Add X9C Potentiometer component (#4183)

fixes https://github.com/esphome/feature-requests/issues/1270

esphome/components/x9c/x9c.cpp

@@ -0,0 +1,72 @@
+#include "x9c.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace x9c {
+
+static const char *const TAG = "x9c.output";
+
+void X9cOutput::trim_value(int change_amount) {
+  if (change_amount > 0) {  // Set change direction
+    this->ud_pin_->digital_write(true);
+  } else {
+    this->ud_pin_->digital_write(false);
+  }
+
+  this->inc_pin_->digital_write(true);
+  this->cs_pin_->digital_write(false);  // Select chip
+
+  for (int i = 0; i < abs(change_amount); i++) {  // Move wiper
+    this->inc_pin_->digital_write(true);
+    delayMicroseconds(1);
+    this->inc_pin_->digital_write(false);
+    delayMicroseconds(1);
+  }
+
+  delayMicroseconds(100);  // Let value settle
+
+  this->inc_pin_->digital_write(false);
+  this->cs_pin_->digital_write(true);  // Deselect chip safely (no save)
+}
+
+void X9cOutput::setup() {
+  ESP_LOGCONFIG(TAG, "Setting up X9C Potentiometer with initial value of %f", this->initial_value_);
+
+  this->inc_pin_->get_pin();
+  this->inc_pin_->setup();
+  this->inc_pin_->digital_write(false);
+
+  this->cs_pin_->get_pin();
+  this->cs_pin_->setup();
+  this->cs_pin_->digital_write(true);
+
+  this->ud_pin_->get_pin();
+  this->ud_pin_->setup();
+
+  if (this->initial_value_ <= 0.50) {
+    this->trim_value(-101);  // Set min value (beyond 0)
+    this->trim_value((int) (this->initial_value_ * 100));
+  } else {
+    this->trim_value(101);  // Set max value (beyond 100)
+    this->trim_value((int) (this->initial_value_ * 100) - 100);
+  }
+  this->pot_value_ = this->initial_value_;
+  this->write_state(this->initial_value_);
+}
+
+void X9cOutput::write_state(float state) {
+  this->trim_value((int) ((state - this->pot_value_) * 100));
+  this->pot_value_ = state;
+}
+
+void X9cOutput::dump_config() {
+  ESP_LOGCONFIG(TAG, "X9C Potentiometer Output:");
+  LOG_PIN("  Chip Select Pin: ", this->cs_pin_);
+  LOG_PIN("  Increment Pin: ", this->inc_pin_);
+  LOG_PIN("  Up/Down Pin: ", this->ud_pin_);
+  ESP_LOGCONFIG(TAG, "  Initial Value: %f", this->initial_value_);
+  LOG_FLOAT_OUTPUT(this);
+}
+
+}  // namespace x9c
+}  // namespace esphome