PCA9685, fix reset device and add option EXTCLK (#3845)

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

esphome/components/pca9685/__init__.py

@@ -1,7 +1,7 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome.components import i2c
-from esphome.const import CONF_FREQUENCY, CONF_ID
+from esphome.const import CONF_FREQUENCY, CONF_ID, CONF_EXTERNAL_CLOCK_INPUT
 
 DEPENDENCIES = ["i2c"]
 MULTI_CONF = True
@@ -9,21 +9,39 @@ MULTI_CONF = True
 pca9685_ns = cg.esphome_ns.namespace("pca9685")
 PCA9685Output = pca9685_ns.class_("PCA9685Output", cg.Component, i2c.I2CDevice)
 
-CONFIG_SCHEMA = (
+
+def validate_frequency(config):
+    if config[CONF_EXTERNAL_CLOCK_INPUT]:
+        if CONF_FREQUENCY in config:
+            raise cv.Invalid(
+                "Frequency cannot be set when using an external clock input"
+            )
+        return config
+    if CONF_FREQUENCY not in config:
+        raise cv.Invalid("Frequency is required")
+    return config
+
+
+CONFIG_SCHEMA = cv.All(
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(PCA9685Output),
-            cv.Required(CONF_FREQUENCY): cv.All(
+            cv.Optional(CONF_FREQUENCY): cv.All(
                 cv.frequency, cv.Range(min=23.84, max=1525.88)
             ),
+            cv.Optional(CONF_EXTERNAL_CLOCK_INPUT, default=False): cv.boolean,
         }
     )
     .extend(cv.COMPONENT_SCHEMA)
-    .extend(i2c.i2c_device_schema(0x40))
+    .extend(i2c.i2c_device_schema(0x40)),
+    validate_frequency,
 )
 
 
 async def to_code(config):
-    var = cg.new_Pvariable(config[CONF_ID], config[CONF_FREQUENCY])
+    var = cg.new_Pvariable(config[CONF_ID])
+    if CONF_FREQUENCY in config:
+        cg.add(var.set_frequency(config[CONF_FREQUENCY]))
+    cg.add(var.set_extclk(config[CONF_EXTERNAL_CLOCK_INPUT]))
     await cg.register_component(var, config)
     await i2c.register_i2c_device(var, config)

esphome/components/pca9685/pca9685_output.cpp

@@ -21,6 +21,7 @@ static const uint8_t PCA9685_REGISTER_LED0 = 0x06;
 static const uint8_t PCA9685_REGISTER_PRE_SCALE = 0xFE;
 
 static const uint8_t PCA9685_MODE1_RESTART = 0b10000000;
+static const uint8_t PCA9685_MODE1_EXTCLK = 0b01000000;
 static const uint8_t PCA9685_MODE1_AUTOINC = 0b00100000;
 static const uint8_t PCA9685_MODE1_SLEEP = 0b00010000;
 
@@ -28,10 +29,13 @@ void PCA9685Output::setup() {
   ESP_LOGCONFIG(TAG, "Setting up PCA9685OutputComponent...");
 
   ESP_LOGV(TAG, "  Resetting devices...");
+  uint8_t address_tmp = this->address_;
+  this->set_i2c_address(0x00);
   if (!this->write_bytes(PCA9685_REGISTER_SOFTWARE_RESET, nullptr, 0)) {
     this->mark_failed();
     return;
   }
+  this->set_i2c_address(address_tmp);
 
   if (!this->write_byte(PCA9685_REGISTER_MODE1, PCA9685_MODE1_RESTART | PCA9685_MODE1_AUTOINC)) {
     this->mark_failed();
@@ -42,14 +46,6 @@ void PCA9685Output::setup() {
     return;
   }
 
-  int pre_scaler = static_cast<int>((25000000 / (4096 * this->frequency_)) - 1);
-  if (pre_scaler > 255)
-    pre_scaler = 255;
-  if (pre_scaler < 3)
-    pre_scaler = 3;
-
-  ESP_LOGV(TAG, "  -> Prescaler: %d", pre_scaler);
-
   uint8_t mode1;
   if (!this->read_byte(PCA9685_REGISTER_MODE1, &mode1)) {
     this->mark_failed();
@@ -60,6 +56,20 @@ void PCA9685Output::setup() {
     this->mark_failed();
     return;
   }
+
+  int pre_scaler = 3;
+  if (this->extclk_) {
+    mode1 = mode1 | PCA9685_MODE1_EXTCLK;
+    if (!this->write_byte(PCA9685_REGISTER_MODE1, mode1)) {
+      this->mark_failed();
+      return;
+    }
+  } else {
+    pre_scaler = static_cast<int>((25000000 / (4096 * this->frequency_)) - 1);
+    pre_scaler = clamp(pre_scaler, 3, 255);
+
+    ESP_LOGV(TAG, "  -> Prescaler: %d", pre_scaler);
+  }
   if (!this->write_byte(PCA9685_REGISTER_PRE_SCALE, pre_scaler)) {
     this->mark_failed();
     return;
@@ -78,7 +88,12 @@ void PCA9685Output::setup() {
 void PCA9685Output::dump_config() {
   ESP_LOGCONFIG(TAG, "PCA9685:");
   ESP_LOGCONFIG(TAG, "  Mode: 0x%02X", this->mode_);
-  ESP_LOGCONFIG(TAG, "  Frequency: %.0f Hz", this->frequency_);
+  if (this->extclk_) {
+    ESP_LOGCONFIG(TAG, "  EXTCLK: enabled");
+  } else {
+    ESP_LOGCONFIG(TAG, "  EXTCLK: disabled");
+    ESP_LOGCONFIG(TAG, "  Frequency: %.0f Hz", this->frequency_);
+  }
   if (this->is_failed()) {
     ESP_LOGE(TAG, "Setting up PCA9685 failed!");
   }

esphome/components/pca9685/pca9685_output.h

@@ -37,8 +37,7 @@ class PCA9685Channel : public output::FloatOutput {
 /// PCA9685 float output component.
 class PCA9685Output : public Component, public i2c::I2CDevice {
  public:
-  PCA9685Output(float frequency, uint8_t mode = PCA9685_MODE_OUTPUT_ONACK | PCA9685_MODE_OUTPUT_TOTEM_POLE)
+  PCA9685Output(uint8_t mode = PCA9685_MODE_OUTPUT_ONACK | PCA9685_MODE_OUTPUT_TOTEM_POLE) : mode_(mode) {}
-      : frequency_(frequency), mode_(mode) {}
 
   void register_channel(PCA9685Channel *channel);
 
@@ -46,6 +45,8 @@ class PCA9685Output : public Component, public i2c::I2CDevice {
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
   void loop() override;
+  void set_extclk(bool extclk) { this->extclk_ = extclk; }
+  void set_frequency(float frequency) { this->frequency_ = frequency; }
 
  protected:
   friend PCA9685Channel;
@@ -58,6 +59,7 @@ class PCA9685Output : public Component, public i2c::I2CDevice {
 
   float frequency_;
   uint8_t mode_;
+  bool extclk_ = false;
 
   uint8_t min_channel_{0xFF};
   uint8_t max_channel_{0x00};

esphome/const.py

@@ -219,6 +219,7 @@ CONF_EVENT = "event"
 CONF_EXPIRE_AFTER = "expire_after"
 CONF_EXPORT_ACTIVE_ENERGY = "export_active_energy"
 CONF_EXPORT_REACTIVE_ENERGY = "export_reactive_energy"
+CONF_EXTERNAL_CLOCK_INPUT = "external_clock_input"
 CONF_EXTERNAL_COMPONENTS = "external_components"
 CONF_EXTERNAL_VCC = "external_vcc"
 CONF_FALLING_EDGE = "falling_edge"