array(6) {
  ["version"]=>
  int(2)
  ["device_id"]=>
  int(2015)
  ["temperature_value"]=>
  float(20.031064968287)
  ["temperature_unit"]=>
  string(3) "°C"
  ["battery_voltage_value"]=>
  float(3.168)
  ["battery_voltage_unit"]=>
  string(1) "V"
}
array(4) {
  ["version"]=>
  int(2)
  ["device_id"]=>
  int(2015)
  ["battery_voltage_value"]=>
  float(3.168)
  ["battery_voltage_unit"]=>
  string(1) "V"
}