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[Reply #15 on:]

Reads like an "advertisement" more than an "article" to me.

My strategy is to use ATMega328 chips that cost $2 each from Digikey instead of Arduinos.  Doesn't hurt as much to mess one up.  And you can set the fuses any way you want, use the internal oscillator and free up 2 pins, retask RESET, etc.

[Reply #16 on:]

You need a separate power supply / driver that is controlled by the arduino. Could be as simple as a logic-level MOSFET for each LED.

Can I use shift registers (e.g. 74HC595) instead to solve the same problem?

Why not use a proper LED controller. They work just like a 74HC595 but you don't have to worry about resistors - it's all in the chip.

[Reply #17 on:]

Hi All,

I'm a beginner to Arduino, and I'm very nervous whenever I connecting pins with wires.  I came across an article "10 Ways to Destroy an Arduino" in the internet.

Yes, but most are unlikely.

Remember: You can usually fix your Arduino in five minutes with a $3 replacement chip.

[Reply #18 on:]

Remember: You can usually fix your Arduino in five minutes with a $3 replacement chip.

"five minutes chip replacement", interesting, it really rings the bell.  Can I have more information about how?  I'm willing to do soldering, though I'm lousy in soldering.

[Reply #19 on:]

Just buy a new bootloader chip from Adafruit or Sparkfun.

http://www.adafruit.com/products/123

[Reply #20 on:]

I'm a beginner to Arduino, and I'm very nervous whenever I connecting pins with wires.  I came across an article "10 Ways to Destroy an Arduino" in the internet.  I'm just wondering, are all the pitfalls mentioned in the article true? (Obviously, the author of the article has a conflict of interest.)

All of them are very real! And I have experienced most of them myself in one way or another. I buy Atmega 328p chips (the CPU on the Uno) in quantity 25 from Digi-Key, so each cloud of magic smoke only costs me $1.98 :-) I do crazy things like build my own H-bridges for 15A motors, though, and I'm also known to accidentally put down soldering irons on energized boards. 

If I had known about the Ruggeduino when I started out with Arduinos, I'd probably have gotten one of those instead.

Note that the "conflict of interest" with the author might not be all that bad. It's not like he's trying to scare you into buying his version. It seems to me like he knows how things can go wrong, and because he specializes in ruggedizing circuits (I think he's a consultant) he's using the Ruggeduino as a showcase of what he can do. Also, as the Arduino really is aimed at a wide variety of skill levels, I'm a little miffed that the Arduino guys themselves didn't add those protections. At the volume that Arduino Unos are selling these days, that probably would have been very cheap...

[Reply #21 on:]

Just buy a new bootloader chip from Adafruit or Sparkfun.

http://www.adafruit.com/products/123

Opps... how can I miss something that obvious?!  Thanks.

[Reply #22 on:]

I just discovered jameco.com is also selling Arduino bootloader chips now. Go to the
website and request their catalog by mail. 10,001 different electronics parts.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2129334_-1

[Reply #23 on:]

As for 10 LEDs...  I'd buy bright LEDs and run them at lower current.  10 LEDs at 5mA each would be no problem.

[Reply #24 on:]

Remember: You can usually fix your Arduino in five minutes with a $3 replacement chip.

"five minutes chip replacement", interesting, it really rings the bell.  Can I have more information about how?  I'm willing to do soldering, though I'm lousy in soldering.

1) Pull broken chip out of Arduino
2) Put new one in.

No soldering needed.

[Reply #25 on:]

Here is a link to a video of a simple project with a total of eighteen (18) LEDs.

Nothing burned or even got warm.

Maybe I'm lucky? Or maybe all the LEDs have to be on one output...

http://youtu.be/V1SyCLw40U0

[Reply #26 on:]

I just discovered jameco.com is also selling Arduino bootloader chips now. Go to the
website and request their catalog by mail. 10,001 different electronics parts.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2129334_-1

A very good way to get a couple.  But you can get those chips for $2 each from Digikey if you buy 25, put the bootloader on yourself as an evening project.

[Reply #27 on:]

Nothing burned or even got warm.

That's what you think...

[Reply #28 on:]

Very curious about how the damage would manifest? Do I need to worry?


Here is what the ARDUINO REFERENCE says about the UNO...
Input and Output
Each of the 14 digital pins on the Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms.

The LEDs used are rated at:
Max Continuous Forward Current : 30mA
Max Peak Forward Current : 75mA

The ATmega328P datasheet (page 303) says:
29.1 Absolute Maximum Ratings*
29.2 DC Characteristics
Operating Temperature.................................. -55 C to +125 C
Storage Temperature ..................................... -65°C to +150°C
Voltage on any Pin except RESET
with respect to Ground ................................-0.5V to VCC+0.5V
Voltage on RESET with respect to Ground......-0.5V to +13.0V
Maximum Operating Voltage ............................................ 6.0V
DC Current per I/O Pin ................................................ 40.0mA
DC Current VCC and GND Pins................................. 200.0mA
*NOTICE:
Stresses beyond those listed under “Absolute
Maximum Ratings” may cause permanent damage
to the device. This is a stress rating only and
functional operation of the device at these or
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect
device reliability.

[Reply #29 on:]

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage

That's all you get to know.  Without relatively sophisticated testing, you might never notice (in which case, is it really damaged?)
From reports that I've seen, more people are abusing their AVRs and having them appear to survive (ie by driving LEDs directly with no current limiting resistors), than are having their AVRs die from momentary overloads.