As3935 calibration (#5366)

esphome/components/as3935/as3935.cpp

@@ -21,6 +21,14 @@ void AS3935Component::setup() {
   this->write_mask_disturber(this->mask_disturber_);
   this->write_div_ratio(this->div_ratio_);
   this->write_capacitance(this->capacitance_);
+
+  // Handle setting up tuning or auto-calibration
+  if (this->tune_antenna_) {
+    ESP_LOGCONFIG(TAG, "  Antenna tuning: ENABLED - lightning detection will not function in this mode");
+    this->tune_antenna();
+  } else if (this->calibration_) {
+    this->calibrate_oscillator();
+  }
 }
 
 void AS3935Component::dump_config() {
@@ -227,6 +235,87 @@ uint32_t AS3935Component::get_lightning_energy_() {
   return pure_light;
 }
 
+// REG0x03, bit [7:6], manufacturer default: 0 (16 division ratio).
+// This function returns the current division ratio of the resonance frequency.
+// The antenna resonance frequency should be within 3.5 percent of 500kHz, and
+// so when modifying the resonance frequency with the internal capacitors
+// (tuneCap()) it's important to keep in mind that the displayed frequency on
+// the IRQ pin is divided by this number.
+uint8_t AS3935Component::read_div_ratio() {
+  ESP_LOGV(TAG, "Calling read_div_ratio");
+  uint8_t reg_val = this->read_register_(INT_MASK_ANT, DIV_MASK);
+  reg_val >>= 6;  // Front of the line.
+
+  if (reg_val == 0) {
+    return 16;
+  } else if (reg_val == 1) {
+    return 32;
+  } else if (reg_val == 2) {
+    return 64;
+  } else if (reg_val == 3) {
+    return 128;
+  }
+  ESP_LOGW(TAG, "Unknown response received for div_ratio");
+  return 0;
+}
+
+uint8_t AS3935Component::read_capacitance() {
+  ESP_LOGV(TAG, "Calling read_capacitance");
+  uint8_t reg_val = this->read_register_(FREQ_DISP_IRQ, CAP_MASK) * 8;
+  return (reg_val);
+}
+
+// REG0x08, bits [5,6,7], manufacturer default: 0.
+// This will send the frequency of the oscillators to the IRQ pin.
+//  _osc 1, bit[5] = TRCO - System RCO at 32.768kHz
+//  _osc 2, bit[6] = SRCO - Timer RCO Oscillators 1.1MHz
+//  _osc 3, bit[7] = LCO - Frequency of the Antenna
+void AS3935Component::display_oscillator(bool state, uint8_t osc) {
+  if ((osc < 1) || (osc > 3))
+    return;
+
+  this->write_register(FREQ_DISP_IRQ, OSC_MASK, state, 4 + osc);
+}
+
+// REG0x3D, bits[7:0]
+// This function calibrates both internal oscillators The oscillators are tuned
+// based on the resonance frequency of the antenna and so it should be trimmed
+// before the calibration is done.
+bool AS3935Component::calibrate_oscillator() {
+  ESP_LOGI(TAG, "Starting oscillators calibration...");
+  this->write_register(CALIB_RCO, WIPE_ALL, DIRECT_COMMAND, 0);  // Send command to calibrate the oscillators
+
+  this->display_oscillator(true, 2);
+  delay(2);  // Give time for the internal oscillators to start up.
+  this->display_oscillator(false, 2);
+
+  // Check it they were calibrated successfully.
+  uint8_t reg_val_srco = this->read_register_(CALIB_SRCO, CALIB_MASK_NOK);
+  uint8_t reg_val_trco = this->read_register_(CALIB_TRCO, CALIB_MASK_NOK);
+
+  // reg_val_srco &= CALIB_MASK;
+  // reg_val_srco >>= 6;
+  // reg_val_trco &= CALIB_MASK;
+  // reg_val_trco >>= 6;
+  if (!reg_val_srco && !reg_val_trco) {  // Zero upon success
+    ESP_LOGI(TAG, "Calibration was succesful");
+    return true;
+  } else {
+    ESP_LOGW(TAG, "Calibration was NOT succesful");
+    return false;
+  }
+}
+
+void AS3935Component::tune_antenna() {
+  ESP_LOGI(TAG, "Starting antenna tuning...");
+  uint8_t div_ratio = this->read_div_ratio();
+  uint8_t tune_val = this->read_capacitance();
+  ESP_LOGI(TAG, "Division Ratio is set to: %d", div_ratio);
+  ESP_LOGI(TAG, "Internal Capacitor is set to: %d", tune_val);
+  ESP_LOGI(TAG, "Displaying oscillator on INT pin. Measure its frequency - multiply value by Division Ratio");
+  this->display_oscillator(true, ANTFREQ);
+}
+
 uint8_t AS3935Component::read_register_(uint8_t reg, uint8_t mask) {
   uint8_t value = this->read_register(reg);
   value &= (~mask);