Actions
Engagement
  • Author Author: tariq.ahmad
  • Date Created: Date Created
  • Last Updated Last Updated:
  • Views 35650 views
  • Likes 6 likes
  • Comments 6 comments
Related
Recommended

Driving LEDs to Create a Flux Capacitor -- DC to Daylight 08

In this episode we make a PWM LED driver using transistors and an Arduino Nano, which provide dimming and sequencing functionality for a Flux Capacitor. While not an exact replica, it does make a good demonstration of pulse width modulation and how to drive LEDs with a current sink/source

Supplemental Content:

Parents

  • Hello all! If you have suggestions on how to improve this project, especially related to software let me know here. One of the things I'd like to do is to "power up" three LEDs at the same time so the pulsing looks more natural... meaning three of the LEDs are actively ramping through the PWM values out of phase. I think this would require three nested loops and maybe a state machine. Ideas?

  • in reply to Derek (DCtoDaylight)

    If you stick all 5 brightness values into an array then you can loop through that array to drive the LEDs.

    You then do 'math' on the array to change the effect.

    e.g. for a comet tail type effect you might reduce all the current values of the array by 'x', then set the leading LED value to max.

    The values of the array then get written to the LED's at the next update.

    You again reduce all the current values of the array by 'x', then turn the next leading LED value on to full.

    By doing so you get a fade-out effect following the leading LED.

    You may also want to replace your 'blocking' delay() functions with non-blocking code.

    If you assign the value returned by millis() to a variable to store the current time (since boot), then later in the code check to see if the time now is greater that the stored time plus an offset value in milliseconds and only if so, then write the contents of the array to the LEDs. Finally update the stored value with the current time.

Comment
  • in reply to Derek (DCtoDaylight)

    If you stick all 5 brightness values into an array then you can loop through that array to drive the LEDs.

    You then do 'math' on the array to change the effect.

    e.g. for a comet tail type effect you might reduce all the current values of the array by 'x', then set the leading LED value to max.

    The values of the array then get written to the LED's at the next update.

    You again reduce all the current values of the array by 'x', then turn the next leading LED value on to full.

    By doing so you get a fade-out effect following the leading LED.

    You may also want to replace your 'blocking' delay() functions with non-blocking code.

    If you assign the value returned by millis() to a variable to store the current time (since boot), then later in the code check to see if the time now is greater that the stored time plus an offset value in milliseconds and only if so, then write the contents of the array to the LEDs. Finally update the stored value with the current time.

Children
No Data