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Topic: Analogwritemega problem. (Read 584 times) previous topic - next topic


I'm working through the examples trying to get to grips with the basics and have come across an odd problem.

I hit a wall yesterday and dis-assembled everything.  I sat down again today and had another go and encounter the same problem.  I have checked the wiring carefully.

The example should light 12 LEDs, 2 - 13 one after the other.

Only 2 - 7 light.  Then there is a pause long enough for 8 - 13 to light, but they don't and the sequence starts again at 2.

I removed wires 8 - 13 (the non-functioning LED supplies) and 2 - 7 continue to run.

I move the supply for LED 7 to output 12 on the mega and 2 - 6 light properly and then a wait sufficient for 7 - 11 to light and then 7 lights.

If I feed the outputs 2 - 7 to LEDs 8 - 13 I get nothing.  Is it possible to have a faulty breadboard?

Everything seems to point at it.



What is your sketch ? Do you use resistors with those leds ? 12 * 20 mA = 240mA, you use the 5V pin for that ?


Mar 06, 2015, 03:58 pm Last Edit: Mar 06, 2015, 03:59 pm by johnwasser
Note that many larger breadboards have the power rails split at the mid-way point.  This is usually shown with a break in the red and blue lines that show the connections of the two power rails on each side of the breadboard.  Jumper those gaps if your are using both ends of the breadboard.

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Thank you so much.  Not a malfunctioning board then.  A malfunctioning brain.  I'd even connected the power rails on ONE side of the board before posting.....  DOH!

Thanks for your help.

I'm going to learn to tie my own shoelaces tomorrow.



Is it possible to have a faulty breadboard?
It's rare for a breadboard to not have things connected that should be connected.

It's very common for a breadboard to make a poor (intermittent) connection, though. I try to avoid using them.
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