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

Date: August 16, 2011 5:44:00 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Guiding HW Addition

Hi Folks;

Here are preliminary images of the board I built, the PCB schematic for it, how it connects  the Hirose to RJ/12 cables and the Software interface to select it in Astro IIDC 4.07.01:

http://groups.yahoo.com/group/Astro_IIDC/files/Other/GPIOtoST4_Interface.jpg 

It's been a very long time since I had to work with components on PCB's, so my soldering "technique" is pretty questionable.

My local electronics supply house was out of PNP 3906 transistors, so I used low voltage 2N4403 ones which are equivalent. The ST4 interface is sort of weird because the motors turn if the voltage is 0 and stop if the voltage is high (5 volt) - which is why I went with PNP versus NPN.

I've verified the connections are behaving as expected using my multimeter and that the software works as expected, so it's off to the Acid test tonight.

I hope to try it out this evening on the HEQ5 mount after the sun slides further to the west and I can see the screen on my Laptop.

I'll keep you all posted.

TTYL..

Milton Aupperle