"wadd" wrote in message
om...
Can anyone tell me what the +5 signal return wires and so on are for,
I am trying to assemble a kit that I purchased from Dan at Camtronics
(great guy), I am new to all this so please don't laugh too hard.

The inputs of the Gecko controllers (the step and direction signals) are
optocoupler isolated. You take a pin from the parallel port for each signal
(1 for step and 1 for direction). And the +5V from the PC connects to a
third terminal on the Gecko controller that I think is labelled +5V or
something like that.

In the optocoupler (one for each of the step and direction signals), is an
LED and a light-sensitive switch. In the Gecko controller, the step or
direcion signal is connected to the cathode side of the LED. The +5V is
needed for the anode of the LED. When the PC drives the step and/or
direction signal low, current flows from the PC's 5V through the LED and
causes the LED to light inside the optocoupler. This light turns on the
light-sensitve switch. When the step and/or direction signal is no longer
driven low, current stops flowing through the LED and the light-sensitive
switch will turn off.

This type of circuit allows the Gecko controller to be completely
electrically isolated from the PC. The signal is transmitted optically from
the PC to the controller. They do not need to share a common ground
reference...in fact you *shouldn't* try to tie your PC's ground to the power
supply grond inside the camtronics box.

There is a wiring diagram on the camtronics web site if I remember
correctly....it should show everything you need. I'll post a link if I find
it.

Todd