port protocol="tcp" port="1883"/>  
         <port protocol="tcp" port="8883"/>  
     </service>
   > sudo chmod 640 /etc/firewalld/services/mqtt.xml
   > sudo firewall-cmd --permanent --add-service=mqtt