Cảnh Báo Trẻ Trong Xe

// Wiring verified: modem software UART RX8 TX9; DHT D2; LED D4/D5; buzzer D6; I2C A4/A5.
#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_CCS811.h>
#include <DHT.h>
#include <AltSoftSerial.h>
// Dien so nguoi giam ho theo dang +84...; de trong se KHONG goi/gui SMS.
const char PHONE[] = "+84396869634";
const uint16_t LEVEL1_PPM=1000, LEVEL2_PPM=2000, LEVEL3_PPM=5000;
const uint8_t LED1=4, LED2=5, BUZZ=6;
DHT dht(2,DHT11);
Adafruit_CCS811 gas;
AltSoftSerial modem; // Uno RX D8, TX D9
uint16_t eco2=0;
float temp=NAN;
bool gasOK=false, gasValid=false, tempValid=false;
uint32_t lastRead=0, lastGas=0, lastTemp=0, nextInit=15000;
uint32_t lastSMS=0,lastCall=0, started=0;
bool smsEver=false,callEver=false;
uint8_t level=0,initStep=0;
// Modem state: 0 init, 1 idle, 2 SMS prompt, 3 SMS result, 4 calling, 5 hangup
uint8_t state=0;
char response[140]; uint8_t used=0;
bool gotOK=false,gotError=false,prompt=false,sent=false;
void clearReply(){used=0;response[0]=0;gotOK=gotError=prompt=sent=false;}
void command(const __FlashStringHelper* s){clearReply();modem.println(s);started=millis();}
bool due(uint32_t now,uint32_t then,uint32_t interval){return (uint32_t)(now-then)>=interval;}
void receive(){
 while(modem.available()){
  char c=modem.read(); if(c=='>')prompt=true;
  if(c=='\n'){
   response[used]=0;
   if(strstr(response,"OK"))gotOK=true;
   if(strstr(response,"ERROR"))gotError=true;
   if(strstr(response,"+CMGS:"))sent=true;
   used=0;
  } else if(c!='\r' && used<sizeof(response)-1)response[used++]=c;
 }
}
void sample(uint32_t now){
 // DHT library takes a short synchronous reading; no delay-based alarm timing.
 if(!due(now,lastRead,2000))return;
 lastRead=now;
 float t=dht.readTemperature(), h=dht.readHumidity();
 if(!isnan(t)){temp=t;lastTemp=now;tempValid=true;}
 if(gasOK && gas.available() && gas.readData()==0){eco2=gas.geteCO2();lastGas=now;gasValid=true;}
 if(gasOK && !isnan(t) && !isnan(h))gas.setEnvironmentalData(h,t);
 Serial.print(F("eCO2="));Serial.print(eco2);Serial.print(F(" T="));Serial.println(temp);
}
void alarms(uint32_t now){
 bool gv=gasValid&&!due(now,lastGas,10000),tv=tempValid&&!due(now,lastTemp,10000);
 level=0;
 if(gv&&eco2>=LEVEL1_PPM)level=1;
 if((gv&&eco2>=LEVEL2_PPM)||(tv&&temp>40))level=2;
 if((gv&&eco2>=LEVEL3_PPM)||(tv&&temp>=42))level=3;
 bool fault=now>30000&&(!gv||!tv);
 digitalWrite(LED1,level>=1 || (fault&&now%1000<500));
 digitalWrite(LED2,level>=2 || (fault&&now%1000>=500));
 bool sound=level==3 || (level==2&&now%300<150) || (level==1&&now%1000<200);
 if(fault && !level)sound=now%5000<100;
 digitalWrite(BUZZ,sound);
}
void startCall(uint32_t now){
 clearReply(); modem.print(F("ATD"));modem.print(PHONE);modem.println(';');
 lastCall=now;callEver=true;started=now;state=4;
}
void network(uint32_t now){
 receive();
 if(state==0){
  if((int32_t)(now-nextInit)<0)return;
  if(initStep==0){modem.end();modem.begin(115200);command(F("AT"));initStep=1;return;}
  if(initStep==2){modem.end();modem.begin(9600);command(F("ATE0"));initStep=3;return;}
  if(gotError||due(now,started,3000)){initStep=0;nextInit=now+3000;return;}
  if(!gotOK)return;
  switch(initStep){
   case 1:command(F("AT+IPR=9600"));initStep=2;nextInit=now+300;return;
   case 2:modem.end();modem.begin(9600);command(F("ATE0"));initStep=3;return;
   case 3:command(F("AT+CMGF=1"));initStep=4;return;
   default:state=1;Serial.println(F("Modem ready"));return;
  }
 }
 if(state==4){if(due(now,started,20000)){command(F("ATH"));state=5;}return;}
 if(state==5){if(gotOK||gotError||due(now,started,3000))state=1;return;}
 if(state==2){
  if(prompt){
   clearReply();modem.print(F("MO HINH eCO2 - MUC "));modem.print(level);
   modem.print(F(" eCO2="));modem.print(eco2);modem.print(F("ppm T="));
   if(tempValid)modem.print(temp,1);else modem.print(F("LOI"));
   modem.print(F("C. KIEM TRA NGAY!"));modem.write(26);started=now;state=3;
  }else if(gotError||due(now,started,5000)) {modem.write(27);state=1;}
  return;
 }
 if(state==3){
  if(gotOK||gotError||due(now,started,30000)){
   Serial.println(sent?F("SMS accepted"):F("SMS failed/unknown"));state=1;
  }return;
 }
 if(!PHONE[0] || !level)return;
 // At level 3, place call first so a slow SMS cannot postpone the SOS call.
 if(level==3&&(!callEver||due(now,lastCall,60000))){startCall(now);return;}
 if(!smsEver||due(now,lastSMS,60000)){
  lastSMS=now;smsEver=true;clearReply();
  modem.print(F("AT+CMGS=\""));modem.print(PHONE);modem.println('"');started=now;state=2;
 }
}
void setup(){
 pinMode(LED1,OUTPUT);pinMode(LED2,OUTPUT);pinMode(BUZZ,OUTPUT);
 Serial.begin(9600);Wire.begin();Wire.setWireTimeout(25000,true);dht.begin();
 gasOK=gas.begin(0x5A);modem.begin(115200);
 Serial.println(F("DEMO ONLY: eCO2 is NOT measured CO2. Set PHONE in source."));
}
void loop(){uint32_t now=millis();network(now);sample(now);alarms(now);}