Hi. I am trying to finally get down to finishing my lightsaber project. I will be using the Instructables article with your Foxonix Project Board but instead of just using 4 individual buttons for the separate functions, I will be using sensors to detect the "swing" and "clash" events (to the Project Board the sensors will be the same as a switch - see :
abra-electronics.com/sensors/sensors-acc...n-sensor-switch.html
). Of course, I want to use LEDs for the lightsaber effect (see the Instructable at :
www.instructables.com/id/Darth-Maul-LED-light-saber/
) but I wanted to know if anyone would have an idea how to power strings of LEDs. I'm talking around maybe 80 LEDs, so 25ma x 80 LEDs comes to something like 2A of current total (.025 x 80 = 2 A).
I would have liked to separate the 80 LEDs into 8 strings of 10 LEDs, and control each of the LED strings separately but I don't think it will be possible, there are only 4 PWM pins on the Project Board. If I could do it somehow, I would light up each string of 10 LEDs in sequence so that when the lightsaber is turned on, the following would happen (String1 would be closest to the handle, String8 would be at the far end) : 1) to start with, all LED strings are off. 2) String1 fades from off to full brightness. 3) String 1 is now at full brightness, so, String 2 fades from off to full brightness. 4) Strings 1 and 2 are now at full brightness, so, String 3 fades from off to full brightness and so on up the blade to the end. If this is not possible, it is not a big deal, I will just fade in the whole string (of 8 strings) altogether at the same time. Which brings me to my real question : has anyone controlled anything of (relatively) high current with a Project Board. Maybe I could use a MOSFET? (I would have to find one that I can turn on with just 3.3 volts). Or maybe there is another programming function for the Foxonix board that would simulate/fake the PWM "Fade-in" effect which I then might be able to control 8 separate output pins? (e.g. a sort of variable Pulse Out function or something like that?)
If the 8 strings could be controlled separately, I would then try the following electronics : the 8 output pins of the Foxonix board would be connected to an 8 Channel Bi-directional Logic Level Converter (to up the 3.3V to 5V) which would be then connected to a ULN2803 (which contains 8 Darlington pair transistors) which would control the 8 LED strings.
As you can see, I am basically brainstorming before I get started wiring/programming anything. Any help would be greatly appreciated.
If I can get this working, I will be doing a Lightsaber project with my students at our trade school for CNC machinists in Montreal.
Everyone have a great day!
Regards,
Lorne Wilkins
