Dixi,
Check out my post for the answer here: Help needed with running local server at start-up, Rasp Pi 3
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Here is my cheat sheet, hopefully it will help:
HOW TO CONFIGURE BLYNK LOCAL SERVER:
1 - Login to Raspberry Pi
2- Open Terminal
3- Install Java8
sudo apt-get install oracle-java8-jdk
4- Check Java version
java -version
5- Create Blynk directory
Mkdir Blynk
6- Change directory from root “pi” to “Blynk” directory
cd Blynk
7- Download Blynk server file package
wget “https://github.com/blynkkk/blynk-server/releases/download/v0.39.4/server-0.39.4-java8.jar”
8- Manual start Blynk server
java -jar server-0.39.4-java8.jar -dataFolder /home/pi/Blynk
9- At this point, the Blynk Server successfully started. Take a note on login ID and password for the web portal. To get out of this terminal windows, press CTRL+C
10- Enable Blynk server auto start each time power failure or hardware reboot
a. Open Terminal and type: sudo leafpad
b. Browse to FileSystem\etc\rc.local then add this line as below then save it.
java -jar /home/pi/Blynk/server-0.39.4-java8.jar -dataFolder /home/pi/Blynk &
c. At the Terminal, type: crontab –e
d. Add the following line then save it.
@reboot java -jar /home/pi/Blynk/server-0.39.4-java8.jar -dataFolder /home/pi/Blynk &
e. Reboot the server then Blynk should automatically start