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Member Since: January 7, 2010

Country: United States

  • Just thought I’d comment: The LED strand isn’t as listed in datasheet, it’s 100 individual leds in parallel.

    I hooked the LED strand up to a CC/CV benchtop supply, without the current limiting resistor, so I’m applying a semi fixed voltage across the two conductors/all the LEDs

    • At 2V (0.05A), only the reds are on
    • At ~2.3V (0.09A - 0.13A), the greens start coming on
    • At ~2.5V (0.15A-0.18A), green is full on, and blues start activating
    • At ~3V (0.34A-0.38A), blue seems fully on, and it looks good/decent.
    • At 3.5V (0.5A-0.6A), still looks good, is bright while coiled
    • At 4V (0.8-0.9A), relatively bright, probably being overdriven; was able to run like this for a few hours with no ill effects.

    To get outside of the ‘only red led zone’, you need to choose a target voltage, account for the voltage lost in the resistor for the given current, and then supply that…… assuming the resistor doesn’t catch fire (if the resistor was more then an ohm, I don’t think it has the power dissipation to handle 0.3A) . I would do the calculation, but alas I threw the resistor away, and don’t know its ohm value.

  • Can you be more specific about what’s going wrong? I might have run into the same issue as you have. In my case, when I first compiled/loaded the firmware, the atmega238 would reset every 1/3 second; so, it didn’t initially seem like the buttons would work.

No public wish lists :(