ESP32 ADC use factory calibration data (#2574)

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Otto Winter 2021-10-21 16:01:33 +02:00 committed by GitHub
parent 156104d5f5
commit cac5b356db
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3 changed files with 177 additions and 146 deletions

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@ -16,50 +16,6 @@ namespace adc {
static const char *const TAG = "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() { void ADCSensor::setup() {
ESP_LOGCONFIG(TAG, "Setting up ADC '%s'...", this->get_name().c_str()); ESP_LOGCONFIG(TAG, "Setting up ADC '%s'...", this->get_name().c_str());
#ifndef USE_ADC_SENSOR_VCC #ifndef USE_ADC_SENSOR_VCC
@ -67,15 +23,36 @@ void ADCSensor::setup() {
#endif #endif
#ifdef USE_ESP32 #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); adc1_config_width(ADC_WIDTH_BIT_12);
#if !CONFIG_IDF_TARGET_ESP32C3 && !CONFIG_IDF_TARGET_ESP32H2 if (!autorange_) {
adc_gpio_init(ADC_UNIT_1, (adc_channel_t) gpio_to_adc1(pin_->get_pin())); adc1_config_channel_atten(channel_, attenuation_);
#endif }
// 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
#endif // USE_ESP32
} }
void ADCSensor::dump_config() { void ADCSensor::dump_config() {
LOG_SENSOR("", "ADC Sensor", this); LOG_SENSOR("", "ADC Sensor", this);
#ifdef USE_ESP8266 #ifdef USE_ESP8266
@ -84,7 +61,8 @@ void ADCSensor::dump_config() {
#else #else
LOG_PIN(" Pin: ", pin_); LOG_PIN(" Pin: ", pin_);
#endif #endif
#endif #endif // USE_ESP8266
#ifdef USE_ESP32 #ifdef USE_ESP32
LOG_PIN(" Pin: ", pin_); LOG_PIN(" Pin: ", pin_);
if (autorange_) if (autorange_)
@ -106,101 +84,81 @@ void ADCSensor::dump_config() {
default: // This is to satisfy the unused ADC_ATTEN_MAX default: // This is to satisfy the unused ADC_ATTEN_MAX
break; break;
} }
#endif #endif // USE_ESP32
LOG_UPDATE_INTERVAL(this); LOG_UPDATE_INTERVAL(this);
} }
float ADCSensor::get_setup_priority() const { return setup_priority::DATA; } float ADCSensor::get_setup_priority() const { return setup_priority::DATA; }
void ADCSensor::update() { void ADCSensor::update() {
float value_v = this->sample(); float value_v = this->sample();
ESP_LOGD(TAG, "'%s': Got voltage=%.2fV", this->get_name().c_str(), value_v); ESP_LOGD(TAG, "'%s': Got voltage=%.2fV", this->get_name().c_str(), value_v);
this->publish_state(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_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() { float ADCSensor::sample() {
int raw = this->read_raw_(); #ifdef USE_ADC_SENSOR_VCC
uint32_t v = this->raw_to_microvolts_(raw); return ESP.getVcc() / 1024.0f; // NOLINT(readability-static-accessed-through-instance)
#ifdef USE_ESP32 #else
if (autorange_) { return analogRead(this->pin_->get_pin()) / 1024.0f; // NOLINT
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
}
#endif #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 #ifdef USE_ESP8266
std::string ADCSensor::unique_id() { return get_mac_address() + "-adc"; } std::string ADCSensor::unique_id() { return get_mac_address() + "-adc"; }
#endif #endif

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@ -8,6 +8,7 @@
#ifdef USE_ESP32 #ifdef USE_ESP32
#include "driver/adc.h" #include "driver/adc.h"
#include <esp_adc_cal.h>
#endif #endif
namespace esphome { namespace esphome {
@ -17,8 +18,9 @@ class ADCSensor : public sensor::Sensor, public PollingComponent, public voltage
public: public:
#ifdef USE_ESP32 #ifdef USE_ESP32
/// Set the attenuation for this pin. Only available on the ESP32. /// Set the attenuation for this pin. Only available on the ESP32.
void set_attenuation(adc_atten_t attenuation); void set_attenuation(adc_atten_t attenuation) { attenuation_ = attenuation; }
void set_autorange(bool autorange); void set_channel(adc1_channel_t channel) { channel_ = channel; }
void set_autorange(bool autorange) { autorange_ = autorange; }
#endif #endif
/// Update adc values. /// Update adc values.
@ -42,7 +44,9 @@ class ADCSensor : public sensor::Sensor, public PollingComponent, public voltage
#ifdef USE_ESP32 #ifdef USE_ESP32
adc_atten_t attenuation_{ADC_ATTEN_DB_0}; adc_atten_t attenuation_{ADC_ATTEN_DB_0};
adc1_channel_t channel_{};
bool autorange_{false}; bool autorange_{false};
esp_adc_cal_characteristics_t cal_characteristics_[(int) ADC_ATTEN_MAX] = {};
#endif #endif
}; };

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@ -6,12 +6,21 @@ from esphome.const import (
CONF_ATTENUATION, CONF_ATTENUATION,
CONF_ID, CONF_ID,
CONF_INPUT, CONF_INPUT,
CONF_NUMBER,
CONF_PIN, CONF_PIN,
DEVICE_CLASS_VOLTAGE, DEVICE_CLASS_VOLTAGE,
STATE_CLASS_MEASUREMENT, STATE_CLASS_MEASUREMENT,
UNIT_VOLT, UNIT_VOLT,
) )
from esphome.core import CORE from esphome.core import CORE
from esphome.components.esp32 import get_esp32_variant
from esphome.components.esp32.const import (
VARIANT_ESP32,
VARIANT_ESP32C3,
VARIANT_ESP32H2,
VARIANT_ESP32S2,
VARIANT_ESP32S3,
)
AUTO_LOAD = ["voltage_sampler"] AUTO_LOAD = ["voltage_sampler"]
@ -24,21 +33,77 @@ ATTENUATION_MODES = {
"auto": "auto", "auto": "auto",
} }
adc1_channel_t = cg.global_ns.enum("adc1_channel_t")
# From https://github.com/espressif/esp-idf/blob/master/components/driver/include/driver/adc_common.h
# pin to adc1 channel mapping
ESP32_VARIANT_ADC1_PIN_TO_CHANNEL = {
VARIANT_ESP32: {
36: adc1_channel_t.ADC1_CHANNEL_0,
37: adc1_channel_t.ADC1_CHANNEL_1,
38: adc1_channel_t.ADC1_CHANNEL_2,
39: adc1_channel_t.ADC1_CHANNEL_3,
32: adc1_channel_t.ADC1_CHANNEL_4,
33: adc1_channel_t.ADC1_CHANNEL_5,
34: adc1_channel_t.ADC1_CHANNEL_6,
35: adc1_channel_t.ADC1_CHANNEL_7,
},
VARIANT_ESP32S2: {
1: adc1_channel_t.ADC1_CHANNEL_0,
2: adc1_channel_t.ADC1_CHANNEL_1,
3: adc1_channel_t.ADC1_CHANNEL_2,
4: adc1_channel_t.ADC1_CHANNEL_3,
5: adc1_channel_t.ADC1_CHANNEL_4,
6: adc1_channel_t.ADC1_CHANNEL_5,
7: adc1_channel_t.ADC1_CHANNEL_6,
8: adc1_channel_t.ADC1_CHANNEL_7,
9: adc1_channel_t.ADC1_CHANNEL_8,
10: adc1_channel_t.ADC1_CHANNEL_9,
},
VARIANT_ESP32S3: {
1: adc1_channel_t.ADC1_CHANNEL_0,
2: adc1_channel_t.ADC1_CHANNEL_1,
3: adc1_channel_t.ADC1_CHANNEL_2,
4: adc1_channel_t.ADC1_CHANNEL_3,
5: adc1_channel_t.ADC1_CHANNEL_4,
6: adc1_channel_t.ADC1_CHANNEL_5,
7: adc1_channel_t.ADC1_CHANNEL_6,
8: adc1_channel_t.ADC1_CHANNEL_7,
9: adc1_channel_t.ADC1_CHANNEL_8,
10: adc1_channel_t.ADC1_CHANNEL_9,
},
VARIANT_ESP32C3: {
0: adc1_channel_t.ADC1_CHANNEL_0,
1: adc1_channel_t.ADC1_CHANNEL_1,
2: adc1_channel_t.ADC1_CHANNEL_2,
3: adc1_channel_t.ADC1_CHANNEL_3,
4: adc1_channel_t.ADC1_CHANNEL_4,
},
VARIANT_ESP32H2: {
0: adc1_channel_t.ADC1_CHANNEL_0,
1: adc1_channel_t.ADC1_CHANNEL_1,
2: adc1_channel_t.ADC1_CHANNEL_2,
3: adc1_channel_t.ADC1_CHANNEL_3,
4: adc1_channel_t.ADC1_CHANNEL_4,
},
}
def validate_adc_pin(value): def validate_adc_pin(value):
if str(value).upper() == "VCC": if str(value).upper() == "VCC":
return cv.only_on_esp8266("VCC") return cv.only_on_esp8266("VCC")
if CORE.is_esp32: if CORE.is_esp32:
from esphome.components.esp32 import is_esp32c3
value = pins.internal_gpio_input_pin_number(value) value = pins.internal_gpio_input_pin_number(value)
if is_esp32c3(): variant = get_esp32_variant()
if not (0 <= value <= 4): # ADC1 if variant not in ESP32_VARIANT_ADC1_PIN_TO_CHANNEL:
raise cv.Invalid("ESP32-C3: Only pins 0 though 4 support ADC.") raise cv.Invalid(f"This ESP32 variant ({variant}) is not supported")
elif not (32 <= value <= 39): # ADC1
raise cv.Invalid("ESP32: Only pins 32 though 39 support ADC.") if value not in ESP32_VARIANT_ADC1_PIN_TO_CHANNEL[variant]:
elif CORE.is_esp8266: raise cv.Invalid(f"{variant} doesn't support ADC on this pin")
return pins.internal_gpio_input_pin_schema(value)
if CORE.is_esp8266:
from esphome.components.esp8266.gpio import CONF_ANALOG from esphome.components.esp8266.gpio import CONF_ANALOG
value = pins.internal_gpio_pin_number({CONF_ANALOG: True, CONF_INPUT: True})( value = pins.internal_gpio_pin_number({CONF_ANALOG: True, CONF_INPUT: True})(
@ -50,10 +115,8 @@ def validate_adc_pin(value):
return pins.gpio_pin_schema( return pins.gpio_pin_schema(
{CONF_ANALOG: True, CONF_INPUT: True}, internal=True {CONF_ANALOG: True, CONF_INPUT: True}, internal=True
)(value) )(value)
else:
raise NotImplementedError
return pins.internal_gpio_input_pin_schema(value) raise NotImplementedError
adc_ns = cg.esphome_ns.namespace("adc") adc_ns = cg.esphome_ns.namespace("adc")
@ -97,3 +160,9 @@ async def to_code(config):
cg.add(var.set_autorange(cg.global_ns.true)) cg.add(var.set_autorange(cg.global_ns.true))
else: else:
cg.add(var.set_attenuation(config[CONF_ATTENUATION])) cg.add(var.set_attenuation(config[CONF_ATTENUATION]))
if CORE.is_esp32:
variant = get_esp32_variant()
pin_num = config[CONF_PIN][CONF_NUMBER]
chan = ESP32_VARIANT_ADC1_PIN_TO_CHANNEL[variant][pin_num]
cg.add(var.set_channel(chan))