From: "milton_aupperle" <milton@outcastsoft.com>

Date: August 22, 2011 9:00:09 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Guiding HW Addition

Hi John;

Your right, it should have been NPN. I have corrected it in the final schematic layout here:

http://groups.yahoo.com/group/Astro_IIDC/files/Other/GPIOtoST4_InterfaceV3.jpg 

Note that you also need to connect the Cameras ground (Pin 5) to the ST4 ground (Pin 2) or the GPIO pins won't "trigger" properly, which has been added to the Version 3 layout.

I also included an image showing the final product (in a plastic enclosure box) mounted on the scope.

I still have testing to do, but so far it shaping up to work really well.

Thanks..

Milton Aupperle

--- In Astro_IIDC@yahoogroups.com, "John" <jbuckley1@...> wrote:

Hi Milton, 

I was looking at the V2 interface jpg and I had a question as to the 3904 transistor. Should the part list it as NPN instead of PNP?

Clear and steady skies,

John B.