This is my sketch:
I have a DHT11 sensor, Air quality sensor and a relay with push button actuator running together:
#define MY_DEBUG
#define MY_RADIO_NRF24
#define MY_NODE_ID 10
#include <SPI.h>
#include <MySensors.h>
#include <DHT.h>
#include <Bounce2.h>
#define RELAY_ON 1
#define RELAY_OFF 0
#define RELAY_PIN 3
#define BUTTON_PIN 2
#define HUMIDITY_SENSOR_DIGITAL_PIN 5
#define MQ_SENSOR_ANALOG_PIN (0) //define which analog input channel you are going to use
#define RL_VALUE (1) //define the load resistance on the board, in kilo ohms
#define RO_CLEAN_AIR_FACTOR (9.83) //RO_CLEAR_AIR_FACTOR=(Sensor resistance in clean air)/RO,
#define CALIBARAION_SAMPLE_TIMES (50) //define how many samples you are going to take in the calibration phase
#define CALIBRATION_SAMPLE_INTERVAL (500) //define the time interal(in milisecond) between each samples in the
#define READ_SAMPLE_INTERVAL (50) //define how many samples you are going to take in normal operation
#define READ_SAMPLE_TIMES (5) //define the time interal(in milisecond) between each samples in
#define GAS_LPG (0)
#define GAS_CO (1)
#define GAS_SMOKE (2)
#define CHILD_ID_TEMP 3
#define CHILD_ID_HUM 2
#define CHILD_ID_MQ 0
#define CHILD_ID_SWITCH 1
unsigned long SLEEP_TIME = 6000; // Sleep time between reads (in loops)
unsigned long sleeptimer = 5000;
DHT dht;
float lastTemp;
float lastHum;
bool metric = true;
Bounce debouncer = Bounce();
bool state;
int oldValue = 0;
bool initialValueSent = false;
float Ro = 10000.0; // this has to be tuned 10K Ohm
int val = 0; // variable to store the value coming from the sensor
float valMQ =0.0;
float lastMQ =0.0;
float LPGCurve[3] = {2.3,0.21,-0.47}; //two points are taken from the curve.
float COCurve[3] = {2.3,0.72,-0.34}; //two points are taken from the curve.
float SmokeCurve[3] = {2.3,0.53,-0.44}; //two points are taken from the curve.
MyMessage msg(CHILD_ID_MQ, V_LEVEL);
MyMessage msgPrefix(CHILD_ID_MQ, V_UNIT_PREFIX);
MyMessage msgHum(CHILD_ID_HUM, V_HUM);
MyMessage msgTemp(CHILD_ID_TEMP, V_TEMP);
MyMessage msgSwitch(CHILD_ID_SWITCH, V_LIGHT);
void presentation()
{
sendSketchInfo("Baby", "1.0");
delay(200);
present(CHILD_ID_TEMP, S_TEMP);
delay(200);
present(CHILD_ID_HUM, S_HUM);
delay(200);
present(CHILD_ID_SWITCH, S_LIGHT);
delay(200);
present(CHILD_ID_MQ, S_AIR_QUALITY);
metric = getControllerConfig().isMetric;
}
void setup()
{
pinMode(BUTTON_PIN, INPUT);
digitalWrite(BUTTON_PIN, HIGH);
debouncer.attach(BUTTON_PIN);
debouncer.interval(5);
// Make sure relays are off when starting up
digitalWrite(RELAY_PIN, RELAY_OFF);
pinMode(RELAY_PIN, OUTPUT);
state = loadState(CHILD_ID_SWITCH);
digitalWrite(RELAY_PIN, state?RELAY_ON:RELAY_OFF);
dht.setup(HUMIDITY_SENSOR_DIGITAL_PIN);
sleep(dht.getMinimumSamplingPeriod());
delay(2000);
float temperature = dht.getTemperature();
delay(2000);
float humidity = dht.getHumidity();
delay(100);
send(msgTemp.set(temperature, 1));
delay(100);
send(msgHum.set(humidity, 1));
delay(100);
send(msg.set("0"));
Ro = MQCalibration(
MQ_SENSOR_ANALOG_PIN); //Calibrating the sensor. Please make sure the sensor is in clean air
send(msgPrefix.set("gas"));
}
void loop() {
if (!initialValueSent) {
Serial.println("Sending initial value");
send(msgSwitch.set(state?RELAY_ON:RELAY_OFF));
Serial.println("Requesting initial value from controller");
request(CHILD_ID_SWITCH, V_STATUS);
wait(2000, C_SET, V_STATUS);
}
debouncer.update();
int value = debouncer.read();
if (value != oldValue && value==0) {
send(msgSwitch.set(state?false:true), true); // Send new state and request ack back
}
oldValue = value;
if (sleeptimer > SLEEP_TIME) {
sleeptimer= 0;
// Fetch temperatures from DHT sensor
float temperature = dht.getTemperature();
if (isnan(temperature)) {
Serial.println("Failed reading temperature from DHT");
} else if (temperature != lastTemp) {
lastTemp = temperature;
if (!metric) {
temperature = dht.toFahrenheit(temperature);
}
send(msgTemp.set(temperature, 1));
#ifdef MY_DEBUG
Serial.print("T: ");
Serial.println(temperature);
#endif
}
// Fetch humidity from DHT sensor
float humidity = dht.getHumidity();
if (isnan(humidity)) {
Serial.println("Failed reading humidity from DHT");
} else if (humidity != lastHum) {
lastHum = humidity;
send(msgHum.set(humidity, 1));
#ifdef MY_DEBUG
Serial.print("H: ");
Serial.println(humidity);
#endif
}
// Qualidade do Ar
uint16_t valMQ = MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_CO) + MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_LPG) + MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_SMOKE);
Serial.print("LPG:");
Serial.print(MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_LPG));
Serial.print( "ppm" );
Serial.print(" ");
Serial.print("CO:");
Serial.print(MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_CO));
Serial.print( "ppm" );
Serial.print(" ");
Serial.print("SMOKE:");
Serial.print(MQGetGasPercentage(MQRead(MQ_SENSOR_ANALOG_PIN)/Ro,GAS_SMOKE));
Serial.print( "ppm" );
Serial.print("\n");
if (valMQ != lastMQ) {
send(msg.set((int16_t)ceil(valMQ)-20));
lastMQ = ceil(valMQ);
}
} else sleeptimer++;
delay(10);
}
void receive(const MyMessage &message) {
if (message.isAck()) {
Serial.println("This is an ack from gateway");
}
if (message.type == V_LIGHT) {
if (!initialValueSent) {
Serial.println("Receiving initial value from controller");
initialValueSent = true;
}
// Change relay state
state = message.getBool();
digitalWrite(RELAY_PIN, state?RELAY_ON:RELAY_OFF);
saveState(CHILD_ID_SWITCH, state);
send(msgSwitch.set(state?RELAY_ON:RELAY_OFF));
}
}
/****************** MQResistanceCalculation ****************************************
Input: raw_adc - raw value read from adc, which represents the voltage
Output: the calculated sensor resistance
Remarks: The sensor and the load resistor forms a voltage divider. Given the voltage
across the load resistor and its resistance, the resistance of the sensor
could be derived.
************************************************************************************/
float MQResistanceCalculation(int raw_adc)
{
return ( ((float)RL_VALUE*(1023-raw_adc)/raw_adc));
}
/***************************** MQCalibration ****************************************
Input: mq_pin - analog channel
Output: Ro of the sensor
Remarks: This function assumes that the sensor is in clean air. It use
MQResistanceCalculation to calculates the sensor resistance in clean air
and then divides it with RO_CLEAN_AIR_FACTOR. RO_CLEAN_AIR_FACTOR is about
10, which differs slightly between different sensors.
************************************************************************************/
float MQCalibration(int mq_pin)
{
int i;
float val=0;
for (i=0; i<CALIBARAION_SAMPLE_TIMES; i++) { //take multiple samples
val += MQResistanceCalculation(analogRead(mq_pin));
delay(CALIBRATION_SAMPLE_INTERVAL);
}
val = val/CALIBARAION_SAMPLE_TIMES; //calculate the average value
val = val/RO_CLEAN_AIR_FACTOR; //divided by RO_CLEAN_AIR_FACTOR yields the Ro
//according to the chart in the datasheet
return val;
}
/***************************** MQRead *********************************************
Input: mq_pin - analog channel
Output: Rs of the sensor
Remarks: This function use MQResistanceCalculation to caculate the sensor resistenc (Rs).
The Rs changes as the sensor is in the different consentration of the target
gas. The sample times and the time interval between samples could be configured
by changing the definition of the macros.
************************************************************************************/
float MQRead(int mq_pin)
{
int i;
float rs=0;
for (i=0; i<READ_SAMPLE_TIMES; i++) {
rs += MQResistanceCalculation(analogRead(mq_pin));
delay(READ_SAMPLE_INTERVAL);
}
rs = rs/READ_SAMPLE_TIMES;
return rs;
}
/***************************** MQGetGasPercentage **********************************
Input: rs_ro_ratio - Rs divided by Ro
gas_id - target gas type
Output: ppm of the target gas
Remarks: This function passes different curves to the MQGetPercentage function which
calculates the ppm (parts per million) of the target gas.
************************************************************************************/
int MQGetGasPercentage(float rs_ro_ratio, int gas_id)
{
if ( gas_id == GAS_LPG ) {
return MQGetPercentage(rs_ro_ratio,LPGCurve);
} else if ( gas_id == GAS_CO ) {
return MQGetPercentage(rs_ro_ratio,COCurve);
} else if ( gas_id == GAS_SMOKE ) {
return MQGetPercentage(rs_ro_ratio,SmokeCurve);
}
return 0;
}
/***************************** MQGetPercentage **********************************
Input: rs_ro_ratio - Rs divided by Ro
pcurve - pointer to the curve of the target gas
Output: ppm of the target gas
Remarks: By using the slope and a point of the line. The x(logarithmic value of ppm)
of the line could be derived if y(rs_ro_ratio) is provided. As it is a
logarithmic coordinate, power of 10 is used to convert the result to non-logarithmic
value.
************************************************************************************/
int MQGetPercentage(float rs_ro_ratio, float *pcurve)
{
return (pow(10,( ((log10(rs_ro_ratio)-pcurve[1])/pcurve[2]) + pcurve[0])));
}