OpenWrt Forum Archive

Topic: Available current on GPIO lines on WL500gx?

The content of this topic has been archived on 30 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Post #1
leonardk
2 Jan 2006, 21:39

I have the Asus WL-500g Deluxe router, and there is a pin header J1 on the board which brings out three GPIO lines, 1, 3, and 5. Using the gpio utility I found here, I can easily turn these on and off using 'gpio 7 enable', for example, and I verfied with a meter that the voltage on these lines is 0 when disabled and ~3.21 when enabled.

Question is, what current is available on these lines? If I want to use one to turn off and on a solid state relay to press a shutter on a film camera, for example, can I directly drive the relay from the pin, or do I need a relay driver chip? I can't find a data sheet on the broadcom 5365 to tell me what's available.

Post #2
fusterjj
3 Jan 2006, 02:40

I would suggest buffering the output just to be safe.  You could probably just use a CMOS-type 7400 IC.  I would also check the requirements of your solid state relay against the buffer IC's specs.  Your router would be more expensive to replace than a buffer IC (:

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