Detailed Description

ID: tp401
Name: TP401 Gas Sensor
Other Names: Grove Air Quality Sensor
Category: gaseous
Manufacturer: seeed
Connection: analog
Link: https://www.seeedstudio.com/Grove-Air-quality-sensor-p-1065.html
Kit: hak

The TP401 Gas Sensor module is useful for monitoring air purity indoors. It can detect CO and a wide range of other harmful gases, but, due to a limited detection range, it should be used only when qualitative results are needed. Example applications are air recirculation, ventilation systems, and refreshing sprayers. The sensor is linear and should be roughly sensitive to 0-20 ppm CO from 0-4 V. Note: the sensor requires 2-3 minutes to warm up initially and 48 hours of operation to stabilize completely.

// Give a qualitative meaning to the value from the sensor
std::string
airQuality(uint16_t value)
{
    if (value < 50)
        return "Fresh Air";
    if (value < 200)
        return "Normal Indoor Air";
    if (value < 400)
        return "Low Pollution";
    if (value < 600)
        return "High Pollution - Action Recommended";
    return "Very High Pollution - Take Action Immediately";
}
int
main()
{
    upm::TP401 airSensor(0);
    cout << airSensor.name() << endl;
    fprintf(stdout, "Heating sensor for 3 minutes...\n");
    // wait 3 minutes for sensor to warm up
    for (int i = 0; i < 3; i++) {
        if (i) {
            fprintf(stdout, "Please wait, %d minute(s) passed..\n", i);
        }
        upm_delay(60);
    }
    fprintf(stdout, "Sensor ready!\n");
    while (true) {
        uint16_t value = airSensor.getSample(); // Read raw value
        float ppm = airSensor.getPPM(); // Read CO ppm (can vary slightly from previous read)
        fprintf(stdout, "raw: %4d ppm: %5.2f   %s\n", value, ppm, airQuality(value).c_str());
        upm_delay_us(2500000); // Sleep for 2.5s
    }
    return 0;
}

Public Member Functions
	TP401 (int gasPin)

	~TP401 ()

std::string	name ()

float	getPPM ()

Public Member Functions inherited from Gas
	Gas (int gasPin)

virtual	~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)