Overclocking microcontrollers

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copterrichie
Posts: 2261
Joined: Sat Feb 19, 2011 8:30 pm

Overclocking microcontrollers

Post by copterrichie »

Maybe there is still a good usage for the ATMega328

We’re all familiar with overclocking desktop computers; a wonderful introduction to thermal design power and the necessities of a good CPU cooler. [Marcelo] wanted to see how far he could overclock a microcontroller – in this case an ATMega328 – and ended up with a microcontroller designed for 20 MHz running at 30 MHz.

To verify that his uC could run at higher clock speeds, [Marcelo] began his experiments by uploading a piece of code that toggled a few pins as fast as possible. He needed to upload this code with a common 16 MHz crystal – AVRDude simply won’t work when a chip is clocked at higher speeds.

After successfully demonstrating his microcontroller will turn pins on and off at 30 MHz, [Marcelo] wanted to see if he could do something useful. By editing a single setting in his Arduino boards.txt file., [Marcelo] was able to have his overclocked microcontroller read and reply to characters sent over a serial connection. It worked, demonstrating an overclocked microcontroller could be useful in some situations.

As for what [Marcelo] plans to do with his faster microcontroller, he’s thinking of improving a ATMega-powered VGA color generator. A higher clock speed means he can push more pixels out to a VGA monitor.


http://hackaday.com/2012/12/27/overcloc ... ntrollers/

QuadBow
Posts: 532
Joined: Fri Jan 04, 2013 10:06 am

Re: Overclocking microcontrollers

Post by QuadBow »

Well, overclocking on the laboratory is nice experiment, doing so at a height of few hundred feet another topic.
Have all the hardware devices (serial, i2c, interrupts, eeprom access, etc) been tested in parallel under all circumstances?
I doubt that experiments like flipping one single led are proof enough to come to the conclusion that the atmega328 works at 30 Mhz.
In particular the access to the eeprom has been reported back many times as an issue occurring already at slightly (20%) overclocking frequencies.
And the multiwii eeprom is the storage for important parameters for instance pid values...

If there is any need for higher speed I recommend
either to use a second board eg. for gps via i2c
or to go an ARM based solution instead of exceeding atmel's specifications.

tovrin
Posts: 705
Joined: Tue Sep 20, 2011 4:08 pm

Re: Overclocking microcontrollers

Post by tovrin »

I thought the reason for the need for a newer controller wasnt the clock speed but the peripherals, we are running out of connections on the arduino. am i wrong?

copterrichie
Posts: 2261
Joined: Sat Feb 19, 2011 8:30 pm

Re: Overclocking microcontrollers

Post by copterrichie »

With a faster clock speed, just means a shorter loop time. This was just a FYI post not meant to be used for flight systems. Would be interesting for an OSD system because it would update the screens faster.

Parham26
Posts: 1
Joined: Thu Jul 28, 2022 2:13 pm

Re: Overclocking microcontrollers

Post by Parham26 »

Hello. Do you have any articles or brochures about overclocking microcontrollers? Thank you.
avr and arm

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