ego.cpp

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/**
 * @author Andrey Belomutskiy, (c) 2012-2020
 *
 * EGO Exhaust Gas Oxygen, also known as AFR Air/Fuel Ratio :) connectet over analog input
 *
 */
#include "pch.h"
 
StoredValueSensor smoothedLambda1Sensor(SensorType::SmoothedLambda1, MS2NT(500));
StoredValueSensor smoothedLambda2Sensor(SensorType::SmoothedLambda2, MS2NT(500));
 
ExpAverage expAverageLambda1;
ExpAverage expAverageLambda2;
 
#include "cyclic_buffer.h"
 
bool hasAfrSensor() {
    if (engineConfiguration->enableAemXSeries) {
        return true;
    }
 
    return isAdcChannelValid(engineConfiguration->afr.hwChannel);
}
 
float getAfr(SensorType type) {
    afr_sensor_s * sensor = &engineConfiguration->afr;
 
    if (!isAdcChannelValid(type == SensorType::Lambda1 ? engineConfiguration->afr.hwChannel : engineConfiguration->afr.hwChannel2)) {
        return 0;
    }
 
    auto volts = adcGetScaledVoltage("ego", type == SensorType::Lambda1 ? sensor->hwChannel : sensor->hwChannel2);
 
    float interpolatedAfr = interpolateMsg("AFR", sensor->v1, sensor->value1, sensor->v2, sensor->value2, volts.value_or(0));
 
    switch (type) {
        case SensorType::Lambda1: {
            expAverageLambda1.setSmoothingFactor(engineConfiguration->afrExpAverageAlpha);
            smoothedLambda1Sensor.setValidValue(expAverageLambda1.initOrAverage(interpolatedAfr), getTimeNowNt());
            break;
        }
        case SensorType::Lambda2: {
            expAverageLambda2.setSmoothingFactor(engineConfiguration->afrExpAverageAlpha);
            smoothedLambda2Sensor.setValidValue(expAverageLambda2.initOrAverage(interpolatedAfr), getTimeNowNt());
            break;
        }
        default:
            break;
    }
 
    return interpolateMsg("AFR", sensor->v1, sensor->value1, sensor->v2, sensor->value2, volts.value_or(0))
            + engineConfiguration->egoValueShift;
}
 
// this method is only used for canned tunes now! User-facing selection is defined in tunerstudio.template.ini using settingSelector
static void initEgoSensor(afr_sensor_s *sensor, ego_sensor_e type) {
 
    switch (type) {
    case ES_BPSX_D1:
        /**
         * This decodes BPSX D1 Wideband Controller analog signal
         */
        sensor->v1 = 0;
        sensor->value1 = 9;
        sensor->v2 = 5;
        sensor->value2 = 19;
        break;
 
    case ES_Innovate_MTX_L:
        sensor->v1 = 0;
        sensor->value1 = 7.35;
        sensor->v2 = 5;
        sensor->value2 = 22.39;
        break;
    case ES_14Point7_Free:
        sensor->v1 = 0;
        sensor->value1 = 9.996;
        sensor->v2 = 5;
        sensor->value2 = 19.992;
        break;
        // technically 14Point7 and PLX use the same scale
    case ES_PLX:
        sensor->v1 = 0;
        sensor->value1 = 10;
        sensor->v2 = 5;
        sensor->value2 = 20;
        break;
    case ES_AEM:
        sensor->v1 = 0.5;
        sensor->value1 = 8.5;
        sensor->v2 = 4.5;
        sensor->value2 = 18;
        break;
    default:
        firmwareError(ObdCode::CUSTOM_EGO_TYPE, "Unexpected EGO %d", type);
        break;
    }
}
 
void setEgoSensor(ego_sensor_e type) {
    engineConfiguration->afr_type = type;
    initEgoSensor(&engineConfiguration->afr, type);
}