CAN bus: support remote transmission request flag for canbus.send (#3193)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/canbus/__init__.py

@@ -10,6 +10,7 @@ IS_PLATFORM_COMPONENT = True
 CONF_CAN_ID = "can_id"
 CONF_CAN_ID_MASK = "can_id_mask"
 CONF_USE_EXTENDED_ID = "use_extended_id"
+CONF_REMOTE_TRANSMISSION_REQUEST = "remote_transmission_request"
 CONF_CANBUS_ID = "canbus_id"
 CONF_BIT_RATE = "bit_rate"
 CONF_ON_FRAME = "on_frame"
@@ -122,6 +123,7 @@ async def register_canbus(var, config):
             cv.GenerateID(CONF_CANBUS_ID): cv.use_id(CanbusComponent),
             cv.Optional(CONF_CAN_ID): cv.int_range(min=0, max=0x1FFFFFFF),
             cv.Optional(CONF_USE_EXTENDED_ID, default=False): cv.boolean,
+            cv.Optional(CONF_REMOTE_TRANSMISSION_REQUEST, default=False): cv.boolean,
             cv.Required(CONF_DATA): cv.templatable(validate_raw_data),
         },
         validate_id,
@@ -140,6 +142,11 @@ async def canbus_action_to_code(config, action_id, template_arg, args):
     )
     cg.add(var.set_use_extended_id(use_extended_id))
 
+    remote_transmission_request = await cg.templatable(
+        config[CONF_REMOTE_TRANSMISSION_REQUEST], args, bool
+    )
+    cg.add(var.set_remote_transmission_request(remote_transmission_request))
+
     data = config[CONF_DATA]
     if isinstance(data, bytes):
         data = [int(x) for x in data]

esphome/components/canbus/canbus.cpp

@@ -22,20 +22,22 @@ void Canbus::dump_config() {
   }
 }
 
-void Canbus::send_data(uint32_t can_id, bool use_extended_id, const std::vector<uint8_t> &data) {
+void Canbus::send_data(uint32_t can_id, bool use_extended_id, bool remote_transmission_request,
+                       const std::vector<uint8_t> &data) {
   struct CanFrame can_message;
 
   uint8_t size = static_cast<uint8_t>(data.size());
   if (use_extended_id) {
-    ESP_LOGD(TAG, "send extended id=0x%08x size=%d", can_id, size);
+    ESP_LOGD(TAG, "send extended id=0x%08x rtr=%s size=%d", can_id, TRUEFALSE(remote_transmission_request), size);
   } else {
-    ESP_LOGD(TAG, "send extended id=0x%03x size=%d", can_id, size);
+    ESP_LOGD(TAG, "send extended id=0x%03x rtr=%s size=%d", can_id, TRUEFALSE(remote_transmission_request), size);
   }
   if (size > CAN_MAX_DATA_LENGTH)
     size = CAN_MAX_DATA_LENGTH;
   can_message.can_data_length_code = size;
   can_message.can_id = can_id;
   can_message.use_extended_id = use_extended_id;
+  can_message.remote_transmission_request = remote_transmission_request;
 
   for (int i = 0; i < size; i++) {
     can_message.data[i] = data[i];

esphome/components/canbus/canbus.h

@@ -62,7 +62,12 @@ class Canbus : public Component {
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
   void loop() override;
 
-  void send_data(uint32_t can_id, bool use_extended_id, const std::vector<uint8_t> &data);
+  void send_data(uint32_t can_id, bool use_extended_id, bool remote_transmission_request,
+                 const std::vector<uint8_t> &data);
+  void send_data(uint32_t can_id, bool use_extended_id, const std::vector<uint8_t> &data) {
+    // for backwards compatibility only
+    this->send_data(can_id, use_extended_id, false, data);
+  }
   void set_can_id(uint32_t can_id) { this->can_id_ = can_id; }
   void set_use_extended_id(bool use_extended_id) { this->use_extended_id_ = use_extended_id; }
   void set_bitrate(CanSpeed bit_rate) { this->bit_rate_ = bit_rate; }
@@ -96,21 +101,26 @@ template<typename... Ts> class CanbusSendAction : public Action<Ts...>, public P
 
   void set_use_extended_id(bool use_extended_id) { this->use_extended_id_ = use_extended_id; }
 
+  void set_remote_transmission_request(bool remote_transmission_request) {
+    this->remote_transmission_request_ = remote_transmission_request;
+  }
+
   void play(Ts... x) override {
     auto can_id = this->can_id_.has_value() ? *this->can_id_ : this->parent_->can_id_;
     auto use_extended_id =
         this->use_extended_id_.has_value() ? *this->use_extended_id_ : this->parent_->use_extended_id_;
     if (this->static_) {
-      this->parent_->send_data(can_id, use_extended_id, this->data_static_);
+      this->parent_->send_data(can_id, use_extended_id, this->remote_transmission_request_, this->data_static_);
     } else {
       auto val = this->data_func_(x...);
-      this->parent_->send_data(can_id, use_extended_id, val);
+      this->parent_->send_data(can_id, use_extended_id, this->remote_transmission_request_, val);
     }
   }
 
  protected:
   optional<uint32_t> can_id_{};
   optional<bool> use_extended_id_{};
+  bool remote_transmission_request_{false};
   bool static_{false};
   std::function<std::vector<uint8_t>(Ts...)> data_func_{};
   std::vector<uint8_t> data_static_{};

tests/test1.yaml

@@ -2616,6 +2616,16 @@ text_sensor:
           canbus_id: esp32_internal_can
           can_id: 23
           data: [0x10, 0x20, 0x30]
+      - canbus.send:
+          canbus_id: mcp2515_can
+          can_id: 24
+          remote_transmission_request: true
+          data: []
+      - canbus.send:
+          canbus_id: esp32_internal_can
+          can_id: 24
+          remote_transmission_request: true
+          data: []
   - platform: template
     name: Template Text Sensor
     id: ${textname}_text