Class AnalogDistanceSensor

Inheritance Relationships

Base Type

Derived Type

Class Documentation

class AnalogDistanceSensor : public tap::sensors::DistanceSensor

Basic analog IR Sensor.

  • The distance conversion can be tweaked depending on the sensor.

  • Min and max distance are in cm.

See here (https://i.stack.imgur.com/babQg.png) for a graph of what an IR sensor should look like. Datasheets will have specifics for what the distance curve should look like. Thsi class gives a general curve fit that first calculates a linear fit from the raw voltage of the form \( y=mx+b \) and then the output is put into the equation \( dist = \frac{1}{linear} + offset \).

Subclassed by tap::sensors::SharpIrGP2Y0A41

Public Functions

AnalogDistanceSensor(Drivers *drivers, float minDistance, float maxDistance, float m, float b, float offset, gpio::Analog::Pin pin)

Constructor to initialize the analog IR boundary, distance conversion, and analog pin.

Parameters:

  • minDistance – [in] the sensor’s min valid distance

  • maxDistance – [in] the sensor’s max valid distance

  • m – [in] the slope of the linear model that describes the relationship between analog input and distance.

  • b – [in] the y intercept of the linear model that describes the relationship between analog input and distance.

  • offset – [in] the offset in the non-linear portion of the model.

  • pin – [in] the analog pin that the sensor is connected to.

virtual float read() override

Reads the sensor, updates the current distance, and returns this reading.

Returns:

the updated value. May or may not be valid. If it is not valid, -1 is returned.

virtual bool validReading() const override

Checks if current reading is within bounds.

Returns:

true if the reading is within the min and max distance, exclusive. Returns false otherwise.