Is there a way to change the Timers used?

[madacol]

I need to disable and/or change the sequence in which timers are used.

I know how to modify the library to do it, but it's really bothersome to carry a copy of the modified library wherever I go.

I think it's possible to make the Timers opt-out by specifying in the .ino file something like #define doNotUseTimer5 before including the library, and use a #ifndef doNotUseTimer5 to omit lines where Timer5 is defined.

I may do the Pull Request I just described, but I don't know if there already exist something to disable a specific timer, because I see this defined in the source #define _useTimer5 but I don't know how it works or how to use it outside of the library to disable a timer

[Abnaby]

Timers in Arduino UNO:

In Arduino UNO there are three timers used for different functions.
Timer0:
It is an 8-Bit timer and used in timer function such as delay(), millis().
Timer1:
It is a 16-Bit timer and used in servo library.
Timer2:
It is an 8-Bit Timer and used in tone() function.
you can disable all timers by calling noInterrupts();
Parameters None and Returns Nothing
If U need Re-enables interrupts (after they’ve been disabled by nointerrupts())
you can Re-enables it by calling interrupts();
Parameters None Returns Nothing.

if you need to change timer usage or mode,

Timers Mode:

first, I prefer to delete setup and loop and use main() fun.
before start must disable all interrupts by calling noInterrupts();
This register holds the main control bits of the timer and used to control the prescalers of timer. It also allows controlling the mode of timer using the WGM bits.


Prescaler:
The CS12, CS11, CS10 bits in TCCR1B sets the prescaler value. A prescaler is used to setup the clock speed of the timer. Arduino Uno has prescalers of 1, 8, 64, 256, 1024.

Formula for preloader value for the required time in second:
TCNTn = 65535 – (16x1010xTime in sec / Prescaler Value)
To calculate preloader value for timer1 for time of 2 Sec:
TCNT1 = 65535 – (16x1010x2 / 1024) = 34285
small EX
noInterrupts();
Next the Timer1 is initialized.
TCCR1B = 0;
The preloader timer value
TCNT1 = Your_Intial_value;
Then the Pre scaler value 1024 is set in the TCCR1B register.
TCCR1B |= (1 << CS10)|(1 << CS12);

[madacol]

Thank's, it's very informative!

But I'm having a hard time understanding how to use that to stop the Servo library from using a specific timer

[Abnaby]

you need to use another timer or what?

[madacol]

The problem was almost 2 years ago, so I don't remember the specifics.

What I do remember is that the first timer used by this library was interfering with some pins that I needed to use to send a PWM signal.

So I ended up modifying the library, by removing the line #define _useTimer5 (and another thing too that I don't remember now, but it was related and near)

[FernandoGarcia]

Hi!

I think it should be like this:

#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
//#define _useTimer5
#define _useTimer1
#define _useTimer3
#define _useTimer4
//typedef enum { _timer5, _timer1, _timer3, _timer4, _Nbr_16timers } timer16_Sequence_t ;
typedef enum { _timer1, _timer3, _timer4, _Nbr_16timers } timer16_Sequence_t ;

Found here.

Best regards.