{
  "metadata": {
    "id": "adafruit-scd40-breakout",
    "name": "Adafruit SCD-40 – True CO₂, Temperature, and Humidity Sensor Breakout",
    "type": "sensor",
    "description": "Sensirion SCD40 photoacoustic NDIR CO₂ sensor on STEMMA QT/Qwiic breakout with on-board 3.3 V regulation and I2C level shifting. Measures CO₂, temperature, and humidity.",
    "manufacturer": "Adafruit",
    "part_number": "5187",
    "datasheet_url": "https://sensirion.com/media/documents/E0F04247/631EF271/CD_DS_SCD40_SCD41_Datasheet_D1.pdf",
    "tags": [
      "scd40",
      "co2",
      "ndir",
      "i2c",
      "0x62",
      "stemmaqt",
      "qwiic",
      "rht",
      "asc",
      "frc"
    ],
    "schema_version": "1.4.0",
    "version": "1.1.0",
    "taxonomy": [
      "sensor.environmental",
      "sensor.gas",
      "expansion.breakout"
    ]
  },
  "domains": [
    {
      "domain": "electrical",
      "power_domains": [
        {
          "id": "vin_3to5",
          "name": "VIN (3–5 V)",
          "nominal_voltage_V": 3.3,
          "voltage_range_V": [
            3,
            5
          ],
          "isolation_type": "non_isolated",
          "ground_reference": "common",
          "description": "Board input feeding on-board 3.3 V regulator and I2C level shifting"
        },
        {
          "id": "vdd_3v3_out",
          "name": "3Vo output",
          "nominal_voltage_V": 3.3,
          "voltage_range_V": [
            3.2,
            3.4
          ],
          "isolation_type": "non_isolated",
          "ground_reference": "common",
          "description": "Regulated 3.3 V output for light loads"
        }
      ],
      "resources": [
        {
          "id": "vin",
          "name": "VIN",
          "functions": [
            {
              "name": "power_in",
              "signal_class": "power"
            }
          ],
          "connector_type": "pin_header",
          "power_domain_id": "vin_3to5"
        },
        {
          "id": "gnd",
          "name": "GND",
          "functions": [
            {
              "name": "ground",
              "signal_class": "ground"
            }
          ],
          "connector_type": "pin_header",
          "power_domain_id": "vin_3to5"
        },
        {
          "id": "vout3v3",
          "name": "3Vo",
          "functions": [
            {
              "name": "power_out",
              "signal_class": "power"
            }
          ],
          "connector_type": "pin_header",
          "power_domain_id": "vdd_3v3_out"
        },
        {
          "id": "sda",
          "name": "SDA",
          "functions": [
            {
              "name": "i2c_sda",
              "signal_class": "data"
            }
          ],
          "connector_type": "pin_header"
        },
        {
          "id": "scl",
          "name": "SCL",
          "functions": [
            {
              "name": "i2c_scl",
              "signal_class": "clock"
            }
          ],
          "connector_type": "pin_header"
        },
        {
          "id": "stemmaqta",
          "name": "STEMMA QT A",
          "functions": [
            {
              "name": "i2c_sda",
              "signal_class": "data",
              "shareable_with": [
                "i2c_scl"
              ]
            },
            {
              "name": "i2c_scl",
              "signal_class": "clock",
              "shareable_with": [
                "i2c_sda"
              ]
            },
            {
              "name": "power_in",
              "signal_class": "power"
            },
            {
              "name": "ground",
              "signal_class": "ground"
            }
          ],
          "connector_type": "jst-sh",
          "power_domain_id": "vin_3to5",
          "description": "JST-SH 4-pin I2C"
        },
        {
          "id": "stemmaqtb",
          "name": "STEMMA QT B",
          "functions": [
            {
              "name": "i2c_sda",
              "signal_class": "data",
              "shareable_with": [
                "i2c_scl"
              ]
            },
            {
              "name": "i2c_scl",
              "signal_class": "clock",
              "shareable_with": [
                "i2c_sda"
              ]
            },
            {
              "name": "power_in",
              "signal_class": "power"
            },
            {
              "name": "ground",
              "signal_class": "ground"
            }
          ],
          "connector_type": "jst-sh",
          "power_domain_id": "vin_3to5",
          "description": "Second JST-SH 4-pin I2C (pass-through)"
        }
      ],
      "interfaces": [
        {
          "id": "i2c_target",
          "name": "I2C target interface",
          "protocol": {
            "type": "i2c",
            "role": "target"
          },
          "requires": [
            {
              "function": "i2c_sda",
              "count": 1,
              "shareable_with": [
                "i2c_scl"
              ]
            },
            {
              "function": "i2c_scl",
              "count": 1,
              "shareable_with": [
                "i2c_sda"
              ]
            }
          ],
          "timing": {
            "max_i2c_freq_hz": 100000
          },
          "description": "7-bit address 0x62 fixed"
        }
      ],
      "supply_voltage_V": [
        3,
        5
      ],
      "metadata": {
        "i2c_address_7bit": "0x62",
        "co2_range_ppm": [
          400,
          2000
        ],
        "co2_accuracy_ppm_plus_percent": {
          "offset_ppm": 50,
          "percent_of_reading": 5
        },
        "avg_current_mA_at_3v3": 15,
        "peak_current_mA_at_3v3": 205
      }
    },
    {
      "domain": "mechanical",
      "package_type": "PCB Module",
      "dimensions_mm": {
        "length": 25.5,
        "width": 22.8,
        "height": 7.7
      },
      "resources": [],
      "interfaces": []
    }
  ],
  "design_rules": [
    "Provide a low-ripple supply; design for ~205 mA peak current and <30 mVpp ripple at the sensor rail.",
    "Enable ASC for long-term operation with periodic exposure to ~400 ppm CO₂, or perform FRC using a known reference.",
    "Use low-power periodic mode if self-heating or power is a concern."
  ],
  "warnings": [
    "Non-condensing operation only; avoid solvents and adhesives that outgas into the sensing volume.",
    "I2C timing limited to 100 kHz per device spec; higher bus speeds may cause communication faults.",
    "Discard the first reading after power-up or wake as recommended by the vendor."
  ]
}