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CHESTER Scale

This article describes the core functionality, hardware description, and example JSON message of the catalog application CHESTER Scale.

caution

Some of the basics are not provided, as they are common for all CHESTER catalog applications. Please see:

Application Overview​

CHESTER Scale is designed for wireless weight measurement using load cells. The application supports connecting multiple weight probes (up to 4 channels) and provides real-time weight data transmission via NB-IoT/LTE-M or LoRaWAN networks.

The device is ideal for:

  • Industrial storage tank monitoring - Track fill levels of tanks, silos, or containers
  • Pallet and goods tracking - Monitor weight changes in logistics and warehousing
  • Livestock weight monitoring - Optimize feeding schedules and track animal health
  • Agricultural applications - Beehive monitoring, feed storage, etc.

Application Variants​

CHESTER Scale can be ordered in one of these variants:

CHESTER Scale​

The catalog application CHESTER Scale measures weight from up to 4 load cell channels.

The hardware of this application consists of the following ordering codes:

  • CHESTER-M-BCGLS - Standard mainboard
  • CHESTER-X3C:A or CHESTER-X3C:B - Load cell interface (2 channels per module)
  • CHESTER-E2-LP - Enclosure with SMA pigtail

See Ordering Codes for more details.

Firmware build shield options: ctr_lrw ctr_lte ctr_x3_a or ctr_lrw ctr_lte ctr_x3_b

CHESTER Scale Z​

The catalog application CHESTER Scale Z includes backup battery support for uninterrupted operation.

The hardware of this application consists of the following ordering codes:

  • CHESTER-M-BCGLS - Standard mainboard
  • CHESTER-Z1 - Backup module
  • CHESTER-X3C:A or CHESTER-X3C:B - Load cell interface (2 channels per module)
  • CHESTER-E2-LP - Enclosure with SMA pigtail

See Ordering Codes for more details.

Firmware build shield options: ctr_lrw ctr_lte ctr_x3_a ctr_z or ctr_lrw ctr_lte ctr_x3_b ctr_z

Measurement and Behavior​

Weight Measurement​

  • Weight sensors are sampled with a configurable period (parameter interval-sample).
  • Samples are then aggregated in the configurable interval (parameter interval-aggreg). Minimum, maximum, average, and median are computed from buffered samples for each channel.
  • Each aggregated value has its timestamp and are sent in a batch in a report interval period (parameter interval-report).
  • The weight-measurement-interval parameter controls how often the weight measurement cycle runs.

Channel Configuration​

The application supports up to 4 weight measurement channels:

  • Channel A1 and Channel A2 on slot A
  • Channel B1 and Channel B2 on slot B

Each channel can be individually enabled or disabled.

Backup (CHESTER Scale Z)​

CHESTER Scale Z (equipped with CHESTER-Z1) can also report information on the backup battery and external DC power state.

  • The current battery voltage and external DC voltage are sent in every report.
  • When the DC power input changes, the timestamp of the change event is stored altogether with the connected/disconnected state, this information is buffered, and the buffer of the events is sent (at the latest) with the regular report.
  • Optionally, DC power input changes can be reported immediately or with a configurable delay (parameter event-report-delay).
  • The maximum number of reports per hour is configurable (parameter event-report-rate).

Default Configuration​

This is the default configuration (printed using the app config show command):

app config interval-report 900
app config interval-sample 60
app config interval-aggreg 300
app config weight-measurement-interval 60
app config channel-a1-active true
app config channel-a2-active true
app config channel-b1-active true
app config channel-b2-active true

When equipped with backup (CHESTER-Z1):

app config event-report-delay 1
app config event-report-rate 30
app config backup-report-connected true
app config backup-report-disconnected true

Specific Commands​

info

You can easily explore the whole command tree structure - start with the help command.

caution

To apply a new configuration, you need to call config save, which applies the new configuration parameters and reboots the device.

Reporting​

Command to set report interval in seconds:

app config interval-report <30-86400>

Sampling and Aggregation​

Command to set sample interval in seconds:

app config interval-sample <1-86400>

Command to set aggregate interval in seconds:

app config interval-aggreg <1-86400>

Command to set weight measurement interval in seconds:

app config weight-measurement-interval <30-86400>

Channel Activation​

Command to enable/disable channel A1:

app config channel-a1-active <true/false>

Command to enable/disable channel A2:

app config channel-a2-active <true/false>

Command to enable/disable channel B1:

app config channel-b1-active <true/false>

Command to enable/disable channel B2:

app config channel-b2-active <true/false>

Backup (CHESTER-Z1)​

Command to set event report delay in seconds:

app config event-report-delay <1-86400>

Command to set event report rate in reports per hour:

app config event-report-rate <1-3600>

Command to enable/disable reporting when backup is connected:

app config backup-report-connected <true/false>

Command to enable/disable reporting when backup is disconnected:

app config backup-report-disconnected <true/false>

Firmware​

The latest firmware is available in the Catalog Applications Firmware chapter.

Example JSON Message​

{
  "message": {
    "version": 1,
    "sequence": 1,
    "timestamp": 1673272805
  },
  "attribute": {
    "vendor_name": "HARDWARIO",
    "product_name": "CHESTER-M",
    "hw_variant": "CGLS",
    "hw_revision": "R3.4",
    "fw_name": "CHESTER Scale",
    "fw_version": "v3.0.0",
    "serial_number": "2159018267"
  },
  "system": {
    "uptime": 3600,
    "voltage_rest": 3.7,
    "voltage_load": 3.65,
    "current_load": 36
  },
  "backup": {
    "line_voltage": 24.01,
    "batt_voltage": 4.09,
    "state": "connected",
    "events": []
  },
  "network": {
    "imei": 351358815180770,
    "imsi": 901288910018982,
    "parameter": {
      "eest": 7,
      "ecl": 0,
      "rsrp": -90,
      "rsrq": -8,
      "snr": 9,
      "plmn": 23003,
      "cid": 939040,
      "band": 20,
      "earfcn": 6447
    }
  },
  "thermometer": {
    "temperature": 22.18
  },
  "accelerometer": {
    "accel_x": 0.07,
    "accel_y": -0.16,
    "accel_z": 9.65,
    "orientation": 2
  },
  "weight": {
    "measurements": [
      {
        "timestamp": 1673272500,
        "raw_result_a1": 125430,
        "raw_result_a2": 98210,
        "raw_result_b1": 112340,
        "raw_result_b2": 87650
      },
      {
        "timestamp": 1673272560,
        "raw_result_a1": 125445,
        "raw_result_a2": 98225,
        "raw_result_b1": 112355,
        "raw_result_b2": 87660
      },
      {
        "timestamp": 1673272620,
        "raw_result_a1": 125420,
        "raw_result_a2": 98200,
        "raw_result_b1": 112330,
        "raw_result_b2": 87640
      }
    ]
  },
  "ble_tags": [
    {
      "addr": "1234567890AB",
      "rssi": -81,
      "voltage": 3.11,
      "humidity": {
        "measurements": [
          {
            "timestamp": 1673272500,
            "min": 54.78,
            "max": 55.31,
            "avg": 55.1,
            "mdn": 55.12
          }
        ]
      },
      "temperature": {
        "measurements": [
          {
            "timestamp": 1673272500,
            "min": 22.18,
            "max": 22.25,
            "avg": 22.23,
            "mdn": 22.25
          }
        ]
      }
    }
  ]
}

BLE Tag Subsystem​

info

CHESTER Scale also supports integration with Bluetooth tags (Teltonika EYE Sensor subsystem) for wireless temperature and humidity monitoring. Learn how to activate and configure this feature in the CHESTER BLE Tag Subsystem documentation.