Brushless DC Motor Driver
This project was inspired by shortcomings of stepper motors, used by almost all 3D printers. Brushless DC servos and controllers exist, but they are expensive and designed for industrial applications. My goal was to bring a similar technology to a smaller and more affordable level, allowing for use in 3D printers.
My design uses a controller with an integrated Atmel ARM processor with a L6235 motor controller to offload some processing from the main chip. A Nema 17 frame brushless motor was paired with a 1000 tick/rev encoder for high resolution and the ability to bolt to existing Nema 17 motor mounts.
The project went through a few prototype cycles. First, I used an Adafruit Feather to write a script to control mosfets directly. This had some severe shortcomings due to the overhead of the Feather causing very slow responses. Next, I switched to using an L6235 with the Feather, which worked pretty well and I was finally able to get basic servo'd control working. Finally, I designed and ordered a PCB which I populated myself, with help from my other project, The Toaster Reflow Oven. With this board I was able to once again achieve basic servo'd motion, although I realized at this point you really need the resolution of direct mosfet control, and with a mcu programmed from scratch this would be much faster than using the Feather. In the future, I plan to modify this existing design to go back to using mosfets and give this one more go.
My design uses a controller with an integrated Atmel ARM processor with a L6235 motor controller to offload some processing from the main chip. A Nema 17 frame brushless motor was paired with a 1000 tick/rev encoder for high resolution and the ability to bolt to existing Nema 17 motor mounts.
The project went through a few prototype cycles. First, I used an Adafruit Feather to write a script to control mosfets directly. This had some severe shortcomings due to the overhead of the Feather causing very slow responses. Next, I switched to using an L6235 with the Feather, which worked pretty well and I was finally able to get basic servo'd control working. Finally, I designed and ordered a PCB which I populated myself, with help from my other project, The Toaster Reflow Oven. With this board I was able to once again achieve basic servo'd motion, although I realized at this point you really need the resolution of direct mosfet control, and with a mcu programmed from scratch this would be much faster than using the Feather. In the future, I plan to modify this existing design to go back to using mosfets and give this one more go.