The SparkFun Stepoko is an Arduino compatible, 3-axis control solution that runs grbl software and is able to connect to your computer to accept stepper motor commands. The Stepoko’s design and firmware are completely open source and it works with an open source Java based cross platform G-Code sending application to translate commands. By just looking at the pictures this board may look daunting but the simplest installation of the Stepoko consists of just plugging the stepper motors in, connecting it to power and to your computer! To top it off, we’ve designed the SparkFun Stepoko to fit and be secured inside of our Big Red Box as an effective enclosure option after a bit of milling to support the boards connectors and heatsink.
When looking at the SparkFun Stepoko it will be very easy to differentiate the two “hemispheres” of the board. The right side of the board has been dedicated to supplying power and system control. At the heart of the Stepoko is an Uno compatible ATmega328p. We’ve broken out all of the pins that are associated with the microcontroller and power supplies and an included chart in silkscreen on the back of the board that matches the grbl pin functions to the Arduino pin naming convention. Apply 12-30VDC to either the barrel jack or screw terminals (not both) and the Stepoko can supply up to 2.0A! Additionally, you will find a rail of screw terminals that function as Limit, Probe, E-Stop, etc connections.
Meanwhile on the left side of the board we can find all three of the stepper motor drivers for the SparkFun Stepoko. Each of the three axis drivers are controlled by a DRV8811 IC. The ATmega328p on the right side of the board talks to the 8811 by digital control signals that are able to set direction, enable the motor, and enact a step. Internally, it has a state machine that matches the states of each motor necessary to get it to perform. Modifying the Microstepping Control switches on each driver provide you to finely tune each array to your specified likeness. All the work that each stepper motor driver provides is contributed by the grbl software that comes pre-installed with each Stepoko. This new revision updates the firmware to the latest version (0.9j). We’ve also added a piece of thermal gap filler to help electrically insulate the board from your chassis and prevent problems from ESD.
Whether you are using the SparkFun Shapeoko on your own rig or on one our Shapeoko CNC Machine platforms you should be able to utilize this board to its full functionality without breaking a sweat!
Here is the Arduino pin map:
D0- RX D1- TX D2- STEP X D3- STEP Y D4- STEP Z D5- DIR X D6- DIR Y D7- DIR Z D8- STEP EN D9- LIM X D10- LIM Y D11- SPIN PWM D12- LIM Z D13- SPIN DIR A0- RESET/ABORT A1- FEED HOLD A2- CYCLE START A3- COOLANT EN A4- UNUSED A5- PROBE A6- UNUSED A7- UNUSED
This skill concerns mechanical and robotics knowledge. You may need to know how mechanical parts interact, how motors work, or how to use motor drivers and controllers.
Skill Level: Experienced - Your experiences should include working with stepper motors and feedback system. You may need to understand how encoders and more complex control systems work.
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Whether it's for assembling a kit, hacking an enclosure, or creating your own parts; the DIY skill is all about knowing how to use tools and the techniques associated with them.
Skill Level: Noob - Basic assembly is required. You may need to provide your own basic tools like a screwdriver, hammer or scissors. Power tools or custom parts are not required. Instructions will be included and easy to follow. Sewing may be required, but only with included patterns.
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Based on 4 ratings:
This board is very versatile.
I’ve got two of these now, not for CNC, but as a general purpose motor controller. The documentation is nice and clear. Board quality is good, and the forums were helpful.
I think this is a very good product but is a bit expensive when you have to replace it. A more modular design would have been better for the customer. I say this because the first unit I had took a static charge and died so I had to replace it. To counter act the static issues I have tied everything on my Shapeoko to earth ground which has helped keep this guy alive for now.
Things that could be better:
- Connectors are too small. If they were removable it would be better but larger ones would be nice as well.
- The Y-Axis could have been broken out into two inputs to make hookup on the Shapeoko easier
I got the Stepoko as part of a full Shapeoko kit. It may be a fun board for experimenters because of all the switches and LEDs, but for just doing CNC its less that desirable. Mine blew a channel in the middle of a job after about 2 months of fairly light use. Repair took 4 weeks (with shipping) because they actually have the tech hand solder new parts on the board because it doesn’t use pluggable drivers like a lot of controllers. I got the impression that having to repair driver chips on this board was a fairly regular event–it runs very hot.
The worst part is the support. Most of the techs at Sparkfun don’t know CNC so their replies to questions are usually a long diatribe about the board “not being designed for that” (which actually translates to “I have no clue”). It took me a couple of weeks of back and forth to get it to do homing which is a primary function of grbl. Not a great user experience for a high priced part.