[openthread] Add tx power option (#14200)

Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

esphome/components/openthread/__init__.py

@@ -4,13 +4,20 @@ from esphome.components.esp32 import (
     VARIANT_ESP32C6,
     VARIANT_ESP32H2,
     add_idf_sdkconfig_option,
+    get_esp32_variant,
     include_builtin_idf_component,
     only_on_variant,
     require_vfs_select,
 )
 from esphome.components.mdns import MDNSComponent, enable_mdns_storage
 import esphome.config_validation as cv
-from esphome.const import CONF_CHANNEL, CONF_ENABLE_IPV6, CONF_ID, CONF_USE_ADDRESS
+from esphome.const import (
+    CONF_CHANNEL,
+    CONF_ENABLE_IPV6,
+    CONF_ID,
+    CONF_OUTPUT_POWER,
+    CONF_USE_ADDRESS,
+)
 from esphome.core import CORE, TimePeriodMilliseconds
 import esphome.final_validate as fv
 from esphome.types import ConfigType
@@ -45,6 +52,20 @@ CONF_DEVICE_TYPES = [
 ]
 
 
+def _validate_txpower(value):
+    if CORE.is_esp32:
+        variant = get_esp32_variant()
+
+        # HW limits: Datasheet section "802.15.4 RF Transmitter (TX) Characteristics"
+        # Further regulatory/soft limit may apply, e.g. by region
+        if variant in (VARIANT_ESP32C6, VARIANT_ESP32C5):
+            return cv.int_range(min=-15, max=20)(value)
+        if variant == VARIANT_ESP32H2:
+            return cv.int_range(min=-24, max=20)(value)
+
+    return value  # Unsupported, fail later with clear error
+
+
 def set_sdkconfig_options(config):
     # and expose options for using SPI/UART RCPs
     add_idf_sdkconfig_option("CONFIG_IEEE802154_ENABLED", True)
@@ -155,6 +176,10 @@ CONFIG_SCHEMA = cv.All(
             cv.Optional(CONF_TLV): cv.string_strict,
             cv.Optional(CONF_USE_ADDRESS): cv.string_strict,
             cv.Optional(CONF_POLL_PERIOD): cv.positive_time_period_milliseconds,
+            cv.Optional(CONF_OUTPUT_POWER): cv.All(
+                cv.decibel,
+                _validate_txpower,
+            ),
         }
     ).extend(_CONNECTION_SCHEMA),
     cv.has_exactly_one_key(CONF_NETWORK_KEY, CONF_TLV),
@@ -197,4 +222,7 @@ async def to_code(config):
     cg.add(srp.set_mdns(mdns_component))
     await cg.register_component(srp, config)
 
+    if (output_power := config.get(CONF_OUTPUT_POWER)) is not None:
+        cg.add(ot.set_output_power(output_power))
+
     set_sdkconfig_options(config)

esphome/components/openthread/openthread.cpp

@@ -43,6 +43,9 @@ void OpenThreadComponent::dump_config() {
     ESP_LOGCONFIG(TAG, "  Device is configured as Minimal End Device (MED)");
   }
 #endif
+  if (this->output_power_.has_value()) {
+    ESP_LOGCONFIG(TAG, "  Output power: %" PRId8 "dBm", *this->output_power_);
+  }
 }
 
 bool OpenThreadComponent::is_connected() {

esphome/components/openthread/openthread.h

@@ -38,6 +38,7 @@ class OpenThreadComponent : public Component {
 #if CONFIG_OPENTHREAD_MTD
   void set_poll_period(uint32_t poll_period) { this->poll_period_ = poll_period; }
 #endif
+  void set_output_power(int8_t output_power) { this->output_power_ = output_power; }
 
  protected:
   std::optional<otIp6Address> get_omr_address_(InstanceLock &lock);
@@ -45,6 +46,7 @@ class OpenThreadComponent : public Component {
 #if CONFIG_OPENTHREAD_MTD
   uint32_t poll_period_{0};
 #endif
+  std::optional<int8_t> output_power_{};
   bool teardown_started_{false};
   bool teardown_complete_{false};
 

esphome/components/openthread/openthread_esp.cpp

@@ -135,6 +135,12 @@ void OpenThreadComponent::ot_main() {
            TRUEFALSE(link_mode_config.mRxOnWhenIdle));
 #endif
 
+  if (this->output_power_.has_value()) {
+    if (const auto err = otPlatRadioSetTransmitPower(instance, *this->output_power_); err != OT_ERROR_NONE) {
+      ESP_LOGE(TAG, "Failed to set power: %s", otThreadErrorToString(err));
+    }
+  }
+
   // Run the main loop
 #if CONFIG_OPENTHREAD_CLI
   esp_openthread_cli_create_task();

tests/components/openthread/test.esp32-c6-idf.yaml

@@ -13,3 +13,4 @@ openthread:
   force_dataset: true
   use_address: open-thread-test.local
   poll_period: 20sec
+  output_power: 1dBm