Query Messages

Our firmware supports a set of remote commands, known as query messages, that allow you to interact with your device by sending APRS messages. You can check the device’s status, get metrics, or perform administrative actions like rebooting or initiating a firmware update.

To use these commands, send an APRS message to your device’s callsign with the command in the message body. For example, to get the firmware version, send a message to your station callsign with the text ?APRSV.

The system distinguishes between public commands, available to anyone, and administrative commands, which can only be executed by callsigns defined in the device’s admin list.

Public Commands

These commands can be sent by any station and are used for retrieving general status information.

  1. ?APRS (or ?, HELP)

    • Action: Requests a list of available commands.
    • Response: Returns a list of all public commands. If sent by an admin, it will also include the admin-only commands.

  2. ?APRSV

    • Action: Retrieves the firmware version and build information.
    • Response: A string containing the project name, board type, version number, and build date. Example: SQ2CPA LoRa APRS ESP32_V1 v1.0.0 2025-10-11

  3. ?APRSS

    • Action: Checks the APRS-IS connection status.
    • Response: Shows the APRS-IS server the device is currently connected to. Example: Connected to poland.aprs2.net

  4. ?APRSUP

    • Action: Gets the device’s current uptime.
    • Response: Returns the time in seconds since the last boot. Example: Uptime: 86400

  5. ?APRSGV

    • Action: Reads the internal and external voltage levels.
    • Response: Provides the battery and external power supply voltage readings. Example: Batt: 4.15V Ext: 5.02V

  6. ?APRSGM

    • Action: Fetches the packet transmission and reception statistics.
    • Response: Returns the count of transmitted (TX), received (RX), and digipeated packets. Example: Metrics - TX: 120 RX: 450 Digi: 55

  7. ?APRSGR

    • Action: Gets the RSSI (Received Signal Strength Indicator) of the last received LoRa packet.
    • Response: Returns the RSSI value in dBm. Example: Current RSSI: -89.50

Administrative Commands

These commands perform sensitive actions and can only be executed by callsigns listed in the device’s admin configuration.

  1. ?APRSR

    • Action: Immediately reboots the device.
    • Note: The device will not send a response; it will simply restart.

  2. ?APRSSB

    • Action: Forces the device to transmit a beacon packet as soon as possible.
    • Response: Beacon will be send in a while

  3. ?APRSST

    • Action: Re-sends the initial telemetry packets (the telemetry parameter, unit and equation definitions). Useful when an APRS server or client has lost the telemetry definitions and is no longer interpreting your telemetry values correctly.
    • Response: Telemetry initialization resend queued, or Telemetry is not active if telemetry is disabled.
    • ➡️ Learn more about telemetry: APRS Telemetry

  4. ?APRSU

    • Action: Initiates a remote Over-The-Air (OTA) firmware update to the latest available version.
    • Response: Remote update started to latest

  5. ?APRSU <version>

    • Action: Initiates a remote OTA firmware update to a specific version number.
    • Response: Remote update started to <version> (e.g., Remote update started to v1.2.3)

  6. ?APRSMR

    • Action: Resets the packet counters (TX, RX, Digi) back to zero.
    • Response: Metrics reset complete

  7. ?APRSGA

    • Action: Retrieves the device’s local IP address on the Wi-Fi network.
    • Response: The local IP address (e.g., 192.168.1.100) or Not connected if not on Wi-Fi.

  8. ?APRSAP

    • Action: Manually enables the Wi-Fi Access Point (AP) mode. This is useful for reconfiguring the device if it cannot connect to a saved Wi-Fi network.
    • Response: AP started or an error message if it cannot be enabled.

  9. ?APRSELP

    • Action: Forces the device to exit from low-power mode. This command is only available if the low-power mode is enabled in the configuration.
    • Response: Exited low power mode!

  10. ?APRSNET

    • Action: Reloads the network connection. If the device is configured as a Wi-Fi client, it will attempt to reconnect. If it cannot connect or is configured as an Access Point, it will start the AP mode.
    • Response: WiFi reloading started

  11. ?APRSTX ON / ?APRSTX OFF

    • Action: Enables or disables the LoRa transmitter.
    • Response: LoRa TX enabled or LoRa TX disabled. Sending ?APRSTX without a parameter returns the usage hint Use ?APRSTX ON/OFF.
    • Note: When TX is OFF, the device will not transmit any LoRa packets. Turning TX OFF reboots the device immediately; turning it ON schedules a restart a few seconds later to apply the change.
  12. ?APRSDIGI OFF / ?APRSDIGI OWN / ?APRSDIGI WIDE1 / ?APRSDIGI W1W2 / ?APRSDIGI WIDE2
    • Action: Sets the digipeater mode (this mirrors the Digi mode dropdown on the configuration page). The device restarts a few seconds after the change to apply it.
      • OFF - Disables digipeating functionality.
      • OWN - Repeats only packets addressed to the device’s own callsign (or alias).
      • WIDE1 - Acts as a WIDE1 (fill-in) digi.
      • W1W2 - Acts as a combined WIDE1+WIDE2 digi (the alias WIDE12 also works).
      • WIDE2 - Acts as a WIDE2 digi (first unused address only).
    • Response: Confirmation of the digi mode change (e.g. Digi mode set to W1+W2). Sending ?APRSDIGI without a parameter returns the usage hint Use ?APRSDIGI OFF/OWN/WIDE1/W1W2/WIDE2.
    • ➡️ For what each mode does, see Configuration → Digipeater Settings.

  13. ?APRSCD

    • Action: Returns a compact, machine-readable status dump of the device. This command is intended primarily for applications (such as the mobile app) rather than for manual reading.

    • Response: A single pipe-delimited (|) line with the following fields, in order:

      path|digiMode|wifiActive,wifiRSSI|beaconRF,beaconIS,beaconInterval|txPower|tncMode|aprsisServer|wx|syslogEnabled,syslogMode|ramUsed/ramTotal
      • path: Beacon path, or - if none.
      • digiMode: Current digi mode (0–4).
      • wifiActive,wifiRSSI: 1/0 for Wi-Fi connected, followed by the RSSI in dBm (0 when not connected).
      • beaconRF,beaconIS,beaconInterval: Beacon-via-RF flag, beacon-via-APRS-IS flag, and interval in minutes.
      • txPower: LoRa TX power in dBm.
      • tncMode: Bitmask — 1 = TNC server enabled, 2 = serial TNC enabled (USB or hardware), 3 = both.
      • aprsisServer: Configured APRS-IS server.
      • wx: 1/0 for WX telemetry enabled.
      • syslogEnabled,syslogMode: Syslog enabled flag and selected mode.
      • ramUsed/ramTotal: Heap usage in KB.

Radio Range Testing

The device supports automatic responses to PING messages for radio range testing purposes.