Well...  I found my problem.  I was looking at the board wrong.  I thought 
pin 1 was on the left, but it's on the right!  Ouch!

--Mark

On Friday, July 28, 2017 at 10:17:43 AM UTC-4, Mark A. Yoder wrote:
>
> I'm trying to wire an LED and 220 Ohm resistor to one of the GPIO pins on 
> the *GP0* connector of the Blue.
>
>
> <https://lh3.googleusercontent.com/-WykVt-aNYGE/WXtGLlRncpI/AAAAAAAA1UU/2eJYlRootHYQ3sb36XLUgTPr-TxCZgyowCLcBGAs/s1600/GP0.png>
> I measure 3.3V between the GND and 3.3V pins as I should, but when I hook 
> the resistor in series with the LED and attach them across GND and 3.3V, 
> the voltage across GND to 3.3V sags to 1.5V and the LED almost turns on. 
>  (If I dim the lights in the room I can see a little light from it.)  I get 
> the same result whether I'm powered off the USB, a 12V supply, or a LiPo 
> battery.
>
> How much current can the 3.3V supply deliver?  It seems I should be able 
> to drive an LED from it.  I can drive LEDs like this from the 3.3V supply 
> (and GPIO pins) on the Black.
>
> What's up?
>
> --Mark
>
>

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