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Hey,

Will someone be so kind and upload the blink sketch, let it run for let us say 5 minutes and then feel if the sam3x8e gets warm/hot.. I'm asking this because I recently made a due clone... After uploading the blink sketch, for some odd reason I felt the sam3x8e chip, and it was kinda warm.. I did the same thing on my (original) due with the same result.. Is it something normal for the chip to get warm?? Is it like the new smartphones where it gets warm on the back (HTC One X =P) where the processor is??

Edit: Both boards were running with power from the native usb port..
« Last Edit: March 11, 2013, 02:14:41 pm by baselsw » Logged

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Well, which LEDs do you use? LED 13? While the Arduino uses an Amplifier, your board directly (?) connects to the LED. But in both ways, the Chip can only provide 3 to 15mA. I dont know if the LED on the Due Board is an Low Current LED but otherwise it would need a higher current than the DUE can provide and maybe even damage the Chip.

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Well, which LEDs do you use? LED 13? While the Arduino uses an Amplifier, your board directly (?) connects to the LED. But in both ways, the Chip can only provide 3 to 15mA. I dont know if the LED on the Due Board is an Low Current LED but otherwise it would need a higher current than the DUE can provide and maybe even damage the Chip.



Well I took the blink sketch as an example.. Just a sketch to get the processor going (to do something not to intense). Try uploading an empty sketch with maybe only a delay in it. something like:

Code:
void setup() {
}
void loop() {
 delay(1);
}


And let it run for 5 minutes..

It's not like it gets hot.. Just a bit warm, something I never experienced with a AVR (maybe because of the freq. that the processor is working with).. That's why I'm asking anyone here to try uploading something simple and let it run for 5 minutes.. It's not critical, just something I found out on my way.. Just to point it out again, this happens on the original arduino due aswell..


Edit: It's nothing critical nor something electrically wrong... By hard-erasing the chip it gets cold again... So the warmth is just the processor doing some work...
« Last Edit: March 11, 2013, 04:12:00 pm by baselsw » Logged

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I couldn't let this to rest.. I just had to prove that nothing is wrong with the chip.. So I programmed the chip to read of the internal temperature sensor (sensitivity of (+/-)1ºC) and throw out the temperature through serial.. Here is the a plot of the temperature as a function of time (since power on). Hope this is useful for someone as curious as me =).. I've also included the .bin file for anyone who want to try this out (no sketch because this is written in atmel studio).. Upload the .bin file using bossac with the following line (Native port).

Code:
bossac.exe --port=COM18 -U true -e -w -v -b ADC_TEMP_SENSOR.bin -R


* image001.png (28.26 KB, 1334x786 - viewed 70 times.)
* ADC_TEMP_SENSOR.bin (23.56 KB - downloaded 17 times.)
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It's not like it gets hot.. Just a bit warm, something I never experienced with a AVR (maybe because of the freq. that the processor is working with)..

Exactly that, the logic gates consume power when they change state, if you are running at a higher frequency then the chip consumes more power (all other things being equal). 28 degrees is well within normal. Nice work with the temperature chart btw  smiley

Given the fact that you have many more gates in an ARM compared to an AVR and are clocking them 4 times faster, it is pretty good that it does not get hotter. Running at lower voltage (3.3V vs 5V) helps a lot with that, as well as the CPU design. By comparison, the old 486 from Intel needed at least a heatsink to run at similar clock rates, if not active cooling.
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Hi Basel,

Just dug up this old thread - I've just burned your temp sensor code to my Due board with BOSSAC, and after about 5 minutes the chip is at ~36.4degrees, and it can't be more than 20 degrees inside here today!

What was ambient when you did the test?
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Hi Basel,

Just dug up this old thread - I've just burned your temp sensor code to my Due board with BOSSAC, and after about 5 minutes the chip is at ~36.4degrees, and it can't be more than 20 degrees inside here today!

What was ambient when you did the test?

Hey,

Well, can't exactly remember.. But not more than 15-17ºC... 36.4ºC is kinda normal.. The internal temp. sensor isn't that accurate either.. And I don't really know if it needs some kind of calibration.. As long as it's not hot to touch, you don't have to worry..

//Basel
« Last Edit: August 13, 2013, 09:07:12 am by baselsw » Logged

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The other thing - the SAM chips have an internal voltage regulation for the 1.8V VDDCORE, unlike the 8-bit AVRs.

I occasionally have access to IR cameras, so will take a shot of the chip and see if most of the heat is coming from a certain corner of the chip where the regulator may be.
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