From: Roman Bazalevsky <rvb@rvb.name>
Date: Sat, 1 Oct 2016 08:48:40 +0000 (+0300)
Subject: Сенсор углекислого газа MH-Z14/19 на последовательном интерфейсе.
X-Git-Url: https://git.rvb.name/weathermon.git/commitdiff_plain/41892b7f983c33c2ca0281852d0cddcc2c4df2f1

Сенсор углекислого газа MH-Z14/19 на последовательном интерфейсе.
---

diff --git a/Weather_Station/Weather_Station.ino b/Weather_Station/Weather_Station.ino
index b42f486..3fbdc2e 100644
--- a/Weather_Station/Weather_Station.ino
+++ b/Weather_Station/Weather_Station.ino
@@ -75,15 +75,43 @@ DHT dht;
 #define CO2_PIN A1
 #define DHT_PIN 4
 #define GAS_PIN A0
-#define MHZ14_PIN A2
+// #define MHZ14_PIN A2
 #define START_DELAY 20000
-#define DELAY 50000
+#define DELAY 10000
 
 byte HasBaro;
 
 #define READ_SAMPLE_INTERVAL 50
 #define READ_SAMPLE_TIMES 5
 
+#include <SoftwareSerial.h>;
+
+SoftwareSerial mySerial(8, 9); // 8 - к TX сенсора, 9 - к RX
+
+byte cmd[9] = {0xFF,0x01,0x86,0x00,0x00,0x00,0x00,0x00,0x79}; 
+unsigned char response[9];
+
+int MHZRead()
+{
+  mySerial.write(cmd, 9);
+  memset(response, 0, 9);
+  mySerial.readBytes(response, 9);
+  int i;
+  byte crc = 0;
+  for (i = 1; i < 8; i++) crc+=response[i];
+  crc = 255 - crc;
+  crc++;
+
+  if ( !(response[0] == 0xFF && response[1] == 0x86 && response[8] == crc) ) {
+    return -1;
+  } else {
+    unsigned int responseHigh = (unsigned int) response[2];
+    unsigned int responseLow = (unsigned int) response[3];
+    unsigned int ppm = (256*responseHigh) + responseLow;
+    return ppm;
+  }
+}
+
 float MQRead(int mq_pin)
 {
 
@@ -113,6 +141,7 @@ void setup()
   Serial.println("START");
   Serial1.begin(57600);
   Serial1.println("START");
+  mySerial.begin(9600);
 
   // Initialize the sensor (it is important to get calibration values stored on the device).
 
@@ -216,6 +245,8 @@ void loop()
     }
   }
 
+  delay(DELAY);
+
   delay(dht.getMinimumSamplingPeriod());
 
   DHT_H = dht.getHumidity();
@@ -239,6 +270,8 @@ void loop()
     Serial1.println(dht.getStatusString());
   }
   
+  delay(DELAY);
+  
   Gas = MQRead(GAS_PIN);
   
   Serial.print("SENSOR:TYPE=MQ4,VALUE=");
@@ -246,19 +279,29 @@ void loop()
   Serial1.print("SENSOR:TYPE=MQ4,VALUE=");
   Serial1.println(Gas);
 
+  delay(DELAY);
+
   CO2_raw = MQRead(CO2_PIN);
   Serial.print("SENSOR:TYPE=MQ135,VALUE=");
   Serial.println(CO2_raw);
   Serial1.print("SENSOR:TYPE=MQ135,VALUE=");
   Serial1.println(CO2_raw);
 
-  CO2_MHZ_raw = MQRead(MHZ14_PIN);
-  MHZ_ppm=2000*(CO2_MHZ_raw*5.0/1023)/2.5;
-  Serial.print("SENSOR:TYPE=MHZ14,PPM=");
-  Serial.println(MHZ_ppm);
-  Serial1.print("SENSOR:TYPE=MHZ14,PPM=");
-  Serial1.println(MHZ_ppm);
-  
-  delay(DELAY);  // Pause for 50 seconds.
+  delay(DELAY);
+
+  MHZ_ppm=MHZRead();
+  if (MHZ_ppm<0) {
+    Serial.print("ERROR:TYPE=MHZ14,MESSAGE=CRC Error");
+    Serial.println(MHZ_ppm);
+    Serial1.print("ERROR:TYPE=MHZ14,MESSAGE=CRC Error");
+    Serial1.println(MHZ_ppm);
+  } else {
+    Serial.print("SENSOR:TYPE=MHZ14,PPM=");
+    Serial.println(MHZ_ppm);
+    Serial1.print("SENSOR:TYPE=MHZ14,PPM=");
+    Serial1.println(MHZ_ppm);
+  }
+
+  delay(DELAY);
 }