Arduino Forum

Using Arduino => Microcontrollers => Topic started by: PocketHarambe101 on Oct 19, 2016, 09:16 pm

Title: Overclocking questions?
Post by: PocketHarambe101 on Oct 19, 2016, 09:16 pm
Hi, machine-gun questions incoming!
I read that you can actually overclock the Arduino.
Can anybody tell me how? And does the Arduino get really hot when it is overclocked? I saw some crazy photos of overclocked Arduinos running in liquid nitrogen, apparently for cooling issues.
Also, I bought an Adafruit Metro.https://www.adafruit.com/products/2488 (https://www.adafruit.com/products/2488)
Will be be able to be overclocked too?
Does overclocking harm the board? Will it  shorten its lifespan? Can it explode if I do it wrong(I have exploded a lot of stuff, from LEDs to Arduinos - I'm a newbie)?
Thanks, and sorry for the machine-gun questions!
Title: Re: Overclocking questions?
Post by: DrAzzy on Oct 19, 2016, 09:23 pm
Replace the crystal (or resonator) with a faster one, and use a boards.txt that offers the higher speed. For more aggressive overclocking, you can get it to run a little faster using external clock generator instead of crystal (and setting fuses appropriately for that in your board def, of course)

Heat generation in an atmega328p is minimal, even overclocked. The liquid nitrogen is to get it cold enough that it will run at a higher speed.

any board using an atmega328p as the microcontroller will have similar behavior with regards to overclocking.

Since the '328p doesn't really get hot, overclocking doesn't present the same hazards to the chip as it does in desktop computers.

That said, there's really no point to overclocking an Arduino. There are very few things that won't work at 16mhz but will at say, 24mhz (and you can't really go much higher than that) - usually the CPU requirements of an Arduino project are either really low, or it's something that you can't do with an 8-bit AVR and need to move to some ARM based development board.
Title: Re: Overclocking questions?
Post by: larryd on Oct 19, 2016, 09:27 pm
Quote
I'm a newbie
Recommend you put your efforts into leaning how to program and interface to electronic circuits.
Operate the Arduino chips within the designed limits.

(http://rofl.name/n/?i=noob_kid_knife.jpg)


Title: Re: Overclocking questions?
Post by: Budvar10 on Oct 20, 2016, 08:30 am
I developed a board with the ATmega1284P Arduino clone with 1284P (http://forum.arduino.cc/index.php?topic=277260.0). I have several clock speed versions and also overclocked 24MHz. It runs absolutely reliably. No heating, no harm. Clock speed for ATmega328P, 1284p is up to 20MHz according the datasheet, 16MHz for older ATmegas like 2560. You can find on the internet that ATmega can be overclocked up to 30MHz without the problems. It is not completely true.
My experience is that up to 25MHz it is not a problem, up to now. 25MHz is limit speed to run ADC on max. resolution. So for higher clock speed all functionality is surely not guaranteed.
Of course, you have to modify Arduino SW little bit for better results even it works also without, but nothing horrible.