Week 10 Output Devices

Link to Group Site

This week, I decided to use a DC motor as my output device. In my final project, I will have multiple fans driven by motors.

My board from input week has a DC motor, which fits the requirements for this week. I will still include the process of creating the board.

I created this schematic in KiCad. The upper two pin connector is for the motor. The lower two pin connector is for the power supply. The 3 pin connector is for a mosfet.

These are the footprints I used. The LED footprint is for the diode. The diode prevents EMF, which can damage my microcontroller.

I imported all of the footprints into the pcb editor, arranged them, then sketched the traces. I gave my board larger traces because in the past, some of my traces ripped away during the soldering process. I made my board compact to save on material cost.

After I designed my board, I went to file, fabrication outputs, then gerbers. These are the settings I used to generate my gerbers. I only needed the front copper gerbers and the edge cut gerbers, but ended up generating gerbers for more because I forgot to uncheck those boxes. Gerbers only generate the traces, so I needed to generate the drill files for the through holes.

I went to the same place to generate the drill files. File, fabrication outputs, then drill files. These are the settings I used to generate the drill files.

**Click Here to download my KiCad file

(The Gerbers are in the KiCad file, the .drl file is not)

**Click Here to download the .drl file

Makera Cam Settings

I used these settings above in Makera CAM for my traces. This toolpath goes with the traces gerbers.

I used these settings above in Makera CAM for my outline. This toolpath goes with the outline gerbers.

I used these settings in Makera CAM for my through holes. This toolpath goes with the .drl file.

After I created the toolpaths, I generated the gcode.

Click Here to Download the GCode

I milled the board again this week, because last week, I had some issues with the diode.

Milling, Soldering, and Populating the Board

I put a copper stock, like this, the bed, with double sided tape under it. I then finally clamped it down.

This is the board after soldering and populating. As you can see, My soldering skills were much better this week compared to last week.

Code

I used the same code I used during week 9.

from machine import Pin, ADC, PWM
import time

# Potentiometer on A0 (GPIO 26)
pot = ADC(Pin(26))

# TIP120 base driven from D2 (GPIO 28)
motor = PWM(Pin(28))
motor.freq(2000)  # TIP120 works better at higher PWM frequency

while True:
    val = pot.read_u16()
    motor.duty_u16(val)
    time.sleep(0.01)

Testing the Output Device

As you can see, the motor spins. Its speed is able to be increased and decreased by PWM.

Reflection

This week wasn't to difficult. I put this week off a while because of machine week. When I started the week, I realized my board from week 9 met the requirements. I still milled the board again, but the process was very smooth because I had done it before. The group work was also very easy.