The
microcontroller itself cannot supply the adequate current to power a DC
motor; so, just like it happened with the stepper, I needed a driver.
As luck would have it, turns out it's quite simple to build a simple
driver for a DC motor that spins only in one direction: all I needed
was a diode, a NPN transistor and a resistor.
The
transistor base signal is provided by the microcontroller PCB, which is
powered by the computer itself, and VCC (+12 V) is provided by an
external power supply.
I built the driver on a protoboard to
test it and, after some failed attempts, I finally got the DC motor up
and running! You can check it out on this video:
So, the driver is working! Now, it's time to design a PCB for it.
This is the schematic I made on Eagle:
And this is the PCB design:
This is the actual .PNG I used as input to the Roland Mill MDX-40:
You can download all the files (Eagle schematic and PCB design, the
.PNG file and the .RML file that was generated by fabModules) here
(password abc123).
After milling the PCB, this is what I got:
Then, I proceeded to soldering the components:
And this is the final result:
This driver truly served its purpose, and functioned properly through all the stages of the Final Project development.
