Vincent19:
I would like to ask do I need to add an external 16MHz crystal or what clock source been configured for the fresh attiny 85 ?
You do not need an external crystal. From the factory, the processor is configured to run at 1 MHz using an internal oscillator. Using the internal oscillator, the processor can be configured to run at 1, 2, 4, 8, or 16 MHz. For all other frequencies you can use an external crystal.
Besides, how can I program it using the arduino IDE ?
Vincent19:
If I use external crystal because I want to use it at 16MHz, then it means I lost 2 IO pins ?
Yes. Two pins are required for an external crystal.
The ATtiny85 is capable of running at 16 MHz using the internal oscillator. You do not need an external crystal for that speed. (The internal oscillator is less accurate and less stable than a crystal. If you need an accurate and/or stable clock then you will have to use a crystal.)
Select the ATtiny85 @ 16 MHz (internal PLL; 4.3 V BOD) board.
Execute Tools / Burn Bootloader.
Enjoy.
By the way, can I confgure the atmega 328 to use internal 16Mhz oscillator too ?
No. As far as I know, the ATtiny85 # is the only AVR processor that can run at 16 MHz using the internal oscillator. The ATmega328 and all other AVR processor can run up to 8 MHz using the internal oscillator.
I thought atmega 328 just can have 1MHz internal
It has an 8 MHz internal oscillator that can be configured to run at 1, 2, 4, or 8 MHz.
* Open the "boards.txt" file and change both of the "upload.using" entries to
** the appropriate value for your setup. Following from the examples above, the**
** file would be here...**
** C:\Projects\Arduino\hardware\tiny\boards.txt**
Start the Arduino IDE and ensure there are two new boards listed under the
[Tools] [Board] menu...
"ATtiny84 @ 8 MHz"
"ATtiny84 @ 1 MHz"
You are now ready to use Arduino-Tiny!
What does the bolded part means ?
I did not do that. And my tools > board now not only contain the 2 new board, but also some others like what you mention(ATtiny85 @ 16 MHz (internal PLL; 4.3 V BOD) board)
Vincent19: * Open the "boards.txt" file and change both of the "upload.using" entries to
** the appropriate value for your setup. Following from the examples above, the**
** file would be here...**
** C:\Projects\Arduino\hardware\tiny\boards.txt**
Start the Arduino IDE and ensure there are two new boards listed under the
[Tools] [Board] menu...
"ATtiny84 @ 8 MHz"
"ATtiny84 @ 1 MHz"
You are now ready to use Arduino-Tiny!
What does the bolded part means ?
I did not do that. And my tools > board now not only contain the 2 new board, but also some others like what you mention(ATtiny85 @ 16 MHz (internal PLL; 4.3 V BOD) board)
I think for the bolded part means I just go and select the board type I need and required ? And delete others ? Hahaha
If I was using an ATtiny85 using the internal oscillator at 8Mhz divided down to 1 Mhz via the prescaler, which option would I use in the IDE:
ATtiny85 @ 8Mhz
or
ATtiny85 @ 1Mhz
Is there any difference in power usage, speed of processing, or anything else material, between running at 8Mhz divided down to 1 Mhz and running at 1Mhz with no prescaler?
lemming:
If I was using an ATtiny85 using the internal oscillator at 8Mhz divided down to 1 Mhz via the prescaler, which option would I use in the IDE:
ATtiny85 @ 1 MHz (internal oscillator; BOD disabled)
lemming:
If I was using an ATtiny85 using the internal oscillator at 8Mhz divided down to 1 Mhz via the prescaler, which option would I use in the IDE:
ATtiny85 @ 1 MHz (internal oscillator; BOD disabled)
So means if 8MHz, delay(1000) will run it as delay 1s? how if 16MHz?