Add SONOFF Dongle-LMG21 range extender fingerprint

drivers/SmartThings/zigbee-range-extender/fingerprints.yml

@@ -33,4 +33,9 @@ zigbeeManufacturer:
     deviceLabel: frient Zigbee Range Extender
     manufacturer: frient A/S
     model: REXZB-111
-    deviceProfileName: range-extender-battery-source
+    deviceProfileName: range-extender-battery-source
+  - id: "SONOFF/Router"
+    deviceLabel: "SONOFF Zigbee Range Extender"
+    manufacturer: "SONOFF"
+    model: "Dongle-LMG21"
+    deviceProfileName: range-extender-signal

drivers/SmartThings/zigbee-range-extender/profiles/range-extender-signal.yml

@@ -0,0 +1,10 @@
+name: range-extender-signal
+components:
+- id: main
+  capabilities:
+  - id: signalStrength
+    version: 1
+  - id: refresh
+    version: 1
+  categories:
+  - name: Networking

drivers/SmartThings/zigbee-range-extender/src/init.lua

@@ -15,7 +15,8 @@ end
 local zigbee_range_driver_template = {
   supported_capabilities = {
     capabilities.refresh,
-    capabilities.battery
+    capabilities.battery,
+    capabilities.signalStrength
   },
   capability_handlers = {
     [capabilities.refresh.ID] = {

drivers/SmartThings/zigbee-range-extender/src/range-extender-signal/can_handle.lua

@@ -0,0 +1,14 @@
+-- Copyright 2026 SmartThings, Inc.
+-- Licensed under the Apache License, Version 2.0
+
+local function can_handle(opts, driver, device)
+  local FINGERPRINTS = require("range-extender-signal.fingerprints")
+  for _, fingerprint in ipairs(FINGERPRINTS) do
+    if device:get_manufacturer() == fingerprint.mfr and device:get_model() == fingerprint.model then
+      return true, require("range-extender-signal")
+    end
+  end
+  return false
+end
+
+return can_handle

drivers/SmartThings/zigbee-range-extender/src/range-extender-signal/fingerprints.lua

@@ -0,0 +1,8 @@
+-- Copyright 2026 SmartThings, Inc.
+-- Licensed under the Apache License, Version 2.0
+
+local RANGE_EXTENDER_SIGNAL_FINGERPRINTS = {
+  { mfr = "SONOFF", model = "Dongle-LMG21" },
+}
+
+return RANGE_EXTENDER_SIGNAL_FINGERPRINTS

drivers/SmartThings/zigbee-range-extender/src/range-extender-signal/init.lua

@@ -0,0 +1,45 @@
+-- Copyright 2026 SmartThings, Inc.
+-- Licensed under the Apache License, Version 2.0
+
+local capabilities = require "st.capabilities"
+local Basic = (require "st.zigbee.zcl.clusters").Basic
+
+local function refresh_signal_strength(driver, device)
+  -- The reply carries the hub's received-message RSSI and LQI.
+  device:send(Basic.attributes.ZCLVersion:read(device))
+end
+
+local function info_changed(driver, device, event, args)
+  if device.profile.id ~= args.old_st_store.profile.id then
+    refresh_signal_strength(driver, device)
+  end
+end
+
+local function signal_strength_handler(driver, device, value, zb_rx)
+  -- A device can change profiles while this sub-driver is loaded.
+  if not device:supports_capability(capabilities.signalStrength, "main") then
+    return
+  end
+
+  if zb_rx.lqi ~= nil and zb_rx.lqi.value ~= nil then
+    device:emit_event(capabilities.signalStrength.lqi(zb_rx.lqi.value))
+  end
+  if zb_rx.rssi ~= nil and zb_rx.rssi.value ~= nil then
+    device:emit_event(capabilities.signalStrength.rssi({ value = zb_rx.rssi.value, unit = "dBm" }))
+  end
+end
+
+return {
+  NAME = "Range Extender Signal Strength",
+  lifecycle_handlers = {
+    infoChanged = info_changed,
+  },
+  zigbee_handlers = {
+    attr = {
+      [Basic.ID] = {
+        [Basic.attributes.ZCLVersion.ID] = signal_strength_handler,
+      },
+    },
+  },
+  can_handle = require("range-extender-signal.can_handle"),
+}

drivers/SmartThings/zigbee-range-extender/src/sub_drivers.lua

@@ -4,5 +4,6 @@
 local lazy_load_if_possible = require "lazy_load_subdriver"
 local sub_drivers = {
    lazy_load_if_possible("frient"),
+   lazy_load_if_possible("range-extender-signal"),
 }
 return sub_drivers

drivers/SmartThings/zigbee-range-extender/src/test/test_range_extender_signal.lua

@@ -0,0 +1,222 @@
+-- Copyright 2026 SmartThings, Inc.
+-- Licensed under the Apache License, Version 2.0
+
+local test = require "integration_test"
+local capabilities = require "st.capabilities"
+local clusters = require "st.zigbee.zcl.clusters"
+local data_types = require "st.zigbee.data_types"
+local t_utils = require "integration_test.utils"
+local zigbee_test_utils = require "integration_test.zigbee_test_utils"
+
+local Basic = clusters.Basic
+
+local function build_device(profile, manufacturer, model)
+  return test.mock_device.build_test_zigbee_device({
+    profile = t_utils.get_profile_definition(profile),
+    zigbee_endpoints = {
+      [0x01] = {
+        id = 0x01,
+        manufacturer = manufacturer or "SONOFF",
+        model = model or "Dongle-LMG21",
+        server_clusters = { Basic.ID },
+      },
+    },
+  })
+end
+
+local mock_device = build_device("range-extender-signal.yml")
+local base_device = build_device("range-extender.yml")
+local other_manufacturer = build_device("range-extender-signal.yml", "Other manufacturer")
+local other_model = build_device("range-extender-signal.yml", "SONOFF", "Other model")
+
+local function read_response(device, lqi, rssi)
+  local message = Basic.attributes.ZCLVersion:build_test_read_attr_response(device, 3)
+  message.lqi = data_types.Uint8(lqi)
+  message.rssi = data_types.Int8(rssi)
+  return message
+end
+
+local function expect_signal_strength(device, lqi, rssi)
+  test.socket.capability:__expect_send(device:generate_test_message(
+    "main", capabilities.signalStrength.lqi(lqi)))
+  test.socket.capability:__expect_send(device:generate_test_message(
+    "main", capabilities.signalStrength.rssi({ value = rssi, unit = "dBm" })))
+end
+
+local function base_test_init()
+  test.mock_device.add_test_device(base_device)
+end
+
+zigbee_test_utils.prepare_zigbee_env_info()
+test.set_test_init_function(function()
+  test.mock_device.add_test_device(mock_device)
+end)
+
+test.register_coroutine_test(
+  "Refresh reads the device and publishes received signal strength",
+  function()
+    test.socket.capability:__queue_receive({
+      mock_device.id,
+      { capability = "refresh", component = "main", command = "refresh", args = {} },
+    })
+    test.socket.zigbee:__expect_send({ mock_device.id, Basic.attributes.ZCLVersion:read(mock_device) })
+    test.wait_for_events()
+
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 203, -67) })
+    expect_signal_strength(mock_device, 203, -67)
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+test.register_coroutine_test(
+  "Configuration obtains an initial signal sample without configuring reporting",
+  function()
+    test.socket.device_lifecycle:__queue_receive({ mock_device.id, "doConfigure" })
+    test.socket.zigbee:__expect_send({ mock_device.id, Basic.attributes.ZCLVersion:read(mock_device) })
+    mock_device:expect_metadata_update({ provisioning_state = "PROVISIONED" })
+    test.wait_for_events()
+
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 169, -74) })
+    expect_signal_strength(mock_device, 169, -74)
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+test.register_coroutine_test(
+  "Health polling obtains new signal samples every five minutes",
+  function()
+    test.wait_for_events()
+    test.mock_time.advance_time(300)
+    test.socket.zigbee:__expect_send({ mock_device.id, Basic.attributes.ZCLVersion:read(mock_device) })
+    test.wait_for_events()
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 211, -61) })
+    expect_signal_strength(mock_device, 211, -61)
+    test.wait_for_events()
+
+    test.mock_time.advance_time(300)
+    test.socket.zigbee:__expect_send({ mock_device.id, Basic.attributes.ZCLVersion:read(mock_device) })
+    test.wait_for_events()
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 83, -91) })
+    expect_signal_strength(mock_device, 83, -91)
+  end,
+  {
+    min_api_version = 17,
+    test_init = function()
+      test.mock_device.add_test_device(mock_device)
+      test.timer.__create_and_queue_test_time_advance_timer(300, "interval", 2)
+    end,
+  }
+)
+
+test.register_coroutine_test(
+  "Zero LQI and zero dBm are preserved in received samples",
+  function()
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 0, 0) })
+    expect_signal_strength(mock_device, 0, 0)
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+test.register_coroutine_test(
+  "Signal strength preserves Zigbee metadata boundary values",
+  function()
+    test.socket.zigbee:__queue_receive({ mock_device.id, read_response(mock_device, 255, -128) })
+    expect_signal_strength(mock_device, 255, -128)
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+test.register_coroutine_test(
+  "Unsolicited Basic reports also update signal strength",
+  function()
+    local report = Basic.attributes.ZCLVersion:build_test_attr_report(mock_device, 3)
+    report.lqi = data_types.Uint8(127)
+    report.rssi = data_types.Int8(-82)
+    test.socket.zigbee:__queue_receive({ mock_device.id, report })
+    expect_signal_strength(mock_device, 127, -82)
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+test.register_coroutine_test(
+  "Initializing a base profile does not automatically add signal strength capabilities",
+  function()
+    test.wait_for_events()
+  end,
+  {
+    min_api_version = 17,
+    test_init = base_test_init,
+  }
+)
+
+test.register_coroutine_test(
+  "Samples are not published for a base profile without signal strength",
+  function()
+    test.socket.zigbee:__queue_receive({ base_device.id, read_response(base_device, 196, -70) })
+  end,
+  {
+    min_api_version = 17,
+    test_init = base_test_init,
+  }
+)
+
+test.register_coroutine_test(
+  "Changing to the signal strength profile obtains and publishes an initial sample",
+  function()
+    test.socket.device_lifecycle:__queue_receive(base_device:generate_info_changed({
+      profile = t_utils.get_profile_definition("range-extender-signal.yml"),
+    }))
+    test.socket.zigbee:__expect_send({ base_device.id, Basic.attributes.ZCLVersion:read(base_device) })
+    test.wait_for_events()
+
+    test.socket.zigbee:__queue_receive({ base_device.id, read_response(base_device, 184, -72) })
+    expect_signal_strength(base_device, 184, -72)
+  end,
+  {
+    min_api_version = 17,
+    test_init = base_test_init,
+  }
+)
+
+test.register_coroutine_test(
+  "Initializing or changing preferences does not request another signal sample",
+  function()
+    test.socket.device_lifecycle:__queue_receive({ mock_device.id, "init" })
+    test.wait_for_events()
+    test.socket.device_lifecycle:__queue_receive(mock_device:generate_info_changed({ preferences = {} }))
+  end,
+  {
+    min_api_version = 17,
+  }
+)
+
+for _, case in ipairs({
+  { name = "a different manufacturer with the supported model", device = other_manufacturer },
+  { name = "a different model with the supported manufacturer", device = other_model },
+}) do
+  local device = case.device
+  test.register_coroutine_test(
+    "Signal strength subdriver rejects " .. case.name,
+    function()
+      test.socket.zigbee:__queue_receive({ device.id, read_response(device, 196, -70) })
+    end,
+    {
+      min_api_version = 17,
+      test_init = function()
+        test.mock_device.add_test_device(device)
+      end,
+    }
+  )
+end
+
+test.run_registered_tests()