[sx126x] Add data whitening options (#17102)

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

esphome/components/sx126x/__init__.py

@@ -41,6 +41,8 @@ CONF_SPREADING_FACTOR = "spreading_factor"
 CONF_SYNC_VALUE = "sync_value"
 CONF_TCXO_VOLTAGE = "tcxo_voltage"
 CONF_TCXO_DELAY = "tcxo_delay"
+CONF_WHITENING_ENABLE = "whitening_enable"
+CONF_WHITENING_INITIAL = "whitening_initial"
 
 sx126x_ns = cg.esphome_ns.namespace("sx126x")
 SX126x = sx126x_ns.class_("SX126x", cg.Component, spi.SPIDevice)
@@ -232,6 +234,10 @@ CONFIG_SCHEMA = (
                 cv.positive_time_period_microseconds,
                 cv.Range(max=TimePeriod(microseconds=262144000)),
             ),
+            cv.Optional(CONF_WHITENING_ENABLE, default=False): cv.boolean,
+            cv.Optional(CONF_WHITENING_INITIAL, default=0x0100): cv.All(
+                cv.hex_int, cv.Range(min=0, max=0x1FF)
+            ),
         },
     )
     .extend(cv.COMPONENT_SCHEMA)
@@ -285,6 +291,8 @@ async def to_code(config: ConfigType) -> None:
     cg.add(var.set_rf_switch(config[CONF_RF_SWITCH]))
     cg.add(var.set_tcxo_voltage(config[CONF_TCXO_VOLTAGE]))
     cg.add(var.set_tcxo_delay(config[CONF_TCXO_DELAY]))
+    cg.add(var.set_whitening_enable(config[CONF_WHITENING_ENABLE]))
+    cg.add(var.set_whitening_initial(config[CONF_WHITENING_INITIAL]))
 
 
 NO_ARGS_ACTION_SCHEMA = automation.maybe_simple_id(

esphome/components/sx126x/sx126x.cpp

@@ -251,6 +251,16 @@ void SX126x::configure() {
       this->write_register_(REG_CRC_POLYNOMIAL, buf, 2);
     }
 
+    // set whitening params
+    if (this->whitening_enable_) {
+      // according to the datasheet, section 12 table 12-1 "The user should not
+      // change the value of the 7 MSB of this register"
+      this->read_register_(REG_WHITENING_INITIAL, buf, 1);
+      buf[0] = (buf[0] & 0xFE) | ((this->whitening_initial_ >> 8) & 0x01);
+      buf[1] = this->whitening_initial_ & 0xFF;
+      this->write_register_(REG_WHITENING_INITIAL, buf, 2);
+    }
+
     // set packet params and sync word
     this->set_packet_params_(this->get_max_packet_size());
     if (!this->sync_value_.empty()) {
@@ -297,7 +307,7 @@ void SX126x::set_packet_params_(uint8_t payload_length) {
     } else {
       buf[7] = 0x01;
     }
-    buf[8] = 0x00;
+    buf[8] = (this->whitening_enable_) ? 0x01 : 0x00;
     this->write_opcode_(RADIO_SET_PACKETPARAMS, buf, 9);
   }
 }
@@ -541,6 +551,10 @@ void SX126x::dump_config() {
     ESP_LOGCONFIG(TAG, "  Sync Value: 0x%s",
                   format_hex_to(hex_buf, this->sync_value_.data(), this->sync_value_.size()));
   }
+  ESP_LOGCONFIG(TAG, "  Whitening Enable: %s", TRUEFALSE(this->whitening_enable_));
+  if (this->whitening_enable_) {
+    ESP_LOGCONFIG(TAG, "  Whitening Initial: 0x%03x", this->whitening_initial_);
+  }
   if (this->is_failed()) {
     ESP_LOGE(TAG, "Configuring SX126x failed");
   }

esphome/components/sx126x/sx126x.h

@@ -71,6 +71,8 @@ class SX126x : public Component,
   void set_crc_size(uint8_t crc_size) { this->crc_size_ = crc_size; }
   void set_crc_polynomial(uint16_t crc_polynomial) { this->crc_polynomial_ = crc_polynomial; }
   void set_crc_initial(uint16_t crc_initial) { this->crc_initial_ = crc_initial; }
+  void set_whitening_enable(bool whitening_enable) { this->whitening_enable_ = whitening_enable; }
+  void set_whitening_initial(uint16_t whitening_initial) { this->whitening_initial_ = whitening_initial; }
   void set_deviation(uint32_t deviation) { this->deviation_ = deviation; }
   void set_dio1_pin(GPIOPin *dio1_pin) { this->dio1_pin_ = dio1_pin; }
   void set_frequency(uint32_t frequency) { this->frequency_ = frequency; }
@@ -128,6 +130,8 @@ class SX126x : public Component,
   uint8_t crc_size_{0};
   uint16_t crc_polynomial_{0};
   uint16_t crc_initial_{0};
+  bool whitening_enable_{false};
+  uint16_t whitening_initial_{0};
   uint32_t deviation_{0};
   uint32_t frequency_{0};
   uint32_t payload_length_{0};

esphome/components/sx126x/sx126x_reg.h

@@ -52,6 +52,7 @@ enum SX126xOpCode : uint8_t {
 
 enum SX126xRegister : uint16_t {
   REG_VERSION_STRING = 0x0320,
+  REG_WHITENING_INITIAL = 0x06B8,
   REG_CRC_INITIAL = 0x06BC,
   REG_CRC_POLYNOMIAL = 0x06BE,
   REG_GFSK_SYNCWORD = 0x06C0,

tests/components/sx126x/common.yaml

@@ -21,6 +21,8 @@ sx126x:
   coding_rate: CR_4_6
   tcxo_voltage: 1_8V
   tcxo_delay: 5ms
+  whitening_enable: false
+  whitening_initial: 0x1FF
   on_packet:
     then:
       - lambda: |-