Total Arduino noob here - excited to be tackling my first project. I'm trying to determine if I can do what I need with a Nano, or if I need to step up to an Uno.
My application is fairly simple - I'm building a stepper control for a simple ball screw linear "pusher".
The stepper I've chosen (closed-loop NEMA34) comes with a digital stepper driver and 60v PSU, so that's all sorted.
The screw will include limit / home via hall sensors.
The analog controls I'll add are fairly minimal:
a momentary switch to bump the screw in one direction ("forward")
a pot to alter the speed of the above
a "run" button that will move the screw forward (at the speed set by the pot) to the "far" limit
a "rapid home" button that will move the screw back to "home" rapidly
a stop or e-stop button
Eventually I will add a simple display - just something to indicate speed of the screw feed rate.
It's literally never going to get any fancier than this - I just need to drive a table into a machine at a slow rate, stop, and return on command only. MAYBE I would add buttons for "slow" "medium" and "fast" predetermined feed rates, but really the pot will give me that.
It's a closed-loop stepper - but my understanding is that none of the "feedback" is used externally, it's all in the stepper/driver.
I think a nano will do - but my concern is the things I don't know I'll need
In addition to that driver, you will also need a power supply (30-80V) that can supply however much current your stepper will need. You will also need another power supply for your arduino (5V) which could just be a wall-wart/phone charger.
Finally, make sure you have your ground wires all tied together. A very common mistake people make it to power their drivers/sensors/etc and not tie the ground back to the arduino so things don't work.
If you are programming a stepper on Arduino, check out my tutorial on Multi-tasking in Arduino which has a complete stepper example controlled by user input and a temperature sensor.
It uses the AccelStepper library and covers how to ensure the library run() method is called often enough to get the speed you desire.
There also another project Stepper Speed Control Library project with plotting which has a modified library that controls speed rather then position
If you are controlling a machine there may be regulations for E stop in your Country involving checking of contacts at startup and reliability criteria .
You got that backwards! In no way is a UNO a "step up"!
While the Nano and UNO are programmatically the same since both are based on the ATmega328, for a "real world" project, the Nano is the more appropriate as without header pins fitted, you are able to solder connections to the board or with the header pins fitted you can insert it into a "solderless breadboard" or a "terminal shield" or your own custom PCB.
The UNO has only socket headers fitted in an odd arrangement, it is suited to being fitted with custom-designed, pinned "shields" but connections are otherwise insecure.
Since the proper way to power either is with regulated 5 V to the "5V" pin - you should not power it by "Vin" or the "barrel jack" on the UNO, you need to be careful specifically on the UNO, to disconnect the power to the "5V" pin when connecting via USB to a PC. The Nano does not have this problem.
In no way is a UNO a "step up"!