Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: TrickyNekro on October 02, 2007, 12:01:42 AM
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I have heard that AVR are able of overcloaking... without knowing the bad results...
I've heard that ATMEGA8535 can be cloaked to 24MHz!!! And it's thermal response is still good!!!
And. YES, I want to overcloak my AVRs...
Has anyone done this before... I heard of a guy that did...
I guess that you should open the fuse bits, raise the voltage a bit and change the crystal!!! ???
How about PICs???
Warm regards,
Lefteris, Greece
Thanks in advance!!! 8)
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ALL MCU can be overclocked.. but we have the following precautions
1. Overclocking boosts the performance of the MCU by increasing clock frequency, so the power supply should be adequate.
2. though we need a high voltage supply.Do not apply too high voltages beyond the operating level of the MCU, say the operating Voltage of your MCU is from 5-7 V then running it at around 9V is okay but making it at 12V will entirely damage the MCU.
3. Device heat dissipation issue- since we are dealing high voltages we need to have a good and realiable cooling system..
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there is a tutorial for overclocking pics at www.sparkfun.com (http://www.sparkfun.com)
basically they test different crystals andoutput results such as heat, current draw etc..
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if we cool the mcu and give it the higher power supply but not have it fry will it have the same life as one that hasn't been overclocked? if no then roughly by how much can i expect to have the life of the mcu reduce by?
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I can't imagine why you would want to overclock an AVR...
- Jon
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I can't imagine why you would want to overclock an AVR...
- Jon
to boost MCU performance, BEAMers like to do this
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if we cool the mcu and give it the higher power supply but not have it fry will it have the same life as one that hasn't been overclocked?
a BIG, NO.
remember overclocking means going over the manufacturer standards, but my physics professor in college once told me, you will loose 20% of its life when you do overclocking, but this would also depend, say if you are overclocking a cheap and low cost MCU expect it will be damaged a bit faster than those that are in mid-range MCUs
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Well, I understand what it does, but an AVR runs at 20 MIPS - what are you doing that you need more than 20 MIPS?
Perhaps if your application requires that much power, you should consider using something with a little more capability, like an ARM7 (60 MIPS)...
- Jon
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of course, would it be cheaper to do overclocking or buy an ARM7(60 MIPS)?
there are some instances that we are trying to monitor a frequency just a little bit over the highest frequency that the MCU can handle, so my resort do a little tweak, overcloak..
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Guys, thaks a lot for the replies!!!
As we all know some AVR have embeded ADCs and you can also PWM with it... so?!?!
If need a higher sample rate, multitask, heavy processing and many more (multitask? I han't tried it... so not sure about it) overcloaking is ideal
I'm trying to make a biped robot for the next contest with a mounted turrent (ha, probably heatseaker or object seaker (with IR) but I prefer the first one) so I need the movent of several servo simultaniously!!! Or almost simultaniously!!!
I also look for multicore processors so I'll see what I'll do!!!
But I have also started overcloaking... Soon videos and details will come to you!!!
Stay in tought...
Thanks again for the replies...
Top regards, Lefteris
Greece
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Actually, some of the ARM7 chips are cheaper than AVRs...
Go to http://www.newmicros.com, click on TinyARM, and then look at the Tini2131.
- Jon
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Hi,
I can't imagine why you would want to overclock an AVR...
- Jon
to boost MCU performance, BEAMers like to do this
Err ?
I don't see much reason to over clock a microcontroller either, since (natively) faster ones will most likely use less power and be much faster without any undue stress or heat.
Anyway, I'm not really buying the "BEAMers like to do this", since people building BEAM 'bots (which I think you're referring to), since BEAM 'bots don't use microcontrollers at all ;)
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Err ?
Anyway, I'm not really buying the "BEAMers like to do this", since people building BEAM 'bots (which I think you're referring to), since BEAM 'bots don't use microcontrollers at all ;)
i dont want to argue with that, but just surf the web and look for BEAMers all around the world... ;D
Mark Tilden originally defined BEAM without microcontroller, but new born BEAMers now adds microntroller on their BEAM robots, i don't now ... but thanks for the additional information