-
Notifications
You must be signed in to change notification settings - Fork 27
/
ESP32_bme680_CC_demo_02.ino
154 lines (127 loc) · 6.67 KB
/
ESP32_bme680_CC_demo_02.ino
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
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
/***************************************************************************
This is a library for the BME680 gas, humidity, temperature & pressure sensor
Designed specifically to work with the Adafruit BME680 Breakout
----> http://www.adafruit.com/products/XXXX
These sensors use I2C or SPI to communicate, 2 or 4 pins are required
to interface.
Adafruit invests time and resources providing this open source code,
please support Adafruit andopen-source hardware by purchasing products
from Adafruit!
Written by Limor Fried & Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
***************************************************************************/
#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include "Adafruit_BME680.h"
#define BME_SCK 13
#define BME_MISO 12
#define BME_MOSI 11
#define BME_CS 10
#define SEALEVELPRESSURE_HPA (1013.25)
Adafruit_BME680 bme; // I2C
//Adafruit_BME680 bme(BME_CS); // hardware SPI
//Adafruit_BME680 bme(BME_CS, BME_MOSI, BME_MISO, BME_SCK);
float hum_weighting = 0.25; // so hum effect is 25% of the total air quality score
float gas_weighting = 0.75; // so gas effect is 75% of the total air quality score
float hum_score, gas_score;
float gas_reference = 250000;
float hum_reference = 40;
int getgasreference_count = 0;
void setup() {
Serial.begin(115200);
while (!Serial);
Serial.println(F("BME680 test"));
Wire.begin();
if (!bme.begin()) {
Serial.println("Could not find a valid BME680 sensor, check wiring!");
while (1);
} else Serial.println("Found a sensor");
// Set up oversampling and filter initialization
bme.setTemperatureOversampling(BME680_OS_2X);
bme.setHumidityOversampling(BME680_OS_2X);
bme.setPressureOversampling(BME680_OS_2X);
bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
bme.setGasHeater(320, 150); // 320°C for 150 ms
// Now run the sensor for a burn-in period, then use combination of relative humidity and gas resistance to estimate indoor air quality as a percentage.
GetGasReference();
}
void loop() {
Serial.print("Temperature = ");
Serial.print(bme.readTemperature());
Serial.println("°C");
Serial.print(" Pressure = ");
Serial.print(bme.readPressure() / 100.0F);
Serial.println(" hPa");
Serial.print(" Humidity = ");
Serial.print(bme.readHumidity());
Serial.println("%");
Serial.print(" Gas = ");
Serial.print(bme.readGas());
Serial.println("R\n");
/*
This software, the ideas and concepts is Copyright (c) David Bird 2018. All rights to this software are reserved.
Any redistribution or reproduction of any part or all of the contents in any form is prohibited other than the following:
1. You may print or download to a local hard disk extracts for your personal and non-commercial use only.
2. You may copy the content to individual third parties for their personal use, but only if you acknowledge the author David Bird as the source of the material.
3. You may not, except with my express written permission, distribute or commercially exploit the content.
4. You may not transmit it or store it in any other website or other form of electronic retrieval system for commercial purposes.
The above copyright ('as annotated') notice and this permission notice shall be included in all copies or substantial portions of the Software and where the
software use is visible to an end-user.
THE SOFTWARE IS PROVIDED "AS IS" FOR PRIVATE USE ONLY, IT IS NOT FOR COMMERCIAL USE IN WHOLE OR PART OR CONCEPT. FOR PERSONAL USE IT IS SUPPLIED WITHOUT WARRANTY
OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHOR OR COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
See more at http://www.dsbird.org.uk
*/
//Calculate humidity contribution to IAQ index
float current_humidity = bme.readHumidity();
if (current_humidity >= 38 && current_humidity <= 42)
hum_score = 0.25*100; // Humidity +/-5% around optimum
else
{ //sub-optimal
if (current_humidity < 38)
hum_score = 0.25/hum_reference*current_humidity*100;
else
{
hum_score = ((-0.25/(100-hum_reference)*current_humidity)+0.416666)*100;
}
}
//Calculate gas contribution to IAQ index
float gas_lower_limit = 5000; // Bad air quality limit
float gas_upper_limit = 50000; // Good air quality limit
if (gas_reference > gas_upper_limit) gas_reference = gas_upper_limit;
if (gas_reference < gas_lower_limit) gas_reference = gas_lower_limit;
gas_score = (0.75/(gas_upper_limit-gas_lower_limit)*gas_reference -(gas_lower_limit*(0.75/(gas_upper_limit-gas_lower_limit))))*100;
//Combine results for the final IAQ index value (0-100% where 100% is good quality air)
float air_quality_score = hum_score + gas_score;
Serial.println("Air Quality = "+String(air_quality_score,1)+"% derived from 25% of Humidity reading and 75% of Gas reading - 100% is good quality air");
Serial.println("Humidity element was : "+String(hum_score/100)+" of 0.25");
Serial.println(" Gas element was : "+String(gas_score/100)+" of 0.75");
if (bme.readGas() < 120000) Serial.println("***** Poor air quality *****");
Serial.println();
if ((getgasreference_count++)%10==0) GetGasReference();
Serial.println(CalculateIAQ(air_quality_score));
Serial.println("------------------------------------------------");
delay(2000);
}
void GetGasReference(){
// Now run the sensor for a burn-in period, then use combination of relative humidity and gas resistance to estimate indoor air quality as a percentage.
Serial.println("Getting a new gas reference value");
int readings = 10;
for (int i = 1; i <= readings; i++){ // read gas for 10 x 0.150mS = 1.5secs
gas_reference += bme.readGas();
}
gas_reference = gas_reference / readings;
}
String CalculateIAQ(float score){
String IAQ_text = "Air quality is ";
score = (100-score)*5;
if (score >= 301) IAQ_text += "Hazardous";
else if (score >= 201 && score <= 300 ) IAQ_text += "Very Unhealthy";
else if (score >= 176 && score <= 200 ) IAQ_text += "Unhealthy";
else if (score >= 151 && score <= 175 ) IAQ_text += "Unhealthy for Sensitive Groups";
else if (score >= 51 && score <= 150 ) IAQ_text += "Moderate";
else if (score >= 00 && score <= 50 ) IAQ_text += "Good";
return IAQ_text;
}