hheisig51/VigilantWaddle

Just Henry Heisig's CircuitPython repo

Engineering III Notebook - Circuit Python

Table of Contents

• Table of Contents
• Hello_CircuitPython
• CircuitPython_Servo

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Hello_CircuitPython

Description & Code

Hello! In this, an LED on an Arduino (via Python) fades & flashes in a rainbow-ish pattern.

# Written by Henry Heisig, 09.01.21
import board
import neopixel
import time

x = 50
y = 50
z = 50
dot = neopixel.NeoPixel(board.NEOPIXEL, 1)

dot.brightness = .1

The variables set up will correspond to the different RGB channels on the LED. The brightness of the LED is also lowered

Variable	Color Channel
X	R ed
Y	G reen
Z	B lue

while True:
    dot.fill((x, y, z))
    time.sleep(.25)
    x = x + 1
    if x >= 255:
        x = 50

    y = y + 5
    if y >= 255:
        y = 50

For example, every time this loops, y gets 5 added to it, and then it checks if z is at or above 255 (the max value the channel can be). If it is, it gets knocked back down to 50, to then start the process over again.

    z = z + 10
    if z >= 255:
        z = 50

    print((x, y, z))

Evidence

Code .py file
Youtube playlist of videos

NeopixelCode.mp4

NeopixelVideo.mp4

Wiring

In this example, no wiring is needed. The neopixel on the Adafruit Arduino Metro was used.

Reflection

1. In the code above, the dot.brightness = .1 is important for preventing any LED burnout, alongside enabling the LED to better produce the colors.
2. At the end of the code above, the print((x, y, z)) is part of a bigger thing to remember; printing to the serial monitor is highly important in every project. Don't overwhelmn it, but use it as a tool.

This assignment is a basis for learning more about CircuitPython. There's only thing to plug in is the board. The hardest part was actually figuring out the code to change the channels at different rates. Python is such an able language, that finding the exact resource you need is hard. Search engines (Ecosia, DuckDuckGo, Google, etc.) are all good tools to be able to peruse the web.

Also, ASK! PEOPLE! QUESTIONS! If you don't, the person next to you is 10 steps ahead, it s because they asked the person who's ahead by 11. If you manage to find something that nobody has documented, please document it yourself.

CircuitPython_Servo

Description & Code

So, our objective today is to properly wire up a servo, and then use two wires, via touch, to control the servo.

First step: wire the board and servo as shown below. If you want to, you can change the analog pins around, just make sure you change it in the code also.

# Written by Henry Heisig, 09.15.21
import time
import board
import pwmio
import servo
import touchio

pwmio, servo, and touchio are new this go-around, so make sure you grab servo.mpy and put it into your lib folder.

(Here you can grab a CircuitPython Library package. In /lib/adafruit_motor you'll find servo.mpy)

pwm = pwmio.PWMOut(board.A2, duty_cycle=2 ** 15, frequency=50)

my_servo = servo.Servo(pwm)

touch = touchio.TouchIn(board.A0)
tauch = touchio.TouchIn(board.A4)

• The pwm = sets up the actual frequency the board will output that (via the analog pins) to the servo.
• my_servo makes sure we can actually send values to the servo, and have them be correct.
• The touch = and tauch = setup the input from the two pin A0 and A4.

angle = 0
while True:
    if touch.value:
        print("Touched A0")
        my_servo.angle = angle
        if angle < 180:
            angle = angle + 5
        if angle >= 180:
            angle = 180
        print(angle)

• angle = 0 resets the value before any loop starts, just to prevent errors.
• if touch.value: carries out what's contained if something touches A0 (like it was set up above).
• my_servo.angle = angle set's the actual servo angle based off of the value of angle.
• The next series of statements, everytime this runs;
  • increase the angle by 5 degrees if it's less than 180.
  • if 180 or greater, keeps it at 180, to prevent any errors from sending too large of a number to the servo.
  • prints the value of angle, for use with the serial monitor.

    if tauch.value:
        print("Tauched A4")
        my_servo.angle = angle
        if angle > 0:
            angle = angle - 5
        if angle <= 0:
            angle = 0
        print(angle)
    time.sleep(0.05)

• Very similar thing as description above, just for A4 instead (see how it's tauch instead of touch?).
• Just goes down by 5 degree increments to 0.
• There's also the time.sleep function that calls at the end of the whole while True: loop.

Evidence

Code .py file
Youtube playlist of videos

ServoCode.mp4

ServoExample.mp4

Wiring

Wire color	Pin on board	Purpose
Red	5V	Power on Servo
Black	GND	Ground on Servo
Yellow	A2	Signal on Servo
Blue	A0	Capacitive Touch
Grey	A4	Capacitive Touch

Reflection

This Adafruit tutorial can give the very essential building blocks for to start the whole assignment.

As the adafruit was linked above, and as classmates may be linked in the future, there's no need to invent the wheel twice. Steal, borrow, copy, take, link, anything. Give credit where credit is due, and all is well.

Also, writing out the math can help in making it work code wise. Similar to the domain, range, and intervals in a function.

Special Thanks

Thank you to Mr. Helmstetter and Mr. Dierolf at Charlottesville High School for being very helpful

Thank you to Github, VSCode, Mu, OBS, FFmpeg, and QWinFF for being good software resources.

And of course - shoutout to all my classmates, and my lab partner of two years; Shrey P.