Microphone Class Reference

API for the Analog Microphone. More...

Detailed Description

• ID: microphone
• Name: Analog Microphone
• Other Names: Grove Sound Sensor
• Category: sound
• Manufacturer: seeed
• Link: http://www.seeedstudio.com/wiki/Grove_-_Sound_Sensors
• Connection: pwm
• Kit: gsk

This module defines the Analog Microphone sensor

int
main(int argc, char **argv)
{
    // Attach microphone to analog port A0
    sensor = new upm::Microphone(0);
    signal(SIGINT, sig_handler);

    thresholdContext ctx;
    ctx.averageReading = 0;
    ctx.runningAverage = 0;
    ctx.averagedOver   = 2;

    // Infinite loop, ends when script is cancelled
    // Repeatedly, take a sample every 2 microseconds;
    // find the average of 128 samples; and
    // print a running graph of the averages
    while (!is_running) {
        int len = sensor->getSampledWindow (2, 128, buffer);
        if (len) {
            int thresh = sensor->findThreshold (&ctx, 30, buffer, len);
            sensor->printGraph(&ctx);
            if (thresh) {
                // do something ....
            }
        }
    }

    std::cout << "exiting application" << std::endl;

    delete sensor;

    return 0;
}

Public Member Functions
	Microphone (int micPin)
	~Microphone ()
int	getSampledWindow (unsigned int freqMS, int numberOfSamples, uint16_t *buffer)
int	findThreshold (thresholdContext *ctx, unsigned int threshold, uint16_t *buffer, int len)
void	printGraph (thresholdContext *ctx)

Constructor & Destructor Documentation

Microphone

(

int

micPin

)

Instantiates a Microphone object

Parameters

micPin

Pin where the microphone is connected

~Microphone

(

)

Microphone object destructor

Member Function Documentation

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

Gets samples from the microphone according to the provided window and number of samples

Parameters

freqMS	Time between each sample (in microseconds)
numberOfSamples	Number of sample to sample for this window
buffer	Buffer with sampled data

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

Given the sampled buffer, this method returns TRUE/FALSE if threshold is reached

Parameters

ctx	Threshold context
threshold	Sample threshold
buffer	Buffer with samples
len	Buffer length

void printGraph

(

thresholdContext *

ctx

)

Prints a running average of the threshold context

Parameters

ctx	Threshold context

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The documentation for this class was generated from the following files:

• /iotdk/jenkins/workspace/upm-doc-stable/src/mic/mic.h
• /iotdk/jenkins/workspace/upm-doc-stable/src/mic/mic.cxx