Antenna Listener

Antenna Listener is a library for Arduino and Teensy-like systems. It is able to detect spikes in antenna signals which are send to one of the ADCs of the MCU.
It is published under GNU General Public License 3.0.

Download

Head over to the releases and extract the downloaded folder. Move it to your Arduino IDE Library folder. Restart the IDE. Import it using #import <AntennaListener.h>.

Library

Constructor

AntennaListener(int ap_, int t_, int l_, uint8_t soa_, float _std);

The constructor needs the following arguments:

• int ap_: AntennaPin, the analogPin on which the RF-Signals gets read.
• int t_: Fixed threshold value at which a reading counts as a spike.
• int l_: stdLag, how many samples are backtracked.
• uint8_t: Size of the average & std array. Max 255 values. Normally about 10-25 is a good sample size. Higher value is more stable and therefore "slower" triggering.
• float _std: How big the standard deviation of a value has to be in order to trigger the detection. Depending on the signal values near 0 or as high as multiple deviations are suitable.

void AntennaListener::begin(int buffer[]);

Initial function called in setup. The buffer passed has to be the same size as the uint8_t soa_ in the constructor. Fills the buffer with readings and calculates average and std for the first time.

Functions

count spikes

bool AntennaListener::countSpikes(int overflow);

Counts the values bigger than the threshold over a custom timespan.

• int overflow: Timespan in milliseconds over which all spikes bigger than int t_ are counted. Returns the value.

bool AntennaListener::countSpikes(int overflow, int t_);

• int overflow: Same as above.
• int t_: Custom threshold just for this function.

detect spikes

bool AntennaListener::detectSpike(int buffer[], int stdBuffer[]));

Detects a spike based on the standard deviation. Calculates average and standard deviation on the fly.

• int buffer[]: Buffer in which the readings are stored. Has to be size of uint8_t soa_.
• int stdBuffer[]: Buffer in which the readings for standard deviation are stored (they get converted to a different scale). Has to be size of uint8_t soa_.

bool AntennaListener::detectSpikeByValue(int t_);

Detects a spike based on passing of a threshold.

• int t_: Custom threshold.

measure spikes

void AntennaListener::measureHighestSpike();

Reads the antenna and stores the highest reading in a variable. Can be queried by returnHighestSpike(). Reset by using resetHighestSpike().

reading variables & measurements

uint16_t AntennaListener::readOnlySpikeCounter();

Reads the spike counter but does not reset it.

uint16_t AntennaListener::readSpikeCounter();

Reads the spike counter and clears it.

void AntennaListener::resetSpikeCounter();

Resets the spike counter. Returns nothing.

void AntennaListener::resetHighestSpike();

Resets the highest measured spike.

int AntennaListener::returnAnalogIn();

Returns the analogRead() stored in the last reading-pass.

int AntennaListener::returnAverage();

Returns the latest calculated average from detectSpike().

int AntennaListener::returnHighestSpike();

Returns the value of the highest stored spike. Use resetHighestSpike() to clear.

int AntennaListener::returnLatestReading(int buffer[]));

Returns the latest reading of the value buffer.

uint8_t AntennaListener::returnSizeOfArray();

Returns the size of array used in all buffer[] methods.

int AntennaListener::returnSpikeThreshold();

Returns the value of the spike threshold.

double AntennaListener::returnStd();

Returns the latest calculated standard deviation.

bool AntennaListener::returnTimerFlag();

Returns the timer flag used in countSpikes.