LED dithering ? Power supply?

Hi

I have a lot of components on my breadboard .. and a RGB-LED :)

sometimes.. when I turn a potentiometer.. press a switch.. or just accidently touch the jumper-wires.. the LED dithers..

  • is it just because the jumper-wires in the breadboard fit a little lose?
  • or is that, because I feed my whole circiut with 3.3V ?? (I mean there are lots of 4051s, potentiometers, buttons, etc.)
  • I will need even more components.. should I use a external power supply?

Could be - we cannot tell.

What you can do is monitor your 3.3V supply at various points on the breadboard to see if it
is drooping due to the load and any poor connections. Breadboards aren’t really designed for
high currents, and the springs in the sockets can get stretched by thicker leads to become less
grippy for smaller leads.

So out with the multimeter!

Also are you using supply decoupling on each chip? 0.1uF ceramic per device, and its good
to have some bulk electrolytic decoupling if you are switching lots of current fast (LEDs perhaps?)

MarkT: So out with the multimeter!

ah .. good tip.. I will order one immediately :)

MarkT: Also are you using supply decoupling on each chip? 0.1uF ceramic per device, and its good to have some bulk electrolytic decoupling if you are switching lots of current fast (LEDs perhaps?)

What is supply decoupling ? oO Will have to learn about that :)

Certainly will :) - search these forums - Grumpy Mike has a guide to decoupling that often gets linked to.

thank you very much :)

..lots of learning for me.. but it's mega fun :)

Here it is:- http://www.thebox.myzen.co.uk/Tutorial/De-coupling.html

Also it sounds like you need to read this:- http://www.thebox.myzen.co.uk/Tutorial/Inputs.html

The LED dithering as you call it can be caused by floating inputs.

It is also possible that your breadboard has bad connections. I recently bought a board with four white breadboards on it, and they turned out to be garbage.

hey.. you guys rock :)

thank you very much for all the assistance ..