{
  "$comment": "Single source for signal identity. Topic name and envelope unit are both derived from these entries and are never authored separately. source=obd2 is standardised; source=host is the Orin itself (orin-status), not the car. source=z27ag is reverse-engineered from the car's own broadcast frames, and its 'can' block is the only place its layout is written down: id (11-bit, hex string), byte (first data byte, 0-7), length in bits (1, 8 or 16), bit (length 1 only: 0 = LSB of that byte), order (length 16: big = byte first is most significant, little = the reverse), scale and offset (value = raw * scale + offset; booleans are raw != 0). 'evidence' names the contracts report that found it.",
  "signals": {
    "engine_rpm": {
      "unit": "rpm",
      "type": "number",
      "source": "z27ag",
      "description": "Engine speed",
      "range": [
        0,
        8000
      ],
      "can": {
        "id": "0x210",
        "byte": 4,
        "length": 16,
        "order": "big",
        "scale": 1,
        "offset": 0,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "vehicle_speed_kph": {
      "unit": "kph",
      "type": "number",
      "source": "obd2",
      "description": "Road speed",
      "range": [
        0,
        255
      ]
    },
    "coolant_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "obd2",
      "description": "Engine coolant temperature",
      "range": [
        -40,
        215
      ]
    },
    "intake_air_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "obd2",
      "description": "Intake air temperature",
      "range": [
        -40,
        215
      ]
    },
    "throttle_pct": {
      "unit": "percent",
      "type": "number",
      "source": "obd2",
      "description": "Throttle position",
      "range": [
        0,
        100
      ]
    },
    "engine_load_pct": {
      "unit": "percent",
      "type": "number",
      "source": "obd2",
      "description": "Calculated engine load",
      "range": [
        0,
        100
      ]
    },
    "fuel_level_pct": {
      "unit": "percent",
      "type": "number",
      "source": "obd2",
      "description": "Fuel tank level",
      "range": [
        0,
        100
      ]
    },
    "intake_pressure_kpa": {
      "unit": "kpa",
      "type": "number",
      "source": "obd2",
      "description": "Intake manifold absolute pressure",
      "range": [
        0,
        255
      ]
    },
    "maf_gps": {
      "unit": "g/s",
      "type": "number",
      "source": "obd2",
      "description": "Mass air flow rate",
      "range": [
        0,
        656
      ]
    },
    "accel_pedal_pct": {
      "unit": "percent",
      "type": "number",
      "source": "z27ag",
      "description": "Accelerator pedal position (0x00 at rest, 0xFA flat)",
      "range": [
        0,
        100
      ],
      "can": {
        "id": "0x210",
        "byte": 0,
        "length": 8,
        "scale": 0.4,
        "offset": 0,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "brake_pedal": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Brake pedal switch: pressed",
      "can": {
        "id": "0x231",
        "byte": 4,
        "bit": 1,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "handbrake": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Handbrake applied",
      "can": {
        "id": "0x239",
        "byte": 0,
        "bit": 2,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "indicator_left": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Left indicator lamp, as it flashes (on and off at the flasher's rate)",
      "can": {
        "id": "0x423",
        "byte": 2,
        "bit": 6,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "indicator_right": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Right indicator lamp, as it flashes. Hazards were seen on the left bit only: open",
      "can": {
        "id": "0x423",
        "byte": 2,
        "bit": 5,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "side_lights": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Side (position) lights on; also on with dipped beam",
      "can": {
        "id": "0x423",
        "byte": 2,
        "bit": 2,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "dipped_beam": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Dipped headlights on",
      "can": {
        "id": "0x423",
        "byte": 3,
        "bit": 1,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "door_open": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Any door open",
      "can": {
        "id": "0x423",
        "byte": 2,
        "bit": 1,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "driver_door_open": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "Driver's door open",
      "can": {
        "id": "0x423",
        "byte": 0,
        "bit": 4,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "ac_compressor": {
      "unit": "",
      "type": "boolean",
      "source": "z27ag",
      "description": "A/C compressor engaged (engine running)",
      "can": {
        "id": "0x13D",
        "byte": 6,
        "bit": 7,
        "length": 1,
        "evidence": "Z27AG-DECODE-1"
      }
    },
    "orin_cpu_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "host",
      "description": "Orin CPU cluster temperature",
      "range": [
        -40,
        110
      ]
    },
    "orin_gpu_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "host",
      "description": "Orin GPU temperature",
      "range": [
        -40,
        110
      ]
    },
    "orin_soc_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "host",
      "description": "Orin SoC temperature, hottest of its sensors",
      "range": [
        -40,
        110
      ]
    },
    "orin_tj_temp_c": {
      "unit": "celsius",
      "type": "number",
      "source": "host",
      "description": "Orin junction temperature: the hottest point on the die, which throttling acts on",
      "range": [
        -40,
        110
      ]
    },
    "orin_cpu_pct": {
      "unit": "percent",
      "type": "number",
      "source": "host",
      "description": "CPU utilisation, all cores",
      "range": [
        0,
        100
      ]
    },
    "orin_gpu_pct": {
      "unit": "percent",
      "type": "number",
      "source": "host",
      "description": "GPU utilisation",
      "range": [
        0,
        100
      ]
    },
    "orin_ram_used_mb": {
      "unit": "MB",
      "type": "number",
      "source": "host",
      "description": "Memory in use, CPU and GPU together (one shared pool): total minus available",
      "range": [
        0,
        8192
      ]
    },
    "orin_ram_used_pct": {
      "unit": "percent",
      "type": "number",
      "source": "host",
      "description": "Memory in use as a share of the total",
      "range": [
        0,
        100
      ]
    },
    "orin_swap_used_mb": {
      "unit": "MB",
      "type": "number",
      "source": "host",
      "description": "Swap in use",
      "range": [
        0,
        16384
      ]
    },
    "orin_power_w": {
      "unit": "W",
      "type": "number",
      "source": "host",
      "description": "Orin module input power (VDD_IN), from the onboard INA3221",
      "range": [
        0,
        30
      ]
    },
    "orin_fan_rpm": {
      "unit": "rpm",
      "type": "number",
      "source": "host",
      "description": "Cooling fan speed",
      "range": [
        0,
        10000
      ]
    },
    "net_wifi_up": {
      "unit": "",
      "type": "boolean",
      "source": "host",
      "description": "WiFi associated and up"
    },
    "net_wifi_ssid": {
      "unit": "",
      "type": "string",
      "source": "host",
      "description": "Network name (SSID) of the WiFi the Orin is associated with; not sent while WiFi is down"
    },
    "net_wifi_signal_dbm": {
      "unit": "dBm",
      "type": "number",
      "source": "host",
      "description": "WiFi signal level",
      "range": [
        -100,
        0
      ]
    },
    "net_wifi_rx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "WiFi receive rate (into the Orin)",
      "range": [
        0,
        1000000
      ]
    },
    "net_wifi_tx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "WiFi transmit rate (out of the Orin)",
      "range": [
        0,
        1000000
      ]
    },
    "net_lte_state": {
      "unit": "",
      "type": "string",
      "source": "host",
      "description": "Modem state as ModemManager reports it (connected, registered, searching, disabled, …), or absent with no modem"
    },
    "net_lte_tech": {
      "unit": "",
      "type": "string",
      "source": "host",
      "description": "Access technology in use (lte, umts, …); empty when not registered"
    },
    "net_lte_signal_pct": {
      "unit": "percent",
      "type": "number",
      "source": "host",
      "description": "Modem signal quality",
      "range": [
        0,
        100
      ]
    },
    "net_lte_rx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "LTE receive rate (into the Orin)",
      "range": [
        0,
        150000
      ]
    },
    "net_lte_tx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "LTE transmit rate (out of the Orin)",
      "range": [
        0,
        50000
      ]
    },
    "net_tablet_up": {
      "unit": "",
      "type": "boolean",
      "source": "host",
      "description": "USB link to the tablet has carrier"
    },
    "net_tablet_rx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "USB tablet link, tablet to Orin",
      "range": [
        0,
        480000
      ]
    },
    "net_tablet_tx_kbps": {
      "unit": "kbit/s",
      "type": "number",
      "source": "host",
      "description": "USB tablet link, Orin to tablet",
      "range": [
        0,
        480000
      ]
    },
    "can_up": {
      "unit": "",
      "type": "boolean",
      "source": "host",
      "description": "The recorder's CAN interface (the PEAK, can_pcan) is present and up; false when absent or down"
    },
    "can_bus_state": {
      "unit": "",
      "type": "string",
      "source": "host",
      "description": "CAN controller state: ERROR-ACTIVE (normal), ERROR-WARNING, ERROR-PASSIVE, BUS-OFF, STOPPED (down), or absent with no adapter"
    },
    "can_rx_fps": {
      "unit": "frames/s",
      "type": "number",
      "source": "host",
      "description": "CAN frames received per second on that interface",
      "range": [
        0,
        10000
      ]
    },
    "ups_battery_v": {
      "unit": "V",
      "type": "number",
      "source": "host",
      "description": "UPS battery pack voltage (3S Li-ion, 9.0–12.6 V)",
      "range": [
        0,
        16
      ]
    },
    "ups_current_a": {
      "unit": "A",
      "type": "number",
      "source": "host",
      "description": "UPS battery current: positive charging, negative discharging",
      "range": [
        -5,
        5
      ]
    },
    "ups_battery_pct": {
      "unit": "percent",
      "type": "number",
      "source": "host",
      "description": "UPS charge estimate from cell voltage, corrected for load. An estimate, steadiest at rest",
      "range": [
        0,
        100
      ]
    },
    "ups_state": {
      "unit": "",
      "type": "string",
      "source": "host",
      "description": "charging, discharging (running on battery) or idle (on input power, not charging)"
    }
  }
}