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Topic: INTx, documentation vs schem vs chip (Read 742 times) previous topic - next topic

Graynomad

Feb 07, 2011, 08:48 am Last Edit: Feb 07, 2011, 08:50 am by Graynomad Reason: 1
Didn't we used to have a documentation section?

Anyway I'm looking at the Mega schematics and documentation and can't seem to match the two, for example interrupt 0 is on DIG2 according to the docs but digital 2 goes to INT4 on the chip, the others are different as well, as follows

2 (interrupt 0)      INT4, pin 6 on chip
3 (interrupt 1)      INT5, pin 7
21 (interrupt 2)    INT0, pin 43
20 (interrupt 3)    INT1, pin 44
19 (interrupt 4)    INT2, pin 45
18 (interrupt 5)    INT3, pin 46

So is something wrong or are the Arduino "interrupts" just logical numbers that map to a different real interrupt?

Also digital 0 and 1 (Rx0 and Tx0) are shown as PWM on the schematic, presumably this just means that you can do a digitalWrite() as there's no hardware PWM support on these pins.
______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

RuggedCircuits

Quote
are the Arduino "interrupts" just logical numbers that map to a different real interrupt?


Bingo.

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Also digital 0 and 1 (Rx0 and Tx0) are shown as PWM on the schematic, presumably this just means that you can do a digitalWrite() as there's no hardware PWM support on these pins.


I think this is a schematic labelling error. Those pins (PE0 and PE1) are not connected to timers thus do not support PWM.

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