const int co2_warning_thr = 1000;
const int co2_alarm_thr = 1500;
+const unsigned long warmuptime = 60000; // 1 min.
+
MHZ19 mhz19 = MHZ19(rx_pin,tx_pin);
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
unsigned long time;
-unsigned long warmuptime = 60000; // 1 min.
int co2 = 0;
int temp = 0;
int lastppm = 0;