avatar

AndrewMV

Member Since: March 2, 2010

Country: United States

  • Why is a BJT inappropriate (not challenging you - I’m curious)?

  • USB A to A? That’s a pretty dangerous thing to give someone - if they connected two PCs together, they could blow up the USB controller on one or both of them.

  • These LED’s consume more power than any microcontroller could output without some amplification. Per the datasheet, typical power consumption is between 350mA to 700mA per LED - compare that to the 10-20mA of a typical LED.

  • Easily among the best video-production quality I’ve seen in a build demonstration…and the cabinet built around the device is just perfect :)

  • I love this idea…it’s like a robotics version of the Rube Goldberg competitions.
    How about a robot who’s purpose is to press its own kill switch, which is suspended 30 feet in the air?

  • I spent some time looking at the TLC594X series LED drivers, and they seem to have a lot of potential…but they all operate as current-sinks instead of current-sources.
    I’m still new to this, but it seems to me that these wouldn’t be usable for a common cathode display like this (you’d need a common-anode display).
    Does this sound right? Is there an easy way to compensate for this that I’m missing?

  • Flip it pins-up. Orient the serial number rightside-up. Pin #1 is on the bottom right. Pin #17 is on the top-left.

  • On mine, the color and intensity are perfectly uniform on all the colors. Are you using current limiting resistors on the cathodes?
    An odd thing I almost missed on the datasheet - the green and blue LEDs are 3.3V, but the red ones are 2.0V (2.2max!). You’ll need to put a voltage divider on the red pins.