[daikin_brc] Add sub_unit parameter for multi-unit addressing (#15234)

Co-authored-by: J. Nick Koston <nick@home-assistant.io>
Co-authored-by: J. Nick Koston <nick@koston.org>

esphome/components/daikin_brc/climate.py

@@ -6,6 +6,8 @@ from esphome.types import ConfigType
 
 AUTO_LOAD = ["climate_ir"]
 
+CONF_SUB_UNIT = "sub_unit"
+
 daikin_brc_ns = cg.esphome_ns.namespace("daikin_brc")
 DaikinBrcClimate = daikin_brc_ns.class_("DaikinBrcClimate", climate_ir.ClimateIR)
 
@@ -13,6 +15,7 @@ DaikinBrcClimate = daikin_brc_ns.class_("DaikinBrcClimate", climate_ir.ClimateIR
 CONFIG_SCHEMA = climate_ir.climate_ir_with_receiver_schema(DaikinBrcClimate).extend(
     {
         cv.Optional(CONF_USE_FAHRENHEIT, default=False): cv.boolean,
+        cv.Optional(CONF_SUB_UNIT, default=0): cv.int_range(min=0, max=5),
     }
 )
 
@@ -20,3 +23,4 @@ CONFIG_SCHEMA = climate_ir.climate_ir_with_receiver_schema(DaikinBrcClimate).ext
 async def to_code(config: ConfigType) -> None:
     var = await climate_ir.new_climate_ir(config)
     cg.add(var.set_fahrenheit(config[CONF_USE_FAHRENHEIT]))
+    cg.add(var.set_sub_unit(config[CONF_SUB_UNIT]))

esphome/components/daikin_brc/daikin_brc.cpp

@@ -20,13 +20,18 @@ void DaikinBrcClimate::transmit_state() {
                                                           0xDA, 0x17, 0x18, 0x00, 0x00, 0x00, 0x00, 0x00,
                                                           0x00, 0x00, 0x00, 0x00, 0x20, 0x00};
 
+  // The low 3 bits of the frame header byte address the indoor unit, in the preamble and the state frame
+  remote_state[3] |= this->sub_unit_;
+  remote_state[10] |= this->sub_unit_;
+  remote_state[6] += this->sub_unit_;  // preamble checksum covers byte 3
+
   remote_state[12] = this->alt_mode_();
   remote_state[13] = this->mode_button_;
   remote_state[14] = this->operation_mode_();
   remote_state[17] = this->temperature_();
   remote_state[18] = this->fan_speed_swing_();
 
-  // Calculate checksum
+  // Calculate state frame checksum
   for (int i = DAIKIN_BRC_PREAMBLE_SIZE; i < DAIKIN_BRC_TRANSMIT_FRAME_SIZE - 1; i++) {
     remote_state[DAIKIN_BRC_TRANSMIT_FRAME_SIZE - 1] += remote_state[i];
   }
@@ -254,8 +259,8 @@ bool DaikinBrcClimate::on_receive(remote_base::RemoteReceiveData data) {
       if (byte != 0x17)
         return false;
     } else if (pos == 3) {
-      // frame header
-      if (byte != 0x18)
+      // frame header, with this unit's address in the low 3 bits
+      if (byte != (0x18 | this->sub_unit_))
         return false;
     } else if (pos == 4) {
       // frame type

esphome/components/daikin_brc/daikin_brc.h

@@ -60,6 +60,8 @@ class DaikinBrcClimate final : public climate_ir::ClimateIR {
     this->fahrenheit_ = value;
     this->temperature_step_ = value ? 0.5f : 1.0f;
   }
+  /// Which indoor unit (0 to 5) this climate addresses on a multi-unit system
+  void set_sub_unit(uint8_t value) { this->sub_unit_ = value; }
 
  protected:
   uint8_t mode_button_ = 0x00;
@@ -75,6 +77,7 @@ class DaikinBrcClimate final : public climate_ir::ClimateIR {
   bool on_receive(remote_base::RemoteReceiveData data) override;
   bool parse_state_frame_(const uint8_t frame[]);
   bool fahrenheit_{false};
+  uint8_t sub_unit_{0};
 };
 
 }  // namespace esphome::daikin_brc

tests/components/daikin_brc/common.yaml

@@ -2,3 +2,7 @@ climate:
   - platform: daikin_brc
     name: Daikin_brc Climate
     transmitter_id: xmitr
+  - platform: daikin_brc
+    name: Daikin_brc Climate Unit 2
+    transmitter_id: xmitr
+    sub_unit: 1

tests/components/daikin_brc/test.esp32-idf.yaml

@@ -1,4 +1,3 @@
 packages:
   remote_transmitter: !include ../../test_build_components/common/remote_transmitter/esp32-idf.yaml
-
-<<: !include common.yaml
+  daikin_brc: !include common.yaml

tests/components/daikin_brc/test.esp8266-ard.yaml

@@ -1,4 +1,3 @@
 packages:
   remote_transmitter: !include ../../test_build_components/common/remote_transmitter/esp8266-ard.yaml
-
-<<: !include common.yaml
+  daikin_brc: !include common.yaml