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# Grove - Air Quality Sensor v1.3

This sensor is designed for comprehensive monitor over indoor air condition. It's responsive to a wide scope of harmful gases, as carbon monoxide, alcohol, acetone, thinner, formaldehyde and so on. Due to the measuring mechanism, this sensor can't output specific data to describe target gases' concentrations quantitatively. But it's still competent enough to be used in applications that require only qualitative results, like auto refresher sprayers and auto air cycling systems.

## Version¶

Product Version Changes Released Date
Grove - Air Quality Sensor v1.3 Initial May 2016

## Features¶

• Responsive to a wide scope of target gases
• Cost efficient
• Durable
• Compatible with 5V and 3.3V

Cautions

1. Requires relatively clean air as an initial condition.
2. Long time exposure to highly polluted air can significantly weaken its sensitivity.
3. Coffre-fort et armoire forte:

## Platforms Supported¶

Arduino Raspberry Pi BeagleBone Wio LinkIt ONE

Caution

The platforms mentioned above as supported is/are an indication of the module's software or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

## Getting Started¶

Note

If this is the first time you work with Arduino, we firmly recommend you to see Getting Started with Arduino before the start.

### Play With Arduino¶

#### Demonstration¶

As described in Introduction, this sensor performs better in providing qualitative results over a wide scope of target gases. In this demo, we will define 4 statuses for reference in the '.cpp' file. They are:

• a. air fresh -- indicating a good air condition
• b. low pollution -- indicating a rather low concentration of target gases exist.
• c. high pollution(without "Force signal active" message printed on serial monitor) -- you should be aware of the pollution level and consider if some measures could be taken.
• d. high pollution(with "Force signal active" message printed on serial monitor) -- instant measures should be taken to improve the air quality.

We encapsulated the decision structure in a '.cpp' file. You can find information there on how to modify the thresholds.

Let's try it out!

#### Hardware¶

• Step 1. Prepare the below stuffs:
Seeeduino V4.2 Base Shield Grove - Air Quality Sensor
Get One Now Get One Now Get One Now
• Step 2. Connect Grove - Air Quality Sensor to port A0 of Grove-Base Shield.
• Step 3. Plug Grove - Base Shield into Seeeduino.
• Step 4. Connect Seeeduino to PC via a USB cable.

Note

If we don't have Grove Base Shield, We also can directly connect Grove - Air Quality Sensor to Seeeduino as below.

Seeeduino Grove - Air Quality Sensor
5V Red
GND Black
Not Conencted White
A0 Yellow

#### Software¶

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 /* AirQuality Demo V1.0. connect to A1 to start testing. it will needs about 20s to start * By: http://www.seeedstudio.com */ #include"AirQuality.h" #include"Arduino.h" AirQuality airqualitysensor; int current_quality =-1; void setup() { Serial.begin(9600); airqualitysensor.init(A0); } void loop() { current_quality=airqualitysensor.slope(); if (current_quality >= 0)// if a valid data returned. { if (current_quality==0) Serial.println("High pollution! Force signal active"); else if (current_quality==1) Serial.println("High pollution!"); else if (current_quality==2) Serial.println("Low pollution!"); else if (current_quality ==3) Serial.println("Fresh air"); } } ISR(TIMER2_OVF_vect) { if(airqualitysensor.counter==122)//set 2 seconds as a detected duty { airqualitysensor.last_vol=airqualitysensor.first_vol; airqualitysensor.first_vol=analogRead(A0); airqualitysensor.counter=0; airqualitysensor.timer_index=1; PORTB=PORTB^0x20; } else { airqualitysensor.counter++; } } 
• Step 4. We will see the distance display on terminal as below.

To adjust the thresholds and indicating messages, refer to the decision structure below in the .cpp file.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 int AirQuality::slope(void) { while(timer_index) { if(first_vol-last_vol>400||first_vol>700) { Serial.println("High pollution! Force signal active."); timer_index=0; avg_voltage(); return 0; } else if((first_vol-last_vol>400&&first_vol<700)||first_vol-vol_standard>150) { Serial.print("sensor_value:"); Serial.print(first_vol); Serial.println("\t High pollution!"); timer_index=0; avg_voltage(); return 1; } else if((first_vol-last_vol>200&&first_vol<700)||first_vol-vol_standard>50) { //Serial.println(first_vol-last_vol); Serial.print("sensor_value:"); Serial.print(first_vol); Serial.println("\t Low pollution!"); timer_index=0; avg_voltage(); return 2; } else { avg_voltage(); Serial.print("sensor_value:"); Serial.print(first_vol); Serial.println("\t Air fresh"); timer_index=0; return 3; } } return -1; } 

### Play With Raspberry Pi (With Grove Base Hat for Raspberry Pi)¶

#### Hardware¶

• Step 1. Things used in this project:
Raspberry pi Grove Base Hat for RasPi Grove - Air Quality Sensor
Get ONE Now Get ONE Now Get ONE Now
• Step 2. Plug the Grove Base Hat into Raspberry Pi.
• Step 3. Connect the Grove - Air Quality Sensor to the A0 port of the Base Hat.
• Step 4. Connect the Raspberry Pi to PC through USB cable.

#### Software¶

• Step 1. Follow Setting Software to configure the development environment.
• Step 2. Download the source file by cloning the grove.py library.
 1 2 cd ~ git clone https://github.com/Seeed-Studio/grove.py 
• Step 3. Excute below command to run the code.
 1 2 cd grove.py/grove python grove_air_quality_sensor_v1_3.py 0 

Following is the grove_air_quality_sensor_v1_3.py code.

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 import math import sys import time from grove.adc import ADC class GroveAirQualitySensor: def __init__(self, channel): self.channel = channel self.adc = ADC() @property def value(self): return self.adc.read(self.channel) Grove = GroveAirQualitySensor def main(): if len(sys.argv) < 2: print('Usage: {} adc_channel'.format(sys.argv[0])) sys.exit(1) sensor = GroveAirQualitySensor(int(sys.argv[1])) print('Detecting ...') while True: value = sensor.value if value > 100: print("{}, High Pollution.".format(value)) else: print("{}, Air Quality OK.".format(value)) time.sleep(.1) if __name__ == '__main__': main() 

Success

If everything goes well, you will be able to see the following result:

  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 pi@raspberrypi:~/grove.py/grove \$ python grove_air_quality_sensor_v1_3.py 0 Detecting ... 138, High Pollution. 139, High Pollution. 140, High Pollution. 141, High Pollution. 139, High Pollution. 140, High Pollution. 140, High Pollution. 140, High Pollution. 139, High Pollution. 138, High Pollution. 139, High Pollution. 138, High Pollution. 138, High Pollution. ^CTraceback (most recent call last): File "grove_air_quality_sensor_v1_3.py", line 71, in main() File "grove_air_quality_sensor_v1_3.py", line 68, in main time.sleep(.1) KeyboardInterrupt 

You can use this sensor to detect the air quality. Press Ctrl+C to quit.

Notice

You may have noticed that for the analog port, the silkscreen pin number is something like A1, A0, however in the command we use parameter 0 and 1, just the same as the digital port. So please make sure you plug the module into the correct port, otherwise, there may be pin conflicts.

### Play With Raspberry Pi(with GrovePi_Plus)¶

#### Hardware¶

• Step 1. Prepare the below stuffs:
Raspberry pi GrovePi_Plus Grove - Air Quality Sensor
Get One Now Get One Now Get One Now
• Step 2. Plug the GrovePi_Plus into Raspberry.
• Step 3. Connect Grove-MOSFET ranger to A0 port of GrovePi_Plus.
• Step 4. Connect the Raspberry to PC through USB cable.

#### Software¶

• Step 1. Navigate to the demos' directory:
 1 cd yourpath/GrovePi/Software/Python/ 
• Step 2. To see the code
 1 nano grove_air_quality_sensor.py # "Ctrl+x" to exit # 
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 import time import grovepi # Connect the Grove Air Quality Sensor to analog port A0 # SIG,NC,VCC,GND air_sensor = 0 grovepi.pinMode(air_sensor,"INPUT") while True: try: # Get sensor value sensor_value = grovepi.analogRead(air_sensor) if sensor_value > 700: print "High pollution" elif sensor_value > 300: print "Low pollution" else: print "Air fresh" print "sensor_value =", sensor_value time.sleep(.5) except IOError: print "Error" 
• Step 3. Run the demo.
 1 sudo python grove_air_quality_sensor.py 
• Step 4. We will see the output display on terminal as below.

## Projects¶

SPCPM (Solar Powered City Pollution Monitor): Low maintenance, high output air pollution, sound pollution that put throughout the city without wiring.

A website to see the environment data around you:

Home Control Center using BeagleBone Green Wireless:

## Tech Support¶

Please submit any technical issue into our forum.