API for the MQ9 Gas Sensor. More...

Detailed Description

ID: mq9
Name: Grove MQ9 Gas Sensor
Category: gaseous
Manufacturer: seeed
Connection: analog

The Grove MQ9 Gas Sensor module is useful for gas leakage detection (in home and industry). It can detect carbon monoxide, coal gas, and liquefied gas. Its sensitivity is 10-1,000 ppm CO, and 100-10,000 ppm Gas.

int
main(int argc, char **argv)
{
    sensor = new upm::MQ9(0);
    signal(SIGINT, sig_handler);
    thresholdContext ctx;
    ctx.averageReading = 0;
    ctx.runningAverage = 0;
    ctx.averagedOver   = 2;
    while (!is_running) {
        int len = sensor->getSampledWindow (2, 128, buffer);
        if (len) {
            int thresh = sensor->findThreshold (&ctx, 30, buffer, len);
            sensor->printGraph(&ctx, 5);
            if (thresh) {
                // do something ....
            }
        }
    }
    std::cout << "exiting application" << std::endl;
    delete sensor;
    return 0;
}

Public Member Functions
	MQ9 (int gasPin)

	~MQ9 ()

std::string	name ()

Public Member Functions inherited from Gas
	Gas (int gasPin)

	~Gas ()

virtual int	getSampledWindow (unsigned int freqMS, int numberOfSamples, uint16_t *buffer)

virtual int	findThreshold (thresholdContext ctx, unsigned int threshold, uint16_t buffer, int len)

virtual int	getSampledData (thresholdContext *ctx)

virtual int	getSample ()

virtual void	printGraph (thresholdContext *ctx, uint8_t resolution)