I'm putting together a very simple single stepper motor setup using an EasyDriver board and a Nano.
I will have four different 'stop' controls - two microswitches, the centre position on a direction switch, and an emergency stop button. I can set the 'Enable' pin on the EasyDriver high to stop any output to the stepper. I envisage all these being separate 'normally open' connections, and the stepper motor must stop if any one or more of these controls fires.
I have done plenty of programming but only have a limited knowledge of electronics (I can wire and solder however!)
I think one solution may be an 'OR' logic gate, like the 4075, but I am finding it hard to find one similar with four inputs.
So, two questions -
can you chain logic gates together? If so, using three two gate ones would presumably work.
are there other, simpler ways to wire what I'm trying to do? In my limited understanding I'm thinking that simply wiring them all back to the same point would cause too much voltage to the Enable pin if two controls went off at the same time (2 x 5V for instance). Or maybe this isn't the case? Sorry to be so ignorant of basic theory!
Of course, any other advice gratefully received! Thanks.
it will be 5V. Voltage is the difference in potential versus a reference (GND). If you close two switches, all the points on the wires are basically identical, so carry the same potential (if you ignore the resistiveness of the wire on short distances)
In a simplistic view, if current is flowing through the switches then current will be added.
The emergency stop should be a normally closed switch that removes the power when activated, and latches in the operated condition.
You should not rely on software for an emergency stop.
