A. Wiggin

Member Since: January 11, 2011

Country: United States

  • I was looking through the hookup guide and in the section titled "Connecting to an Arduino or Compatible Board" and it very clearly states "Note that the LEDs are wired separately to each FemtoBuck! This is very important; the output of each FemtoBuck must be completely isolated from any other!" So if I understand your question correctly, I think that wouldn't work.

  • So after more datasheet digging I found that the CTRL internal resistance is 50 kOhm. Perhaps someone can verify my train of thought on this... since I = V/R = 2.5V/50 kOhm = 50 micro-amps? Is that the max current that would be sunk by the CTRL pin?

    And further, my supply voltage is 19.5V, if I drop it down through a 3.3V linear regulator and then use that voltage to control the dimming, would the power dissipated in the regulator be Watts = V * I = (19.5 - 3.3) Volts * 0.00005 Amps = 16.2 * 0.00005 = 810 micro-Watts. Does this sound right?

  • Does anyone know how much current the CTRL pin sinks when using it for dimming? My supply voltage is ~20V so I want to know how much power will be dissipated when I drop it down to 5V.

  • Thank you so much for leaving this comment!!! I bought these about 4 years ago and messed around with them but then put them aside. I just pulled them out again because I had a project idea for them but had no idea what firmware was on them and couldn't communicate with them at all. I flashed them using these recommendations and was able to get them up and running again!

  • After reading the comments I kept wondering why Robert was writing in all caps... then I realized why :-)

  • Or maybe there is a way to store more fingers to one user?

  • I'm a bit confused about the numbers (fingerprints stored and users)... in the description it says it can store up to 200 fingerprints but in the video the software can only store 20 "users" (which I take to mean "one finger"). Assuming that each "user" requires 3 fingerprints, that's only 60 fingerprints. Is the 20 users just a limitation of the software? I looked through the supplied datasheet but couldn't find anything.

  • It's interesting to me that there was a significant dip (about 50) in the weekly website visits before each of the Free Days. Thoughts on why?

  • Well, scotch tape isn't quite as classy as duct tape but as a wearer of glasses, I approve!

  • Are your glasses duct-taped to your mask BatBearSantaman? Classy.

No public wish lists :(