传感器偶尔跳值怎么办？用范围、迟滞和时间窗口处理

arduino-cli lib install 'Sensirion Core@0.7.3'
arduino-cli lib install --no-deps 'Sensirion I2C SHT4x@1.1.2'
arduino-cli compile --fqbn 'esp32:esp32:esp32s3:FlashSize=8M,PSRAM=opi,FlashMode=qio,PartitionScheme=default_8MB,CDCOnBoot=default,USBMode=hwcdc' .

// SPDX-License-Identifier: MIT
#pragma once
#include <stdint.h>
#include <math.h>
namespace quality {
enum class Flag { NO_DATA, VALID, CLIPPED_RH, STEP_CHANGE, TRANSPORT_ERROR, NON_FINITE, OUT_OF_RANGE, STALE };
enum class Alarm { UNKNOWN, OFF, ON };
inline const char* name(Flag q){switch(q){case Flag::NO_DATA:return "NO_DATA";case Flag::VALID:return "VALID";case Flag::CLIPPED_RH:return "CLIPPED_RH";case Flag::STEP_CHANGE:return "STEP_CHANGE";case Flag::TRANSPORT_ERROR:return "TRANSPORT_ERROR";case Flag::NON_FINITE:return "NON_FINITE";case Flag::OUT_OF_RANGE:return "OUT_OF_RANGE";case Flag::STALE:return "STALE";}return "?";}
inline const char* name(Alarm a){return a==Alarm::ON?"ON":a==Alarm::OFF?"OFF":"UNKNOWN";}
struct Point {uint32_t at;float t,rh;};
struct Model {
 static constexpr uint32_t STALE_MS=4500, WINDOW_MS=6500;
 Point window[4]{};uint8_t count=0;Flag flag=Flag::NO_DATA;Alarm alarm=Alarm::UNKNOWN;
 bool good=false,seen=false,usable=false;uint32_t last_good=0,last_seen=0;float raw_t=NAN,raw_rh=NAN,filtered_t=NAN,filtered_rh=NAN,previous_t=NAN,previous_rh=NAN;
 void invalidate(Flag f){flag=f;usable=false;count=0;filtered_t=filtered_rh=NAN;alarm=Alarm::UNKNOWN;}
 void tick(uint32_t now){if(seen && uint32_t(now-last_seen)>STALE_MS && flag!=Flag::STALE)invalidate(Flag::STALE);}
 int64_t age(uint32_t now)const{return good?int64_t(uint32_t(now-last_good)):-1;}
 void accept(uint32_t now,float t,float rh,int transport){
  // If a caller skipped tick(), enforce the same stale gap before considering recovery.
  tick(now);bool previous_usable=usable;uint32_t previous_at=last_good;
  seen=true;last_seen=now;raw_t=t;raw_rh=rh;
  if(transport){invalidate(Flag::TRANSPORT_ERROR);return;}
  if(!isfinite(t)||!isfinite(rh)){invalidate(Flag::NON_FINITE);return;}
  // SHT4x conversion supports raw RH -6..119; clamp only the displayed RH.
  if(t < -40 || t > 125 || rh < -6 || rh > 119){invalidate(Flag::OUT_OF_RANGE);return;}
  bool step=previous_usable && uint32_t(now-previous_at)<=3000 && (fabsf(t-previous_t)>5 || fabsf(rh-previous_rh)>20);
  if(step)count=0; // preserve the real new value; do not silently discard a possible true change
  uint8_t keep=0;for(uint8_t i=0;i<count;i++)if(uint32_t(now-window[i].at)<=WINDOW_MS)window[keep++]=window[i];count=keep;
  if(count==4){for(uint8_t i=1;i<4;i++)window[i-1]=window[i];count=3;}
  float shown=fminf(100,fmaxf(0,rh));window[count++]={now,t,shown};float st=0,sr=0;for(uint8_t i=0;i<count;i++){st+=window[i].t;sr+=window[i].rh;}filtered_t=st/count;filtered_rh=sr/count;
  flag=step?Flag::STEP_CHANGE:(shown!=rh?Flag::CLIPPED_RH:Flag::VALID);usable=true;good=true;last_good=now;previous_t=t;previous_rh=rh;
  // Hysteresis uses validated RAW temperature, not the smoothed trend.
  if(t>=30)alarm=Alarm::ON;else if(t<=28)alarm=Alarm::OFF;
 }
};
}

// SPDX-License-Identifier: MIT
// S08: fixed SHT40 sensor path and explicitly labelled fault fixture.
#include <Arduino.h>
#include <Wire.h>
#include <SensirionI2cSht4x.h>
#include "quality_model.h"
SensirionI2cSht4x sensor;
quality::Model model;
constexpr uint8_t SDA_PIN=8,SCL_PIN=9;
constexpr uint32_t PERIOD_MS=2000;
bool busReady=false,fixture=false;uint32_t sampled=0,sequence=0,fixtureStep=0;
quality::Flag reported=quality::Flag::NO_DATA;
bool startBus(){bool ok=Wire.begin(SDA_PIN,SCL_PIN,100000);Wire.setTimeOut(20);sensor.begin(Wire,SHT40_I2C_ADDR_44);return ok;}
void report(uint32_t now,int error,bool acquired=true){
 char errorText[16]="NA";if(acquired)snprintf(errorText,sizeof errorText,"%d",error);
 Serial.printf("seq=%lu uptime_ms=%lu source=%s kind=%s error=%s raw_age_ms=%lld raw_T=%.2f raw_RH=%.2f quality=%s usable=%u trend_T=%.2f trend_RH=%.2f count=%u alarm=%s last_good_age_ms=%lld\n",
 (unsigned long)++sequence,(unsigned long)now,fixture?"FIXTURE":"SENSOR",acquired?"SAMPLE":"STATUS",errorText,model.seen?(long long)uint32_t(now-model.last_seen):-1LL,model.raw_t,model.raw_rh,quality::name(model.flag),model.usable,model.filtered_t,model.filtered_rh,model.count,quality::name(model.alarm),(long long)model.age(now));
 reported=model.flag;
}
void setup(){Serial.begin(115200);busReady=startBus();sampled=millis();Serial.println("S08 core=3.3.12 SHT4x=1.1.2 Core=0.7.3 SDA8 SCL9 0x44; f=fixture r=real; nan trend means unavailable");}
void loop(){
 for(unsigned n=0;n<8 && Serial.available();++n){int c=Serial.read();if(c=='f'||c=='r'){fixture=c=='f';model=quality::Model{};fixtureStep=0;sampled=millis();reported=quality::Flag::NO_DATA;Serial.printf("MODE_RESET source=%s; no retained filter or alarm\n",fixture?"FIXTURE":"SENSOR");}}
 uint32_t now=millis();model.tick(now);if(model.flag!=reported)report(now,0,false);
 if(uint32_t(now-sampled)>=PERIOD_MS){
  sampled=now;float t=NAN,rh=NAN;int16_t error=0;bool acquire=true;
  if(fixture){
   // 2 s slots. Four skipped slots exercise >4.5 s stale without inventing a sensor value.
   const float temps[]={22,22.2f,NAN,22,22,22,22,22,22,22,40,40,29,28,31};
   uint32_t k=fixtureStep++%15;rh=50;t=temps[k];if(k==3)error=-1;if(k>=5&&k<=8)acquire=false;
  }else{if(!busReady)busReady=startBus();if(busReady)error=sensor.measureHighPrecision(t,rh);else error=-1;}
  if(acquire){model.accept(now,t,rh,error);report(now,error);}
 }
 delay(1);
}

c++ -std=c++17 -Wall -Wextra -Werror host/host_check.cpp -o /tmp/s08-host
/tmp/s08-host