The white LEDs in the Charliewatch were probably not the right choice - their forward voltage is 3.0V, so once the 2032 or 2450 battery draws down a little bit they dim and turn off, even though the CC430 CPU will run down to 1.8V.

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@qrs you could have a little boost converter driven perhaps even by the micro, but it's too late now huh

@MightyPork I'll make another one with red or amber LEDs, which go down to 2V. Unfortunately the really pretty pink ones are also 3V.

@qrs ah yeah pink is usually just white with a special filter

@qrs higher, consistent temps on reflow would probably help surface tension align those LEDs more nicely. What size are those LEDs? I think I may have a pile of 1206 or 0804 red LEDs in my cabinet (had a spool at some point iirc)

@phooky Without a stencil it was difficult to apply evenly and the small-ish 0603 parts were quite a challenge. Several of the pads didn't have enough and the LEDs tombstoned, others slid around, and the CC430 part had quite a few bridges since there is no solder mask between pins.

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