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Topic: External 32 KHz timer2 in order to shutdown (Read 1 time) previous topic - next topic

Nick Gammon


GoForSmoke

This makes me think about the vast number of projects where AVR is a bit overkill.

I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

denisj

Thanks a lot all of you guys ... it's wonderfool to see a lot of help.

I just ordered yesterday some 32,768 MHz crystals in order
to begin to test it.

So after i read (but not understand all) the wonderfool article post by Nick (http://www.gammon.com.au/power)
i understand this steps:

- i must run it using the Timer2 trained by an 32MHz external quartz in order to have an accurate time after wake up
- i must program the atmel in order to use 8MHz (i anyway need at last 4Mhz in order to use the RFM12B for rf transmitter)
- for the LED pulse i will use the LOW interrupt wake-up on pin 5 of atmel
  (i hope will fill the LOW status, cause now in my program i use the RISING status)

Is everything right until now ?
The Timer2 is work in "Power Down" mode ? ..or it's work only in "Power Save" mode ?

I just must understand about how to program the atmel in this case.
If I understand I can not use the normal flash using the bootloader
cause of use of internal 8MHz RC clock... it is there a bootloader that can use 8MHz internal clock ?

Thanks a lot again
Denis

Nick Gammon

Quote
cause of use of internal 8MHz RC clock... it is there a bootloader that can use 8MHz internal clock ?


Yes there are 8 MHz bootloaders. The Lilypad is one I think.

GoForSmoke

There's Arduino as ISP to minimal config breadboard 8 Mz.
http://arduino.cc/en/Tutorial/ArduinoToBreadboard

AFAICT this warning applies to UNO's with 168 chips, not 328's, see the chip-specific part in parenthesis. I can tell as far as my 328-chip UNO bootloading and programming 328P-PU's
using material and wiring from that link.

Quote
Note that these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168).


Hard to predict change, that comment must be ooooooooooooooold!
I find it harder to express logic in English than in Code.
Sometimes an example says more than many times as many words.

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