Can't call function defined as (void)

[kratochviljan]

Any function defined as (void) can not be called by tasker.
Error while compiling:

error: invalid conversion from 'void ()()' to 'TaskCallback {aka void ()(int)}' [-fpermissive]
tasker.setInterval(nrfReceive, 5000)

Tasker.h: 53:6: error: initializing argument 1 of 'bool Tasker::setInterval(TaskCallback, long unsigned int, int, byte)' [-fpermissive]
bool Tasker*: setInterval(TaskCallback func, unsigned long interval, int param, byte prio)
Error compiling project sources

Seems that it is not BUG in Tasker itself, but some restrictions in C/C++

[joysfera]

could you please show me the relevant bits (i.e. the definition of nrfReceive) of your source code?

[kratochviljan]

Yes, surely I can. But it does not matter on mentioned code. Look at two example below, first one not working - error while compiling, second one working fine. The only difference is in the declaration of the called function (void) x (int).

void nrfReceive(void) {
	if (radio.available()) {
		while (radio.available()) {
			radio.read(&meteo, sizeof(meteo));
		}
	}

#ifdef DEBUG
	Serial.println("");
	Serial.print("Velikost packetu: ");
	Serial.print(sizeof(meteo));
	Serial.println("");
	Serial.print("NRF-RX>>>  ");
	Serial.print(meteo.crc);
#endif
}

// NOT WORKING
#include <Tasker.h>
Tasker tasker;

void setup() {
	Serial.begin(115200);
	tasker.setInterval(printsomething, 1000);
}

void loop() {
	tasker.loop();
}

void printsomething(void) {
	Serial.println("Hello Word!");
}

// WORKING FINE

#include <Tasker.h>
Tasker tasker;

void setup() {
	Serial.begin(115200);
	tasker.setInterval(printsomething, 1000);
}

void loop() {
	tasker.loop();
}

void printsomething(int) {
	Serial.println("Hello Word!");
}

[joysfera]

Tasker expects the callback to be defined as void fn(int). The documentation does not explain it explicitly but all examples show that so please define your callbacks with the (int parameter) even if you didn't want to use it. Just like in the MultiBlink example:

void blink1(int /* unused */)
{
...

[kratochviljan]

Yes, I already alter my code that way.

You're definitely a better coder in C/C++ than me, so please correct me if I'm wrong.
Valid declaraction of function i C which has no input arguments and return nothing should be: void function(void) {...}, which is exactly my mentioned case. If I change the declaration to void function (int) {...} copmpiler expect, that function has (int) argument or not ?
(maybe we can continue by mail directly and in Czech I guess...)

[joysfera]

That function will receive an int argument - Tasker is sending that just in case you needed a flag, a counter or something. It does come handy, as the examples show. You are not obliged to use that parameter's value in your function, of course. You can even declare it without a name so it will get ignored. The examples show this as well.

Feel free to mail me directly, I'm going to close this issue.