Here is my script. After every boot the service is active with no errors.
Description=Bluetooth on Startup
I had problems with the script itself and after that with the service due to the problems with the script:
rfkill unblock bluetooth hciconfig hci0 piscan hciconfig hci0 up
I did the next thing and it seems that is working now:
rfkill unblock bluetooth sleep 1 hciconfig hci0 piscan hciconfig hci0 up
Try this and let me know if it works for you.
I'm glad that it have worked. With the sleep command you are giving some time to the board to unblock the process, this is because after you enter the command it will take some time to be done so if you use hciconfig hci0 up and the bluetooth is still blocked you can have problems.
With the sleep command you will get the delay needed, this command work in seconds, take a look at the manual of this command: sleep(1) - Linux manual page