USB drawing too much power

Projects General Guidance
1

Hi,I just started using the Arduino starter kit and while doing the knock lock project, I found that my mac had disabled my Arduino because it was "using too much power" I have tried restarting, shutting down and unplugging and plugging back in my Arduino and computer but nothing as been fixed, now whenever I plug my Arduino into my computer, my Arduino doesn't even light up! I can no longer upload any sketches to my Arduino either. Can somebody please help!?

2

Get a proper power supply, like a 9v wall wart.

3

You have either broken your Arduino or your USB port.
Can the USB port still be used on other things?

4

Hi,
Have you tried to power your Arduino up with a USB power supply, "wall wart". :o

Tom..... :slight_smile:

5

Just wondering if this could be remedied by using a powered USB hub. Anybody?

I've never had an issue with things drawing too much power through my current PC's USB ports but I do remember back in the days when I was running an Athlon, my front USB ports would complain about this a lot. My two ways around it were either using the USB on the back of the computer or plugging into a powered hub.

I'm not an expect but I think you shouldn't have to provide your 'duino with additional power when connected to your PC via USB. I've had many a robot try to jump off the side of my desk while new code is being uploaded.

6

I've done that before and fried an older mac notebook when they didn't have USB overload protection.

Check that your wiring is correct.

7

The USB standard calls for 500mA per port (1x USB Power).

  • Apple computers and displays with USB 1.1 or USB 2 ports provide:
    Up to 500 mA (Milliamps) at 5 V (Volts) to most Apple USB peripherals and all USB peripherals not made by Apple in compliance with USB specifications.
  • Apple computers with USB 3 ports provide:
    Up to 900 mA (milliamps) at 5 V (Volts) to most Apple USB peripherals and all USB peripherals not made by Apple in compliance with USB specifications.

The new PC motherboard usb port has more than 500mA.

  • 0.5 amps (1x USB Power) - the max current a typical USB port puts out
  • 1.0 amps (2x USB Power)- the minimum current an iPad needs to slow charge.
  • 2.0 amps (4x USB Power)- the minimum current an iPad needs to do its normal charge (ie same speed as the included wall adapter)

The new motherboard or supported old motherboard board which is upgraded firmware support more than 1x USB Power.

http://forum.arduino.cc/index.php?topic=152219.0

Confirming power usage in Mac System Profiler

8

Steverobey:
Just wondering if this could be remedied by using a powered USB hub. Anybody?

If the powered hub has adequate power, it is a reaonable alternative. Your call on "adequate", bearing in mind that the hub was probably not made with Arduinos in mind.

I'm not an expect but I think you shouldn't have to provide 
your 'duino with additional power when connected to your PC via USB

Well, some knowledge of the power consumption of Arduino projects might help before such a comment, but all you really need to know is that it is probably a lot more than a mouse and flash drive, and what works is entirely dependent on the power the computer makes available to the ports. If you find that your Arduino refuses to work after you have changed the motherboard in your PC, remember where you heard it first.