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Topic: Externally powering LEDs so Arduino doesn't fry (Read 5 times) previous topic - next topic

Grumpy_Mike

Reliability and electronic life time is a statistical thing. If you over stress the components then that life time gets shortened no question about that. However, seeing that with a sample size of one is impossible no matter if it carries on working until hell freezes over or it goes fut tomorrow.

Hippynerd

Well, technically just using the electronics shortens its life. so the only way to ultimately protect your electronics is to not ever use them.

Sample size has nothing to do with it. but if you say it can work until hell freezes over, then it sounds like specifications dont really matter.

CrossRoads

VCC and AVCC can each support 200mA - so 400mA total.
The ports should then be limited to 300mA:
3. Although each I/O port can source more than the test conditions (20mA at VCC = 5V, 10mA at VCC = 3V) under steady state
conditions (non-transient), the following must be observed:
ATmega48A/PA/88A/PA/168A/PA/328/P:
1] The sum of all IOH, for ports C0 - C5, D0- D4, ADC7, RESET should not exceed 150mA.
2] The sum of all IOH, for ports B0 - B5, D5 - D7, ADC6, XTAL1, XTAL2 should not exceed 150mA.
If IIOH exceeds the test condition, VOH may exceed the related specification. Pins are not guaranteed to source current
greater than the listed test condition.

So at 360mA, you're pushing it some.
Best bet is to use a couple of external shift registers such as TPIC6B595 that can sink the higher current amounts.
78 cents from avnet.com
https://avnetexpress.avnet.com/store/em/EMController/Counter-Shift-Register/Texas-Instruments/TPIC6B595N/_/R-1750249/A-1750249/An-0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1&page=1&rank=0
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

fungus


it sounds like specifications dont really matter.


You hear the words ... but you don't listen to them.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

Grumpy_Mike


Well, technically just using the electronics shortens its life. so the only way to ultimately protect your electronics is to not ever use them.

Sample size has nothing to do with it. but if you say it can work until hell freezes over, then it sounds like specifications dont really matter.

Why do you persist in being so resistant to trying to understand this subject? Those two statements are totally wrong. You have been told many times but you think that you know best. Let me tell you now, you don't.
The human propensity for self delusion never ceases to amaze me.

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