I've just started using the NewPing library with it's 'ping_timer()' and associated functions. It uses Timer2.
I'm wondering which standard operations and library functions I should now avoid so as not to cause conflicts. I think I've read somewhere that some PWM pins use Timer2, but aren't sure which.
I want to use the original Servo and Stepper libraries as well, but I can check the library files to find out which timers they use. Not sure about any others.
Thanks in advance.
OldSteve:
I think I've read somewhere that some PWM pins use Timer2, but aren't sure which.
Depends on the Arduino Board, I think.
Different pins usesd for UNO, LEONARDO, MEGA boards...
On the Uno, it's PWM on pins 3 and 11 that use timer 2.
For other ones, search google image search for the chip name arduino pinout (ie "atmega328p arduino pinout") and look for one that marks the PWM pins with something like OCnX - n is the timer number, X is the channel (A or B). So the pins marked OC2A and OC2B are the ones that use timer2. Not all pinout diagrams list this, though.
(OC stands for Output Compare, which is what the PWM generation is called - it Compares the timer's current value with the value you set, and Outputs the result on the pin)
On a Uno Timer 2 is used for PWM of pin 3 and 11. The servo library uses Timer1 and thus disables the PWM of pin 9 and 10. Timer0 is used by millis and micro.
jurs:
Depends on the Arduino Board, I think.
Different pins usesd for UNO, LEONARDO, MEGA boards...
Oops. Sorry. I should have realised that. I'm referring to the UNO.
And thanks septillion. I'm beginning to get the picture.
Since I'll be using a pair of servos, I can't use PWM on pins 3, 9, 10 or 11.
I'll have to keep in mind that Timer0 is for millis() and micro. I'd better make myself a list I think.
I still haven't checked the 'Stepper' library. I might be in trouble already. If so, I'll use a separate ATtiny (or two) on a small custom board for some things.
DrAzzy:
On the Uno, it's PWM on pins 3 and 11 that use timer 2.For other ones, search google image search for the chip name arduino pinout (ie "atmega328p arduino pinout") and look for one that marks the PWM pins with something like OCnX - n is the timer number, X is the channel (A or B). So the pins marked OC2A and OC2B are the ones that use timer2. Not all pinout diagrams list this, though.
(OC stands for Output Compare, which is what the PWM generation is called - it Compares the timer's current value with the value you set, and Outputs the result on the pin)
Thanks for that. I have a good diagram that does list the OC2a and OC2B, as well as showing equivalent ATMega328P and Arduino pins/ports, that I use for reference. (Attached)
It's handy as a lookup for direct port/pin operations.
Edit: I just checked - the 'Stepper' library uses micros(), so I'm OK there. I'll possibly need either 'SoftwareSerial' or 'SPI', too, so they're next.
