Sensor - K30 - CO2 meting

Hardware

De K30 is een CO2 sensor die kan worden gebruikt voor diverse meet- en controle toepassingen. Dit platform is ontworpen als OEM module om ingebouwd te worden in bestaande apparaten. De K30 is een sensor met 2 analoge en 2 digitale Output signalen.

Informatie (ENG)

Measurement range CO₂	0 to 5000 ppm / 0 to 3%vol
Accuracy	±30 ppm ±3% of reading
Dimensions	57 mm x 51 mm x 14 mm
Operation temperature range	0 to 50 °C
Power supply	4.5 to 14.0 V DC
Communication	Uart ( Modbus)
Outputs
OUT ₁ linear output	0 to 4 V DC = 0 to 2000 ppm
OUT₂ linear output	1 to 5 V DC = 0 to 2000 ppm
OUT ₃ digital output	700/800 ppm
OUT ₄ digital output	900/1000 ppm

Why the K-30?

The K-30 is an non-dispersive infrared (NDIR) CO2 sensor. Unlike electrochemical CO2 sensors, NDIR sensors use light to measure the wavelength of CO2 molecules. Electrochemical sensors last a few years. With normal care, the K-30 will last upwards of 15 years.
NDIR sensors tend to be more accurate and have a faster response rate than electrochemical sensors.
The K-30 is easy to talk to. It uses an industry-standard UART TXD-RXD connection.

All this having been said, electrochemical sensors are cheaper. If you only want to know if CO2 levels are high/medium/low, a low-cost electrochemical sensor is a reasonable alternative. But if you want to accurately measure CO2 levels in parts-per-million over time, the K-30 is a great sensor.

Pinout

Deze sensor heeft o.a. een UART (TX/RX) en I2C (SCA/SDA) digitale interface:

Arduino

Aansluiten op de Arduino (Analoog)

Het is ook mogelijk de K30 sensor uit te lezen via een analoge uitgang, deze bied een 5mv resolutie tot 2000 PPM.

Sluit de K30 module aan op de Arduino volgens onderstaand overzicht:

K30 pin:	Arduino pin:	Voeding:
OUT 2	A0
4 - GND	GND	GND
5 - VCC (3v - 6v)		VCC (3v - 6v)

Script Analoog

Onderstaand script geeft het aantal PPM weer van de CO2 in de lucht (tot max. 2000 ppm).

int analogPin = 0;

int val = 0;
int volt;
int waarde;

void setup() {
  Serial.begin(9600);
}

void loop() {
  volt = analogRead(analogPin);
  waarde = map(volt, 0, 1023, 0, 2000);
  Serial.print("PPM Waarde: ");
  Serial.println(waarde);
  delay(1000);
}

int analogPin = 0;

int val = 0;

int volt;

int waarde;

void setup() {

Serial.begin(9600);

}

void loop() {

volt = analogRead(analogPin);

waarde = map(volt, 0, 1023, 0, 2000);

Serial.print("PPM Waarde: ");

Serial.println(waarde);

delay(1000);

}

Het resultaat

PPM Waarde: 515
PPM Waarde: 511
PPM Waarde: 511
PPM Waarde: 511
PPM Waarde: 505
PPM Waarde: 511

PPM Waarde: 515

PPM Waarde: 511

PPM Waarde: 505

PPM Waarde: 511

Aansluiten op de Arduino (I2C)

Pinout:

Sluit de K30 module aan op de Arduino volgens onderstaand overzicht:

K30 pin:	Arduino pin:	Voeding:
2 - SDA (Serial Data)	A4
3 - SDL (Serial Clock)	A5
4 - GND	GND	GND
5 - VCC (3v - 6v)		VCC (3v - 6v)

Script I2C

Wat heb je nodig?

– Arduino K30 Co2 sensor bibliotheek

Onderstaand script geeft het aantal PPM weer van de CO2 in de lucht.

#include <K30_I2C.h>

void setup() {
  Serial.begin(9600);
}

K30_I2C k30_i2c = K30_I2C(0x68);

int co2 = 0;
int rc  = 1;

void loop() {
  Serial.print("Reading K30 sensor ...... \n");
  rc = k30_i2c.readCO2(co2);
  if (rc == 0){
    Serial.print("Succesful reading\n");
    Serial.print(co2);
    Serial.print(" ppm");
  } else{
    Serial.print("Failure to read sensor\n");  
  }
  Serial.println("\n"); 
  delay(3000); //time between readings
}

#include <K30_I2C.h>

void setup() {

Serial.begin(9600);

}

K30_I2C k30_i2c = K30_I2C(0x68);

int co2 = 0;

int rc = 1;

void loop() {

Serial.print("Reading K30 sensor ...... \n");

rc = k30_i2c.readCO2(co2);

if (rc == 0){

Serial.print("Succesful reading\n");

Serial.print(co2);

Serial.print(" ppm");

} else{

Serial.print("Failure to read sensor\n");

}

Serial.println("\n");

delay(3000); //time between readings

}

Het resultaat

Reading K30 sensor ...... 
Succesful reading
573 ppm

Reading K30 sensor ...... 
Succesful reading
573 ppm

Reading K30 sensor ...... 
Succesful reading
574 ppm

Reading K30 sensor ...... 
Succesful reading
577 ppm

Reading K30 sensor ...... 
Succesful reading
578 ppm

Reading K30 sensor ......

Succesful reading

573 ppm

Reading K30 sensor ......

Succesful reading

573 ppm

Reading K30 sensor ......

Succesful reading

574 ppm

Reading K30 sensor ......

Succesful reading

577 ppm

Reading K30 sensor ......

Succesful reading

578 ppm

Bronnen:
create.arduino.cc

Aansluiten op de Arduino (UART)

Het is ook mogelijk de K30 sensor uit te lezen via RX/TX , echter krijg ik hem niet aan de praat, ook niet op een Arduino MEGA op serial1/2 en verschillende baud rates geprobeerd!

Sluit de K30 module aan op de Arduino volgens onderstaand overzicht:

K30 pin:	Arduino pin:	Voeding:
RX	13 (TX)
TX	12 (RX)
4 - GND	GND	GND
5 - VCC (3v - 6v)		VCC (3v - 6v)

Script UART

Onderstaand script geeft het aantal PPM weer van de CO2 in de lucht.

// AN-126 Demo of K-30 using Software Serial
#include <SoftwareSerial.h>
/*
 Basic Arduino example for K-Series sensor
 Created by Jason Berger
 Co2meter.com
*/
#include "SoftwareSerial.h"
SoftwareSerial K_30_Serial(12, 13); //Sets up a virtual serial port, using pin 12 for Rx and pin 13 for Tx
byte readCO2[] = {0xFE, 0X44, 0X00, 0X08, 0X02, 0X9F, 0X25}; //Command packet to read Co2 (see app note)
byte response[] = {0,0,0,0,0,0,0}; //create an array to store the response
//multiplier for value. default is 3. set to 3 for K-30 and 10 for K-33 ICB
int valMultiplier = 3;

void setup() {
  Serial.begin(9600); //Opens the main serial port to communicate with the computer
  K_30_Serial.begin(9600); //Opens the virtual serial port with a baud of 9600
  Serial.println("Demo of AN-126 Software Serial and K-40 Sensor");
}

void loop() {
  sendRequest(readCO2);
  unsigned long valCO2 = getValue(response);
  Serial.print("Co2 ppm = ");
  Serial.println(valCO2);
  delay(2000);
}

void sendRequest(byte packet[]) {
  while(!K_30_Serial.available()) { //keep sending request until we start to get a response
    Serial.println("waiting for Software.serial port availability");
    K_30_Serial.write(readCO2,7);
    delay(50); 
  }
  int timeout=0; //set a timeout counter
  while(K_30_Serial.available() < 7 ) {//Wait to get a 7 byte response
    timeout++;
    if(timeout > 10) { //if it takes too long there was probably an error
       while(K_30_Serial.available()) //flush whatever we have
       K_30_Serial.read();
       break; //exit and try again
    }
  delay(50);
  }
  for (int i=0; i < 7; i++) { response[i] = K_30_Serial.read(); }
}

unsigned long getValue(byte packet[]) {
  int high = packet[3]; //high byte for value is 4th byte in packet in the packet
  int low = packet[4]; //low byte for value is 5th byte in the packet
  unsigned long val = high*256 + low; //Combine high byte and low byte with this formula to get value
  return val* valMultiplier;
}

// AN-126 Demo of K-30 using Software Serial

#include <SoftwareSerial.h>

Basic Arduino example for K-Series sensor

Created by Jason Berger

Co2meter.com

#include "SoftwareSerial.h"

SoftwareSerial K_30_Serial(12, 13); //Sets up a virtual serial port, using pin 12 for Rx and pin 13 for Tx

byte readCO2[] = {0xFE, 0X44, 0X00, 0X08, 0X02, 0X9F, 0X25}; //Command packet to read Co2 (see app note)

byte response[] = {0,0,0,0,0,0,0}; //create an array to store the response

//multiplier for value. default is 3. set to 3 for K-30 and 10 for K-33 ICB

int valMultiplier = 3;

void setup() {

Serial.begin(9600); //Opens the main serial port to communicate with the computer

K_30_Serial.begin(9600); //Opens the virtual serial port with a baud of 9600

Serial.println("Demo of AN-126 Software Serial and K-40 Sensor");

}

void loop() {

sendRequest(readCO2);

unsigned long valCO2 = getValue(response);

Serial.print("Co2 ppm = ");

Serial.println(valCO2);

delay(2000);

}

void sendRequest(byte packet[]) {

while(!K_30_Serial.available()) { //keep sending request until we start to get a response

Serial.println("waiting for Software.serial port availability");

K_30_Serial.write(readCO2,7);

delay(50);

}

int timeout=0; //set a timeout counter

while(K_30_Serial.available() < 7 ) {//Wait to get a 7 byte response

timeout++;

if(timeout > 10) { //if it takes too long there was probably an error

while(K_30_Serial.available()) //flush whatever we have

K_30_Serial.read();

break; //exit and try again

}

delay(50);

}

for (int i=0; i < 7; i++) { response[i] = K_30_Serial.read(); }

}

unsigned long getValue(byte packet[]) {

int high = packet[3]; //high byte for value is 4th byte in packet in the packet

int low = packet[4]; //low byte for value is 5th byte in the packet

unsigned long val = high*256 + low; //Combine high byte and low byte with this formula to get value

return val* valMultiplier;

}

Bronnen:
instructables.com
community.particle.io

Arduino Library

K30 CO2 sensor module I2C Library

This is an Arduino Library for K30 CO2 NDIR module from Senseair. The sensor module is connected to Arduino using I2C. The sensor module is powered by an external power supply (5V or higher) capable of 1000mA.

The library contains two example sketches for two configurations: