how many LED's can a BOE power at once?

Jayguy5000

I have some super bright LED's 8000mcd and Im using them with the resistors they shipped with, which are either yellow brown brown or yellow violet violet. Its really tough to tell. Anyway I am wondering what math formula would I use to figure out how many LED's the boe can power at once. does it matter if I use a 9v battery or 4aa?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Actually I think Im going to add the whiskers to my tank and let it roam, just need to figure out where.

sam_sam_sam

Here use this it might help

http://www.the12volt.com/ohm/page2.asp



Did you buy these leds on ebay if you did most of the time at lest the one that bought they are set up to run on ether 9 volts or 12 volts


▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
··Thanks for any··that you may have and all of your time finding them

·
·
·
·
Sam

Tech-Man

I used to know this formula but I know id mess it up. But I can tell you that it depends, are you asking how many off each I/O port or simply off the VDD and VSS power lines. Use a DMM for testing your resistors. But I’m guessing it’s 410 Ohm because yellow, violet, violet would be huge. I think???

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
There are no Undo buttons in life.

Mike Green

Any one I/O pin can handle up to 25mA. A group of 8 I/O pins (P0-P7 or P8-P15) can handle up to 50mA total (for all 8 pins). The total device can handle about 100mA including its own power needs.

This is for the BS2. Later models of Stamps use a different microprocessor (the SX) and have different rules for I/O current.