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pdiefend
04-01-2010, 08:47 AM
Has anyone ever considered utilizing the power from your computer's USB port to power a Basic Stamp or other microcontroller. Only while you are programming and testing the circuit, or when you are using a base transmitter connected to your computer, or some other low current draw circuit that needs to be connected to the computer. I have been looking around on the internet for a while, as well as these forums and have not found anything about it. I don't about you guys, but I'm tired of going through batteries while testing programs or using lower current draw (no motors or anything too strong) circuits when I could be using my computer's USB for power. The one thing that I am looking for is either a device that you may have seen that does this or a circuit that can be made. This does not have to be limited to the Basic Stamp and it can power other microcontrollers and circuits too.

Thanks
pdiefend

Forrest
04-01-2010, 09:15 AM
Parallax sells a Basic Stamp board that runs off the USB port www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/CategoryID/9/List/0/Level/a/ProductID/118/Default.aspx?SortField=UnitCost%2cProductName (http://www.parallax.com/Store/Microcontrollers/BASICStampModules/tabid/134/CategoryID/9/List/0/Level/a/ProductID/118/Default.aspx?SortField=UnitCost%2cProductName)

allanlane5
04-01-2010, 09:18 AM
The problem with this is that USB ports are often off battery-powered laptops, so you don't want to draw down the laptop battery. Also, a wall-wart is really inexpensive, and provides up to 1 amp, with no drain on the laptop. With many designs, a wall-wart is simply much more appropriate.

silverback
04-03-2010, 07:17 PM
I actually woke up thinking of this very possibility. I use a BOE Rev C and the board is rated at 6-9V. The maximum I could draw from a USB is 5.25+\-

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
If you convince yourself that something is impossible before you even try; you are sure to prove yourself right.

silverback
04-03-2010, 07:17 PM
I actually woke up thinking of this very possibility. I use a BOE Rev C and the board is rated at 6-9V. The maximum I could draw from a USB is 5.25+\-

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
If you convince yourself that something is impossible before you even try; you are sure to prove yourself right.

sylvie369
04-03-2010, 09:45 PM
Just FYI, the BS2pe MoBo can also run off of USB power:

http://www.parallax.com/Store/Microcontrollers/BASICStampDevelopmentBoards/tabid/137/CategoryID/12/List/0/SortField/0/Level/a/ProductID/451/Default.aspx

The schematic at the end of the manual for that product might help you figure out how best to do it.

TonyWaite
04-04-2010, 04:46 AM
Hi,

I usually use a cheap USB hub if I'm sipping power from the Laptop. Because it's
much cheaper to blow a £10 hub than the USB chips on the Motherboard ...

T o n y

JimK
04-04-2010, 08:48 PM
This might work...· a·cable that adapts from a USB port to a 5.5x2.1mm barrel connector, center positive

http://www.sparkfun.com/commerce/product_info.php?products_id=8639