I'm working on an all in 1 controller and would like to incorporate a pendent for jogging and such. The controller will be running GRBL and hopefully sport an SD reader. With that said I plan to use 2 Arduino 328p IC's, one to run GRBL and the other to control the SD side of things. So to the case at point, I was thinking for the jog, could I not build a pendent that with a push of a button would set the step/direction pins of said driver high or low instead of doing it software based. That would be a lot easier but I fear of back feeding to the Arduino's pins when the pendent sends the 5v to step/dir. Would say a diode in line with the Arduino pins prevent this issue?
Hi Robert. Sounds Great! Being New to CNC I actually couldn't believe the number of different controller/driver/break out solutions that exist out there - and still haven't found one that is right for me (maybe this will be it!). I actually think doing the jog in software would be easier. It would be very straightforward to hook up a joystick controller (search ebay for "arduino joystick" to see what I mean) to a couple of analog pins on your SD Arduino which will have a lot of spare bandwidth. Then you could vary the speed and direction according to the rotation. Actuating the push button could be useful too (home?). I guess you already have a communication path set up between the 2 IC's for the SD data, so you could convert the analog joystick signal into stepper instructions quite easily. I was thinking of my own controller too - I wanted to support GRBL and parallel port so that I can figure out which software to use!
This is really where I hit a wall in that I know very little when it comes to programing. I can make the PCB's no prob but find myself building around the software as modding it or writing my own is just out of my league right now. I end up hacking most of my scripts and I'm sure they are full of crap that is not needed but they function the way I want Right now I have all the IC's and have decided to go with the TB6600 as the driver chip. I have tested the single axis boards with an arduino and they worked real well. Now it's just a matter of meshing things into a single board lol
You want to use a tri-state buffer for the scenario described in your first post. These are built in to the microcontrollers you're using. The code to use these will be quite simple. You can also get them as a separate chip and avoid the code change altogether.
That is just what I was looking for Ty so much, starting to think a few more hands into the design of this controller would be a good thing as I'm so busy building and milling OX plates for members. I have the ability to make the boards but the time to mesh all the test hardware into the board design is killing me lol. Got all IC's needed yesterday, waiting on the SD / FTDI bobs and now need to decide on a tri state buffer that will suit the need. Seems very simple almost the same as my hardware de bounce for the uv pcb controller I made
It’s a really hard thing to get other people involved in in a project like this. They won’t share your vision or your stakes in the project. Best to take it slow, and find people that can help you in specific circumstances. For what it’s worth.