Could you not sort this on the current led with diodes?
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Andy Burns" wrote in message
...
I've replaced the motherboard in a PC with a small SBC which has an intel
9-pin front panel connector[1] rather than just a bunch of header pins for
LEDs and switches like a normal motherboard, the connector pins are
labelled in the board's own manual[2] as

1 HD_LED_P
2 PWR_P/SLP_N
3 HD_LED_N
4 PWR_N/SLP_P
5 RST_SW_N
6 PWR_SW_P
7 RST_SW_P
8 PWR_SW_N
9 UNUSED

so the power LED is between pins 2 and 4, and rather than a single on/off
LED, it offers the ability to use a bi-colour LED.

The way they're labelled PWR+/SLP- and PWR-/SLP+ I assumed it required a
2-pin LED with red/green wired in inverse parallel, such as

https://www.maplin.co.uk/p/twopin-qy83e

I bought one, it lights up green when power is on, but not red when power
is off (by reversing the connections I can make it light up red when on,
but still not green when off, so it isn't a case of the LED being half
dead).

Presumably this means in reality it requires a 3-pin LED, such as

https://www.maplin.co.uk/p/threepin-cj53h

And that I need to split the ground from e.g. the hard disk LED cathode
pin to feed the power LED's common cathode, the labelling feels wrong
though ... would you have read it the way I did initially?



[1] http://www.formfactors.org/developer%5Cspecs%5Ca2928604.pdf
[2] http://download.udoo.org/files/UDOO_X86/Doc/UDOO_X86_MANUAL.pdf