Bugs
Component bugs. These are hard to spot, because, as you can see, there are all sorts of components on your board.
They look like liquorice allsorts.
The ring of multicoloured LEDs neatly arranged, with some considerable effort and trigonometry, around the SCBP
are an example of the contents of Mrs Miggins' Olde Sweet Shoppe.
One of these was assembled rotated by 180 degrees. That meant that the output of the previous one
(for they are a daisy chain)
was feeding in to the output of the offending one.
The only thing preventing the prototype being the exhibit at the subsequent fire investigation
was the rather useful TPS2553-1, a clever one-shot shutdown device which puts on the red light
and cuts off the power until you press the reset button.
This also ensures the longevity of your USB supply in the unlikely event of you inadvertently
turning all those LEDs on full and connecting the 5V supply to your outside Christmas tree.
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