[dallas_temp] add support for index (#11346)

esphome/components/dallas_temp/dallas_temp.cpp

@@ -70,7 +70,7 @@ bool DallasTemperatureSensor::read_scratch_pad_() {
 }
 
 void DallasTemperatureSensor::setup() {
-  if (!this->check_address_())
+  if (!this->check_address_or_index_())
     return;
   if (!this->read_scratch_pad_())
     return;

esphome/components/one_wire/__init__.py

@@ -1,6 +1,6 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.const import CONF_ADDRESS
+from esphome.const import CONF_ADDRESS, CONF_INDEX
 
 CODEOWNERS = ["@ssieb"]
 
@@ -21,7 +21,8 @@ def one_wire_device_schema():
     return cv.Schema(
         {
             cv.GenerateID(CONF_ONE_WIRE_ID): cv.use_id(OneWireBus),
-            cv.Optional(CONF_ADDRESS): cv.hex_uint64_t,
+            cv.Exclusive(CONF_ADDRESS, "index_or_address"): cv.hex_uint64_t,
+            cv.Exclusive(CONF_INDEX, "index_or_address"): cv.uint8_t,
         }
     )
 
@@ -37,3 +38,5 @@ async def register_one_wire_device(var, config):
     cg.add(var.set_one_wire_bus(parent))
     if (address := config.get(CONF_ADDRESS)) is not None:
         cg.add(var.set_address(address))
+    if (index := config.get(CONF_INDEX)) is not None:
+        cg.add(var.set_index(index))

esphome/components/one_wire/one_wire.cpp

@@ -18,10 +18,20 @@ bool OneWireDevice::send_command_(uint8_t cmd) {
   return true;
 }
 
-bool OneWireDevice::check_address_() {
+bool OneWireDevice::check_address_or_index_() {
   if (this->address_ != 0)
     return true;
   auto devices = this->bus_->get_devices();
+
+  if (this->index_ != INDEX_NOT_SET) {
+    if (this->index_ >= devices.size()) {
+      ESP_LOGE(TAG, "Index %d out of range, only %d devices found", this->index_, devices.size());
+      return false;
+    }
+    this->address_ = devices[this->index_];
+    return true;
+  }
+
   if (devices.empty()) {
     ESP_LOGE(TAG, "No devices, can't auto-select address");
     return false;

esphome/components/one_wire/one_wire.h

@@ -17,6 +17,8 @@ class OneWireDevice {
   /// @param address of the device
   void set_address(uint64_t address) { this->address_ = address; }
 
+  void set_index(uint8_t index) { this->index_ = index; }
+
   /// @brief store the pointer to the OneWireBus to use
   /// @param bus pointer to the OneWireBus object
   void set_one_wire_bus(OneWireBus *bus) { this->bus_ = bus; }
@@ -25,13 +27,16 @@ class OneWireDevice {
   const std::string &get_address_name();
 
  protected:
+  static constexpr uint8_t INDEX_NOT_SET = 255;
+
   uint64_t address_{0};
+  uint8_t index_{INDEX_NOT_SET};
   OneWireBus *bus_{nullptr};  ///< pointer to OneWireBus instance
   std::string address_name_;
 
   /// @brief find an address if necessary
   /// should be called from setup
-  bool check_address_();
+  bool check_address_or_index_();
 
   /// @brief send command on the bus
   /// @param cmd command to send

tests/components/dallas_temp/common.yaml

@@ -9,3 +9,6 @@ sensor:
     resolution: 9
   - platform: dallas_temp
     name: Dallas Temperature 2
+  - platform: dallas_temp
+    name: Dallas Temperature 3
+    index: 2