0. Builde driver
```
make modules
make tty-battery
```

1. Install driver
```
    mkdir -p /lib/modules/`uname -r`/extra
    cp battery_drv.ko /lib/modules/`uname -r`/extra
    depmod -a
    echo battery_drv >> /etc/modules
    modprobe battery_drv
```

2. Install service
```
    cp tty-battery /usr/bin/
    chmod 0755 /usr/bin/tty-battery
    cp ttybattery.service /etc/systemd/system
    chmod 0644 /etc/systemd/system/ttybattery.service
    systemctl enable ttybattery
    systemctl start ttybattery
    systemctl status ttybattery
```