Looking for detailed info on the TinyG

Home Forums TinyG TinyG Support Looking for detailed info on the TinyG

Viewing 6 posts - 1 through 6 (of 6 total)
  • Author
    Posts
  • #5055

    Greetings!

    I just received my TinyG last week and I’ve spent a lot of time poking around the wiki and all the online resources etc, but one thing I have not been able to find is anything detailing all the jumpers and headers etc on the board and what their purpose is and voltage/current ratings are etc.

    Does such a thing exist? If so, could someone kindly point me in the right direction?

    I will say I haven’t powered up my TinyG yet, still waiting on a proper power supply and cabling, so I’m trying to track down all the documentation I can as I wait 🙂

    Thanks!

    #5056
    cmcgrath5035
    Moderator

    Always good to specify what version you have; if you just received, then probably V8.

    Did you find this URL ?

    #5057

    Yes, it is indeed the v8, sorry for the oversight.

    I did find that diagram, but I was hoping for something a little more detailed.

    Here’s a little info on my planned project, perhaps that will give an idea of what I need.

    I preordered the Shapeoko 2 mechanical kit and am planning on making a semi-portable laser cutter. Well, laser etcher is probably more accurate for now as I only have a 1.5W 445nm laser currently. I have a Raspberry Pi and a TinyG v8 for control and they will be put in a small case and mounted on the Shapeoko somewhere.

    One of the difficulties is control of the laser on/off and there are lots of solutions out there, but it occurred to me I could simply take the Z-direction output signal from the TinyG breakout header and feed that into a transistor, used as a switch, to switch the laser power on and off. The idea being I can generate gcode as usual, but just make sure the Z-axis travel for rapids etc is a very small amount, 0.01″ or so, so the laser stays in focus, but also moves just enough to get the direction pin to change from 0V to 3.3V and vice versa.

    My laser driver will use 24V @ 1.8A (though I may drop that to 12v @ 1.8A if heat becomes an issue) and I was wondering what the Z-direction signal is so I can pick a transistor appropriately. It is 3.3v I believe, but what’s the mA output?

    So all I need for now is that one little bit of info, but the more info I can collect, the more possibilities open up for future projects 🙂 I could also be barking up the wrong tree with my idea, but if it works as I envision, it would be a nice simple solution.

    If I need to clarify anything, please let me know.
    Thanks!

    #5060
    cmcgrath5035
    Moderator

    Sorry, you are probably going to have to wait for Alden to weigh in, My ShapeOko is pretty much focused on milling.

    X,Y,Z and A max and min are for limit switches. Coolant and SPIN(dle) are controllable from GCode (on/off), but I’m not sure that is what you would need to control your laser.

    I’m not sure what you mean by “Z Direction Pin”.
    A1, A2, B1 and B2 are servomotor winding drivers.
    I believe they output full(nearly) input supply voltage to the windings, based on current limiting setting of the Current Trim Pots.

    #5061

    No worries, I appreciate you taking the time to chime in!

    On my v8 board there spots to solder on headers for the Enable, Direction and Step signals for each stepper. I gather from the wiki and various forum posts that they are intended to be used with external stepper drivers, in case you want to use more powerful steppers than the driver on the TinyG will allow. I am hoping to use the direction signal from my Z axis stepper driver on the TinyG to control the laser turning on an off. Z axis moves up, laser goes off. Z axis moves down, laser goes on.

    But I may have answered my own question, at least with regards to the transistor. If I use a MOSFET, they are voltage driven, not so much current, so I don’t think I need to know the exact current rating of the pin. An N-channel MOSFET like this one for example http://www.adafruit.com/products/355 can apparently switch off of a 3.3V signal and switch up to 30V@60A which is more than plenty for my application.

    Well, back to Google to see what else I can come up with 🙂

    #5064
    alden
    Member

    You might look into the Spindle PWM output. This is settable in SW (use the JSON commands). It would need to be gated for use in a laser cutter. The enable might work as you suggest, or you might need to hack the code a bit more.

    There is a lot of info on the wiki about setting up environments, programming, etc. The code is also pretty heavily documented if you get in that far.

Viewing 6 posts - 1 through 6 (of 6 total)
  • You must be logged in to reply to this topic.