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Code Issues Releases Wiki Activity

ESP32 ADC use factory calibration data (#2574)

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This commit is contained in:
Otto Winter
2021-10-21 16:01:33 +02:00
committed by GitHub
parent 156104d5f5
commit cac5b356db
3 changed files with 177 additions and 146 deletions
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224
esphome/components/adc/adc_sensor.cpp
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@@ -16,50 +16,6 @@ namespace adc {
static const char *const TAG = "adc";
#ifdef USE_ESP32
inline adc1_channel_t gpio_to_adc1(uint8_t pin) {
#if CONFIG_IDF_TARGET_ESP32
switch (pin) {
case 36:
return ADC1_CHANNEL_0;
case 37:
return ADC1_CHANNEL_1;
case 38:
return ADC1_CHANNEL_2;
case 39:
return ADC1_CHANNEL_3;
case 32:
return ADC1_CHANNEL_4;
case 33:
return ADC1_CHANNEL_5;
case 34:
return ADC1_CHANNEL_6;
case 35:
return ADC1_CHANNEL_7;
default:
return ADC1_CHANNEL_MAX;
}
#elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32H2
switch (pin) {
case 0:
return ADC1_CHANNEL_0;
case 1:
return ADC1_CHANNEL_1;
case 2:
return ADC1_CHANNEL_2;
case 3:
return ADC1_CHANNEL_3;
case 4:
return ADC1_CHANNEL_4;
default:
return ADC1_CHANNEL_MAX;
}
#endif
}
void ADCSensor::set_attenuation(adc_atten_t attenuation) { this->attenuation_ = attenuation; }
void ADCSensor::set_autorange(bool autorange) { this->autorange_ = autorange; }
#endif
void ADCSensor::setup() {
ESP_LOGCONFIG(TAG, "Setting up ADC '%s'...", this->get_name().c_str());
#ifndef USE_ADC_SENSOR_VCC
@@ -67,15 +23,36 @@ void ADCSensor::setup() {
#endif
#ifdef USE_ESP32
if (this->autorange_)
this->attenuation_ = ADC_ATTEN_DB_11;
adc1_config_channel_atten(gpio_to_adc1(pin_->get_pin()), attenuation_);
adc1_config_width(ADC_WIDTH_BIT_12);
#if !CONFIG_IDF_TARGET_ESP32C3 && !CONFIG_IDF_TARGET_ESP32H2
adc_gpio_init(ADC_UNIT_1, (adc_channel_t) gpio_to_adc1(pin_->get_pin()));
#endif
if (!autorange_) {
adc1_config_channel_atten(channel_, attenuation_);
}
// load characteristics for each attenuation
for (int i = 0; i < (int) ADC_ATTEN_MAX; i++) {
auto cal_value = esp_adc_cal_characterize(ADC_UNIT_1, (adc_atten_t) i, ADC_WIDTH_BIT_12,
1100, // default vref
&cal_characteristics_[i]);
switch (cal_value) {
case ESP_ADC_CAL_VAL_EFUSE_VREF:
ESP_LOGV(TAG, "Using eFuse Vref for calibration");
break;
case ESP_ADC_CAL_VAL_EFUSE_TP:
ESP_LOGV(TAG, "Using two-point eFuse Vref for calibration");
break;
case ESP_ADC_CAL_VAL_DEFAULT_VREF:
default:
break;
}
}
// adc_gpio_init doesn't exist on ESP32-C3 or ESP32-H2
#if !defined(USE_ESP32_VARIANT_ESP32C3) && !defined(USE_ESP32_VARIANT_ESP32H2)
adc_gpio_init(ADC_UNIT_1, (adc_channel_t) channel_);
#endif
#endif // USE_ESP32
}
void ADCSensor::dump_config() {
LOG_SENSOR("", "ADC Sensor", this);
#ifdef USE_ESP8266
@@ -84,7 +61,8 @@ void ADCSensor::dump_config() {
#else
LOG_PIN(" Pin: ", pin_);
#endif
#endif
#endif // USE_ESP8266
#ifdef USE_ESP32
LOG_PIN(" Pin: ", pin_);
if (autorange_)
@@ -106,101 +84,81 @@ void ADCSensor::dump_config() {
default: // This is to satisfy the unused ADC_ATTEN_MAX
break;
}
#endif
#endif // USE_ESP32
LOG_UPDATE_INTERVAL(this);
}
float ADCSensor::get_setup_priority() const { return setup_priority::DATA; }
void ADCSensor::update() {
float value_v = this->sample();
ESP_LOGD(TAG, "'%s': Got voltage=%.2fV", this->get_name().c_str(), value_v);
this->publish_state(value_v);
}
uint16_t ADCSensor::read_raw_() {
#ifdef USE_ESP32
return adc1_get_raw(gpio_to_adc1(pin_->get_pin()));
#endif
#ifdef USE_ESP8266
#ifdef USE_ADC_SENSOR_VCC
return ESP.getVcc(); // NOLINT(readability-static-accessed-through-instance)
#else
return analogRead(this->pin_->get_pin()); // NOLINT
#endif
#endif
}
uint32_t ADCSensor::raw_to_microvolts_(uint16_t raw) {
#ifdef USE_ESP32
#if CONFIG_IDF_TARGET_ESP32
switch (this->attenuation_) {
case ADC_ATTEN_DB_0:
return raw * 269; // 1e6 * 1.1 / 4095
case ADC_ATTEN_DB_2_5:
return raw * 366; // 1e6 * 1.5 / 4095
case ADC_ATTEN_DB_6:
return raw * 537; // 1e6 * 2.2 / 4095
case ADC_ATTEN_DB_11:
return raw * 952; // 1e6 * 3.9 / 4095
default: // This is to satisfy the unused ADC_ATTEN_MAX
return raw * 244; // 1e6 * 1.0 / 4095
}
#elif CONFIG_IDF_TARGET_ESP32C3 || CONFIG_IDF_TARGET_ESP32H2
switch (this->attenuation_) {
case ADC_ATTEN_DB_0:
return raw * 205; // 1e6 * 0.84 / 4095
case ADC_ATTEN_DB_2_5:
return raw * 276; // 1e6 * 1.13 / 4095
case ADC_ATTEN_DB_6:
return raw * 381; // 1e6 * 1.56 / 4095
case ADC_ATTEN_DB_11:
return raw * 733; // 1e6 * 3.0 / 4095
default: // This is to satisfy the unused ADC_ATTEN_MAX
return raw * 244; // 1e6 * 1.0 / 4095
}
#endif
#endif
#ifdef USE_ESP8266
return raw * 977; // 1e6 / 1024
#endif
}
float ADCSensor::sample() {
int raw = this->read_raw_();
uint32_t v = this->raw_to_microvolts_(raw);
#ifdef USE_ESP32
if (autorange_) {
int raw11 = raw, raw6 = 4095, raw2 = 4095, raw0 = 4095;
uint32_t v11 = v, v6 = 0, v2 = 0, v0 = 0;
if (raw11 < 4095) { // Progressively read all attenuation ranges
adc1_config_channel_atten(gpio_to_adc1(pin_->get_pin()), ADC_ATTEN_DB_6);
raw6 = this->read_raw_();
v6 = this->raw_to_microvolts_(raw6);
if (raw6 < 4095) {
adc1_config_channel_atten(gpio_to_adc1(pin_->get_pin()), ADC_ATTEN_DB_2_5);
raw2 = this->read_raw_();
v2 = this->raw_to_microvolts_(raw2);
if (raw2 < 4095) {
adc1_config_channel_atten(gpio_to_adc1(pin_->get_pin()), ADC_ATTEN_DB_0);
raw0 = this->read_raw_();
v0 = this->raw_to_microvolts_(raw0);
}
}
adc1_config_channel_atten(gpio_to_adc1(pin_->get_pin()), ADC_ATTEN_DB_11);
} // Contribution coefficients (normalized to 2048)
uint16_t c11 = clamp(raw11, 0, 2048); // high 1, middle 1, low 0
uint16_t c6 = (2048 - abs(raw6 - 2048)); // high 0, middle 1, low 0
uint16_t c2 = (2048 - abs(raw2 - 2048)); // high 0, middle 1, low 0
uint16_t c0 = clamp(4095 - raw0, 0, 2048); // high 0, middle 1, low 1
uint32_t csum = c11 + c6 + c2 + c0; // sum to normalize the final result
if (csum > 0)
v = (v11 * c11) + (v6 * c6) + (v2 * c2) + (v0 * c0);
else // in case of error, this keeps the 11db output (v)
csum = 1;
csum *= 1e6; // include the 1e6 microvolts->volts conversion factor
return (float) v / (float) csum; // normalize, convert & return
}
#ifdef USE_ADC_SENSOR_VCC
return ESP.getVcc() / 1024.0f; // NOLINT(readability-static-accessed-through-instance)
#else
return analogRead(this->pin_->get_pin()) / 1024.0f; // NOLINT
#endif
return v / (float) 1e6; // convert from microvolts to volts
}
#endif
#ifdef USE_ESP32
float ADCSensor::sample() {
if (!autorange_) {
int raw = adc1_get_raw(channel_);
if (raw == -1) {
return NAN;
}
uint32_t mv = esp_adc_cal_raw_to_voltage(raw, &cal_characteristics_[(int) attenuation_]);
return mv / 1000.0f;
}
int raw11, raw6 = 4095, raw2 = 4095, raw0 = 4095;
adc1_config_channel_atten(channel_, ADC_ATTEN_DB_11);
raw11 = adc1_get_raw(channel_);
if (raw11 < 4095) {
adc1_config_channel_atten(channel_, ADC_ATTEN_DB_6);
raw6 = adc1_get_raw(channel_);
if (raw6 < 4095) {
adc1_config_channel_atten(channel_, ADC_ATTEN_DB_2_5);
raw2 = adc1_get_raw(channel_);
if (raw2 < 4095) {
adc1_config_channel_atten(channel_, ADC_ATTEN_DB_0);
raw0 = adc1_get_raw(channel_);
}
}
}
if (raw0 == -1 || raw2 == -1 || raw6 == -1 || raw11 == -1) {
return NAN;
}
// prevent divide by zero
if (raw0 == 0 && raw2 == 0 && raw6 == 0 && raw11 == 0) {
return 0;
}
uint32_t mv11 = esp_adc_cal_raw_to_voltage(raw11, &cal_characteristics_[(int) ADC_ATTEN_DB_11]);
uint32_t mv6 = esp_adc_cal_raw_to_voltage(raw6, &cal_characteristics_[(int) ADC_ATTEN_DB_6]);
uint32_t mv2 = esp_adc_cal_raw_to_voltage(raw2, &cal_characteristics_[(int) ADC_ATTEN_DB_2_5]);
uint32_t mv0 = esp_adc_cal_raw_to_voltage(raw0, &cal_characteristics_[(int) ADC_ATTEN_DB_0]);
// Contribution of each value, in range 0-2048
uint32_t c11 = std::min(raw11, 2048);
uint32_t c6 = 2048 - std::abs(raw6 - 2048);
uint32_t c2 = 2048 - std::abs(raw2 - 2048);
uint32_t c0 = std::min(4095 - raw0, 2048);
// max theoretical csum value is 2048*4 = 8192
uint32_t csum = c11 + c6 + c2 + c0;
// each mv is max 3900; so max value is 3900*2048*4, fits in unsigned
uint32_t mv_scaled = (mv11 * c11) + (mv6 * c6) + (mv2 * c2) + (mv0 * c0);
return mv_scaled / (float) (csum * 1000U);
}
#endif // USE_ESP32
#ifdef USE_ESP8266
std::string ADCSensor::unique_id() { return get_mac_address() + "-adc"; }
#endif