Capacitive sensor library problem

Projects Programming
1

This one is really bizarre to my eyes...

If I create a global CapacitiveSensor object the library detects touches just fine.
Bit if I create an object on the stack as a function parameter the library fails completely and returns 0.

WHY?

I can't see anything in the constructor for CapacitiveSensor that would obviously cause this bizarre behavior!

Sketch:

#include <CapacitiveSensor.h>
#include "Manager.h"
#include "Buttons.h"
#include "Debug.h"




CManager Manager;

void setup()
{
  Serial.begin(115200);
  while (!Serial);
  Manager.begin();
  Serial.println(F("Setup complete!"));
}

CapacitiveSensor csButton(A1, A0);

void loop()
{
//CCapacitiveButton cbInc(A1, A0, "INC");
//CapacitiveSensor csButton(A1, A0);

  //cbInc.poll();
  debug.log(csButton.capacitiveSensor(30));
  delay(500);
  //Manager.poll();
}

Constructor:

CapacitiveSensor::CapacitiveSensor(uint8_t sendPin, uint8_t receivePin)
{
	// initialize this instance's variables
	// Serial.begin(9600);		// for debugging
	error = 1;
	loopTimingFactor = 310;		// determined empirically -  a hack

	CS_Timeout_Millis = (2000 * (float)loopTimingFactor * (float)F_CPU) / 16000000;
	CS_AutocaL_Millis = 20000;

	// Serial.print("timwOut =  ");
	// Serial.println(CS_Timeout_Millis);

	// get pin mapping and port for send Pin - from PinMode function in core

#ifdef NUM_DIGITAL_PINS
	if (sendPin >= NUM_DIGITAL_PINS) error = -1;
	if (receivePin >= NUM_DIGITAL_PINS) error = -1;
#endif

	pinMode(sendPin, OUTPUT);						// sendpin to OUTPUT
	pinMode(receivePin, INPUT);						// receivePin to INPUT
	digitalWrite(sendPin, LOW);

	sBit = PIN_TO_BITMASK(sendPin);					// get send pin's ports and bitmask
	sReg = PIN_TO_BASEREG(sendPin);					// get pointer to output register

	rBit = PIN_TO_BITMASK(receivePin);				// get receive pin's ports and bitmask
	rReg = PIN_TO_BASEREG(receivePin);

	// get pin mapping and port for receive Pin - from digital pin functions in Wiring.c
	leastTotal = 0x0FFFFFFFL;   // input large value for autocalibrate begin
	lastCal = millis();         // set millis for start
}
2

WHY?

If you create the object in the loop() context, the object will be created in every run of loop and destroyed when that loop run ends. So the object has no chance to actually see a change in the capacity as it only sees the first value in it's complete lifetime.

3

pylon:
If you create the object in the loop() context, the object will be created in every run of loop and destroyed when that loop run ends. So the object has no chance to actually see a change in the capacity as it only sees the first value in it's complete lifetime.

Well it gets created as a global for the first time and detects a change on the first iteration of a loop.
So I don't get why this can't happen multiple times in a loop context.

At any rate I can't use this library because it is too expensive re memory to use it as intended.

Switched to tactile buttons.