Drobo Status is a python program that will connect to your Drobo and return JSON data regarding your Drobo

[drobo]
host = IP of your DROBO

{"name":"Storage", "serial": "0db1135c014012","firmware-version": "2.1.8 [7.38.12635]","disk-total": "12 TB","disk-used": "1 TB","disk-free": "10 TB", "drives": [{"sid": 0, "status": 3, "capacity": "2.73 TB"}, {"sid": 1, "status": 3, "capacity": "2.73 TB"}, {"sid": 2, "status": 3, "capacity": "2.73 TB"}, {"sid": 3, "status": 3, "capacity": "2.73 TB"}, {"sid": 4, "status": 3, "capacity": "2.73 TB"}, {"sid": 5, "status": 3, "capacity": "2.73 TB"}, {"sid": 6, "status": 3, "capacity": "2.73 TB"}, {"sid": 7, "status": 129, "capacity": "0 B"}]}

platform: rest
    name: tfam-storage
    # This is the ip of the host running drobo-status.py
    resource: http://192.168.1.126:5000
    json_attributes:
      - name
      - serial
      - firmware
      - disk-total
      - disk-used
      - disk-free
    value_template: "OK"
  - platform: template
    sensors:
      storage_name:
        value_template: "{{ state_attr('sensor.tfam-storage', 'name')['name'] }}"
      storage_serial:
        value_template: "{{ state_attr('sensor.tfam-storage', 'serial')['serial'] }}"
      storage_firmware:
        value_template: "{{ state_attr('sensor.tfam-storage', 'firmware')['firmware'] }}"
      storage_disk_total:
        value_template: "{{ state_attr('sensor.tfam-storage', 'disk-total')['disk-total'] }}"