Simple EPP IO board

[slavkok]

Hello...

As my machine happily run under EMC and parport driver now I'm runing out of pins.
Currently I have 3x3 pins to control 3 steppers (custom design with strange 3 wire interface) based on linisteper. Work perfect in halfstep/full torq with my 3V 3A steppers. It has power save function too (after 1 sec no moving the current is halved). Next I have spindle output relay with chargepump and chargepump enable all signal. Few limit and home switches and there are no free pins left. .. and as I use laptop there is no way to add another lpt. And of course all things is opticaly isolated from pc.

So as I want to extend this to one more motors (like to have two bipod for foam cutter) I'm in stage of designing board. For now I'm planed.

4 relays 10A/240V AC (all 4 operates as chargepump so false triger is not likely)
20 Digital outputs can be extended (up to 72 is possible but that's owerkill for software stepgen)
16 Digital input's can be extended (up to 80 but that's too is overkill for software stepgen)
EPP interface side opticaly isolated from other components. (20 cheap optocoupler's needed instead at least 32 if output side is isolated)
Material cost should be under 25Euro.

The board has only digital logic. No PLD's No CPU's Just Optocouplers 74HC4017, 74HC00, 74HC14,74HC573 and few discrete components.

Someone interested?

Slavko.

p.s.
I don't want to sell. When done all design will be posted on forum for free.

This is cross post from http://tinyurl.com/yj3zru9

[deny_jae]

sir...do you have a list of material (bom)?

please send me....

[slavkok]

I do not have BOM

But can be obtained from schematic.

The problem is that board as is doesn't work. I think that 4 wires are incorrect and I changed that in my board and doesn't draw corrections. ..and then the working board is sold and I have a lot of other job to do.

I do only one of that board as for other stuff i had just enought port pins.
Maybe Is worth to make one board for 8 (or 16) in and 16 out. That cover near all hoby machines. I wil do that if I need to do.