Add support for ESP32 DAC (#1071)

* Add support for ESP32 onboard DAC

* Newlines

* Tests

esphome/components/esp32_dac/esp32_dac.cpp

@@ -0,0 +1,37 @@
+#include "esp32_dac.h"
+#include "esphome/core/log.h"
+#include "esphome/core/helpers.h"
+
+#ifdef ARDUINO_ARCH_ESP32
+
+#include <esp32-hal-dac.h>
+
+namespace esphome {
+namespace esp32_dac {
+
+static const char *TAG = "esp32_dac";
+
+void ESP32DAC::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up ESP32 DAC Output...");
+  this->pin_->setup();
+  this->turn_off();
+}
+
+void ESP32DAC::dump_config() {
+  ESP_LOGCONFIG(TAG, "ESP32 DAC:");
+  LOG_PIN("  Pin: ", this->pin_);
+  LOG_FLOAT_OUTPUT(this);
+}
+
+void ESP32DAC::write_state(float state) {
+  if (this->pin_->is_inverted())
+    state = 1.0f - state;
+
+  state = state * 255;
+  dacWrite(this->pin_->get_pin(), state);
+}
+
+}  // namespace esp32_dac
+}  // namespace esphome
+
+#endif

esphome/components/esp32_dac/esp32_dac.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/esphal.h"
+#include "esphome/core/automation.h"
+#include "esphome/components/output/float_output.h"
+
+#ifdef ARDUINO_ARCH_ESP32
+
+namespace esphome {
+namespace esp32_dac {
+
+class ESP32DAC : public output::FloatOutput, public Component {
+ public:
+  void set_pin(GPIOPin *pin) { pin_ = pin; }
+
+  /// Initialize pin
+  void setup() override;
+  void dump_config() override;
+  /// HARDWARE setup_priority
+  float get_setup_priority() const override { return setup_priority::HARDWARE; }
+
+ protected:
+  void write_state(float state) override;
+
+  GPIOPin *pin_;
+};
+
+}  // namespace esp32_dac
+}  // namespace esphome
+
+#endif

esphome/components/esp32_dac/output.py

@@ -0,0 +1,31 @@
+from esphome import pins
+from esphome.components import output
+import esphome.config_validation as cv
+import esphome.codegen as cg
+from esphome.const import CONF_ID, CONF_NUMBER, CONF_PIN, ESP_PLATFORM_ESP32
+
+ESP_PLATFORMS = [ESP_PLATFORM_ESP32]
+
+
+def valid_dac_pin(value):
+    num = value[CONF_NUMBER]
+    cv.one_of(25, 26)(num)
+    return value
+
+
+esp32_dac_ns = cg.esphome_ns.namespace('esp32_dac')
+ESP32DAC = esp32_dac_ns.class_('ESP32DAC', output.FloatOutput, cg.Component)
+
+CONFIG_SCHEMA = output.FLOAT_OUTPUT_SCHEMA.extend({
+    cv.Required(CONF_ID): cv.declare_id(ESP32DAC),
+    cv.Required(CONF_PIN): cv.All(pins.internal_gpio_output_pin_schema, valid_dac_pin),
+}).extend(cv.COMPONENT_SCHEMA)
+
+
+def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    yield cg.register_component(var, config)
+    yield output.register_output(var, config)
+
+    pin = yield cg.gpio_pin_expression(config[CONF_PIN])
+    cg.add(var.set_pin(pin))

tests/test1.yaml

@@ -1030,6 +1030,9 @@ output:
     id: dimmer1
     gate_pin: GPIO5
     zero_cross_pin: GPIO26
+  - platform: esp32_dac
+    pin: GPIO25
+    id: dac_output
 
 light:
   - platform: binary
@@ -1358,6 +1361,12 @@ switch:
     - output.set_level:
         id: gpio_19
         level: !lambda 'return 0.5;'
+    - output.set_level:
+        id: dac_output
+        level: 50%
+    - output.set_level:
+        id: dac_output
+        level: !lambda 'return 0.5;'
     turn_off_action:
     - switch.turn_on: living_room_lights_off
     restore_state: False