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bugfix(adc): use calibration data #70

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Merged
finger563 merged 1 commit into from
Jun 20, 2023
Merged

bugfix(adc): use calibration data #70

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80 changes: 75 additions & 5 deletions components/adc/include/continuous_adc.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
#include <optional>
#include <unordered_map>

#include "esp_adc/adc_cali.h"
#include "esp_adc/adc_cali_scheme.h"
#include "esp_adc/adc_continuous.h"

#include "adc_types.hpp"
Expand Down Expand Up @@ -49,7 +51,9 @@ class ContinuousAdc {
ContinuousAdc(const Config &config)
: sample_rate_hz_(config.sample_rate_hz), window_size_bytes_(config.window_size_bytes),
num_channels_(config.channels.size()), conv_mode_(config.convert_mode),
logger_({.tag = "Continuous Adc", .level = config.log_level}) {
logger_({.tag = "Continuous Adc",
.rate_limit = std::chrono::milliseconds(100),
.level = config.log_level}) {
// initialize the adc continuous subsystem
init(config.channels);
// allocate memory for the task to store result data from DMA
Expand All @@ -76,6 +80,14 @@ class ContinuousAdc {
delete[] result_data_;
ESP_ERROR_CHECK(adc_continuous_stop(handle_));
ESP_ERROR_CHECK(adc_continuous_deinit(handle_));
// clean up the calibration data
for (auto &channel : channels_) {
#if ADC_CALI_SCHEME_CURVE_FITTING_SUPPORTED
ESP_ERROR_CHECK(adc_cali_delete_scheme_curve_fitting(cali_handles_[channel]));
#elif ADC_CALI_SCHEME_LINE_FITTING_SUPPORTED
ESP_ERROR_CHECK(adc_cali_delete_scheme_line_fitting(cali_handles_[channel]));
#endif
}
}

/**
Expand Down Expand Up @@ -171,19 +183,22 @@ class ContinuousAdc {
{
std::lock_guard<std::mutex> lk(data_mutex_);
for (auto &channel : channels_) {
logger_.debug("CH{} - {} , {}", (int)channel, sums_[channel], num_samples_[channel]);
float num_samples = num_samples_[channel];
if (num_samples > 0) {
float sum = sums_[channel];
// note: the data collected above is uncalibrated (raw) values so we need to convert
// to millivolts
// TODO: use ESP32 hardware-accelerated filter
// simple filter
values_[channel] = sum / num_samples;
int millivolts = 0;
adc_cali_raw_to_voltage(cali_handles_[channel], sum / num_samples, &millivolts);
values_[channel] = float(millivolts);
actual_rates_[channel] = num_samples / elapsed_seconds;
}
logger_.debug_rate_limited("CH{} - {}, {}, {:.2f}, {:.2f}", (int)channel, sums_[channel],
num_samples_[channel], values_[channel], actual_rates_[channel]);
}
}
// TODO: if the elapsed_seconds is too small, we may want to delay to
// prevent task starvation...

// don't want to stop the task
return false;
Expand Down Expand Up @@ -245,6 +260,12 @@ class ContinuousAdc {
logger_.info("adc_pattern[{}].channel is 0x{:02x}", i, (int)adc_pattern[i].channel);
logger_.info("adc_pattern[{}].unit is 0x{:02x}", i, (int)adc_pattern[i].unit);

// create the calibration data
auto calibrated =
init_calibration(conf.unit, conf.attenuation, (adc_bitwidth_t)adc_pattern[i].bit_width,
&cali_handles_[conf.channel]);
logger_.info("adc_pattern[{}].cali_handle is calibrated: {}", i, calibrated);

// save the channel
channels_.push_back(conf.channel);
// update our dictionaries
Expand All @@ -263,6 +284,54 @@ class ContinuousAdc {
ESP_ERROR_CHECK(adc_continuous_start(handle_));
}

bool init_calibration(adc_unit_t unit, adc_atten_t atten, adc_bitwidth_t bitwidth,
adc_cali_handle_t *out_handle) {
adc_cali_handle_t handle = NULL;
esp_err_t ret = ESP_FAIL;
bool calibrated = false;

#if ADC_CALI_SCHEME_CURVE_FITTING_SUPPORTED
if (!calibrated) {
logger_.info("calibration scheme version is {}", "Curve Fitting");
adc_cali_curve_fitting_config_t cali_config = {
.unit_id = unit,
.atten = atten,
.bitwidth = bitwidth,
};
ret = adc_cali_create_scheme_curve_fitting(&cali_config, &handle);
if (ret == ESP_OK) {
calibrated = true;
}
}
#endif

#if ADC_CALI_SCHEME_LINE_FITTING_SUPPORTED
if (!calibrated) {
logger_.info("calibration scheme version is {}", "Line Fitting");
adc_cali_line_fitting_config_t cali_config = {
.unit_id = unit,
.atten = atten,
.bitwidth = bitwidth,
};
ret = adc_cali_create_scheme_line_fitting(&cali_config, &handle);
if (ret == ESP_OK) {
calibrated = true;
}
}
#endif

*out_handle = handle;
if (ret == ESP_OK) {
logger_.info("Calibration Success");
} else if (ret == ESP_ERR_NOT_SUPPORTED || !calibrated) {
logger_.warn("eFuse not burnt, skip software calibration");
} else {
logger_.error("Invalid arg or no memory");
}

return calibrated;
}

static bool IRAM_ATTR s_conv_done_cb(adc_continuous_handle_t handle,
const adc_continuous_evt_data_t *edata, void *user_data) {
BaseType_t mustYield = pdFALSE;
Expand All @@ -286,6 +355,7 @@ class ContinuousAdc {
std::mutex data_mutex_;
uint8_t *result_data_;
std::vector<adc_channel_t> channels_;
std::unordered_map<adc_channel_t, adc_cali_handle_t> cali_handles_;
std::unordered_map<adc_channel_t, size_t> sums_;
std::unordered_map<adc_channel_t, size_t> num_samples_;
std::unordered_map<adc_channel_t, float> values_;
Expand Down