Modbus controller (#1779)

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

esphome/components/modbus_controller/switch/modbus_switch.cpp

@@ -0,0 +1,70 @@
+
+#include "modbus_switch.h"
+#include "esphome/core/log.h"
+namespace esphome {
+namespace modbus_controller {
+
+static const char *const TAG = "modbus_controller.switch";
+
+void ModbusSwitch::setup() {
+  // value isn't required
+  // without it we crash on save
+  this->get_initial_state();
+}
+void ModbusSwitch::dump_config() { LOG_SWITCH(TAG, "Modbus Controller Switch", this); }
+
+void ModbusSwitch::parse_and_publish(const std::vector<uint8_t> &data) {
+  bool value = false;
+  switch (this->register_type) {
+    case ModbusRegisterType::DISCRETE_INPUT:
+    case ModbusRegisterType::COIL:
+      // offset for coil is the actual number of the coil not the byte offset
+      value = coil_from_vector(this->offset, data);
+      break;
+    default:
+      value = get_data<uint16_t>(data, this->offset) & this->bitmask;
+      break;
+  }
+
+  // Is there a lambda registered
+  // call it with the pre converted value and the raw data array
+  if (this->publish_transform_func_) {
+    // the lambda can parse the response itself
+    auto val = (*this->publish_transform_func_)(this, value, data);
+    if (val.has_value()) {
+      ESP_LOGV(TAG, "Value overwritten by lambda");
+      value = val.value();
+    }
+  }
+
+  ESP_LOGV(TAG, "Publish '%s': new value = %s type = %d address = %X offset = %x", this->get_name().c_str(),
+           ONOFF(value), (int) this->register_type, this->start_address, this->offset);
+  this->publish_state(value);
+}
+
+void ModbusSwitch::write_state(bool state) {
+  // This will be called every time the user requests a state change.
+  ModbusCommandItem cmd;
+  ESP_LOGV(TAG, "write_state '%s': new value = %s type = %d address = %X offset = %x", this->get_name().c_str(),
+           ONOFF(state), (int) this->register_type, this->start_address, this->offset);
+  switch (this->register_type) {
+    case ModbusRegisterType::COIL:
+      // offset for coil and discrete inputs is the coil/register number not bytes
+      cmd = ModbusCommandItem::create_write_single_coil(parent_, this->start_address + this->offset, state);
+      break;
+    case ModbusRegisterType::DISCRETE_INPUT:
+      cmd = ModbusCommandItem::create_write_single_command(parent_, this->start_address + this->offset, state);
+      break;
+
+    default:
+      // since offset is in bytes and a register is 16 bits we get the start by adding offset/2
+      cmd = ModbusCommandItem::create_write_single_command(parent_, this->start_address + this->offset / 2,
+                                                           state ? 0xFFFF & this->bitmask : 0);
+      break;
+  }
+  this->parent_->queue_command(cmd);
+  publish_state(state);
+}
+// ModbusSwitch end
+}  // namespace modbus_controller
+}  // namespace esphome