Faz-Wrench - Five Nights at Freddy&#39;s

i2c / SPI character LCD backpack - STEMMA QT / Qwiic

Overhead video demo of an LCD backpack wired to a small square microcontroller. Display on LCD reads: "adafruit (heart symbol) 16x2 character LCDs"

Character LCDs are a fun and easy way to have your microcontroller project talk back to you. They are also common, and easy to get, available in tons of colors and sizes.

guides with product

$9.95

In Stock

Standard LCD 16x2 + extras

Character LCD with 16x2 characters, with header and potentiometer

Standard HD44780 LCDs are useful for creating standalone projects.16 characters wide, 2 rowsWhite text on blue backgroundConnection port is 0.1"...

$9.95

In Stock

Adafruit I2C Stemma QT Rotary Encoder Breakout with NeoPixel

Top view video of a hand turning the rotary encoder knobs on three PCBs. The NeoPixel LEDs on each PCB change color. The OLED display changes its readout data with each twisty-turn.

Rotary encoders are soooo much fun! Twist em this way, then twist them that way. Unlike potentiometers, they go all the way around and often have little detents for tactile feedback....

$5.95

In Stock

Mini Oval Speaker with Short Wires - 8 Ohm 1 Watt

Hear the good news! This wee speaker is a great addition to any audio project where you need 8 ohm impedance and 1W or less of power. We particularly like...

$1.95

In Stock

16mm Illuminated Pushbutton - Green Momentary

Angled shot of a green 16mm illuminated pushbutton.

A button is a button, and an LED is a LED, but this LED illuminated button is a lovely combination of both! It's a medium sized button, large enough to press easily but not too big...

$1.50

In Stock

1 x Resistors - 220 ohm

Resistors - 220 ohm

1 x NeoPixel LED Side Light Strip - Black 120 LED

NeoPixel LED Side Light Strip - Black 120 LED

1 x 4400mAh Lipo

Lithium Ion Battery Pack - 3.7V 4400mAh

Out of Stock

2 x RP-SMA Jack to SMA Plug RF Adapter

RP-SMA Jack to SMA Plug RF Adapter

Add 2 to Cart

2 x Antenna with RP-SMA

Antenna with RP-SMA

Add 2 to Cart

1 x SPDT Slide Switch

Breadboard-friendly SPDT Slide Switch

1 x Rotary Encoder + Extras

Rotary Encoder + Extras

1 x Red Momentary

16mm Red Momentary

1 x Molex PicoBlade Cables

1.25mm Pitch 2-pin Cable Matching Pair - 40cm long - Molex PicoBlade Compatible

3 x JST-XH Extension Cable

JST-XH Extension Cable - 2.5mm Pitch - 500mm long

Add 3 to Cart

1 x STEMMA Cable - 400mm long

STEMMA QT / Qwiic JST SH 4-Pin Cable - 400mm long

1 x STEMMA QT - 50mm Long

STEMMA QT / Qwiic JST SH 4-Pin Cable - 50mm Long

1 x Premium Plug Socket 'Extension' Jumper Wires

Premium Plug Socket 'Extension' Jumper Wires - 20 x 3"

Download the latest version of CircuitPython for this board via circuitpython.org

2 x M2x6mm Screws

M2x6mm Screws

18 x M2.5x6mm

M2.5x6mm

6 x M3x8 screws

M3x8 screws

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3D Printing

Parts List

STL files for 3D printing are oriented to print "as-is" on FDM style machines. Parts are designed to 3D print without any support material. Original design source may be downloaded using the links below.

Edit Design

Download STLs

Slice with Settings for PLA material

The parts were sliced using CURA using the slice settings below.

PLA filament 200c extruder
0.2 layer height
10% gyroid infill
60mm/s print speed
60c heated bed

Supports for Top Case

Support Overhang Angle: 50
Support Destiny: 6%
Enable Support Interface
Enable Support Roof
Support Z Distance: .21

Multi-Color Label

The Lightning Bolt label can be printed in multiple colors using the change filament technique. In CURA slicer, open the post processing plugin window by going to the top file menu:

Extensions > Post Processing > Modify GCode

Click, Add a script and choose Filament Change.

Enter 3 in the layer input box for the color change.

LEDs and cover

3D printed diffusers and decals are glued on to the top cover.

A separate plate is glued on the inside to isolate the NeoPixel LEDs to shine through the diffusers.

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CircuitPython

CircuitPython is a derivative of MicroPython designed to simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get prototyping by requiring no upfront desktop software downloads. Simply copy and edit files on the CIRCUITPY drive to iterate.

CircuitPython Quickstart

Follow this step-by-step to quickly get CircuitPython running on your board.

install_circuitpython_on_rp2040_RP2040_UF2_downloaded.jpg

Click the link above to download the latest CircuitPython UF2 file.

Save it wherever is convenient for you.

To enter the bootloader, hold down the BOOT/BOOTSEL button (highlighted in red above), and while continuing to hold it (don't let go!), press and release the reset button (highlighted in red or blue above). Continue to hold the BOOT/BOOTSEL button until the RPI-RP2 drive appears!

If the drive does not appear, release all the buttons, and then repeat the process above.

You can also start with your board unplugged from USB, press and hold the BOOTSEL button (highlighted in red above), continue to hold it while plugging it into USB, and wait for the drive to appear before releasing the button.

A lot of people end up using charge-only USB cables and it is very frustrating! Make sure you have a USB cable you know is good for data sync.

install_circuitpython_on_rp2040_RP2040_bootloader_drive.jpg

You will see a new disk drive appear called RPI-RP2.

Drag the adafruit_circuitpython_etc.uf2 file to RPI-RP2.

The RPI-RP2 drive will disappear and a new disk drive called CIRCUITPY will appear.

That's it, you're done! :)

Safe Mode

You want to edit your code.py or modify the files on your CIRCUITPY drive, but find that you can't. Perhaps your board has gotten into a state where CIRCUITPY is read-only. You may have turned off the CIRCUITPY drive altogether. Whatever the reason, safe mode can help.

Safe mode in CircuitPython does not run any user code on startup, and disables auto-reload. This means a few things. First, safe mode bypasses any code in boot.py (where you can set CIRCUITPY read-only or turn it off completely). Second, it does not run the code in code.py. And finally, it does not automatically soft-reload when data is written to the CIRCUITPY drive.

Therefore, whatever you may have done to put your board in a non-interactive state, safe mode gives you the opportunity to correct it without losing all of the data on the CIRCUITPY drive.

Entering Safe Mode

To enter safe mode when using CircuitPython, plug in your board or hit reset (highlighted in red above). Immediately after the board starts up or resets, it waits 1000ms. On some boards, the onboard status LED (highlighted in green above) will blink yellow during that time. If you press reset during that 1000ms, the board will start up in safe mode. It can be difficult to react to the yellow LED, so you may want to think of it simply as a slow double click of the reset button. (Remember, a fast double click of reset enters the bootloader.)

In Safe Mode

If you successfully enter safe mode on CircuitPython, the LED will intermittently blink yellow three times.

If you connect to the serial console, you'll find the following message.

Copy Text

Auto-reload is off.
Running in safe mode! Not running saved code.

CircuitPython is in safe mode because you pressed the reset button during boot. Press again to exit safe mode.

Press any key to enter the REPL. Use CTRL-D to reload.

Auto-reload is off.
Running in safe mode! Not running saved code.

CircuitPython is in safe mode because you pressed the reset button during boot. Press again to exit safe mode.

Press any key to enter the REPL. Use CTRL-D to reload.

You can now edit the contents of the CIRCUITPY drive. Remember, your code will not run until you press the reset button, or unplug and plug in your board, to get out of safe mode.

Flash Resetting UF2

If your board ever gets into a really weird state and CIRCUITPY doesn't show up as a disk drive after installing CircuitPython, try loading this 'nuke' UF2 to RPI-RP2. which will do a 'deep clean' on your Flash Memory. You will lose all the files on the board, but at least you'll be able to revive it! After loading this UF2, follow the steps above to re-install CircuitPython.

Download flash erasing "nuke" UF2

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Code

Once you've finished setting up your RP2040 Prop-Maker Feather with CircuitPython, you can access the code and necessary libraries by downloading the Project Bundle.

To do this, click on the Download Project Bundle button in the window below. It will download to your computer as a zipped folder.

Download Project Bundle

# SPDX-FileCopyrightText: Copyright (c) 2023 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import os
import random
import board
import audiocore
import audiobusio
import audiomixer
from digitalio import DigitalInOut, Direction
import neopixel
from adafruit_ticks import ticks_ms, ticks_add, ticks_diff
from adafruit_led_animation.animation.pulse import Pulse
from adafruit_led_animation.color import RED, GREEN
import adafruit_character_lcd.character_lcd_i2c as character_lcd
import adafruit_lis3dh
from adafruit_seesaw.seesaw import Seesaw
from adafruit_seesaw.rotaryio import IncrementalEncoder
import keypad

puzzle_time = 5 # seconds

lcd_columns = 16
lcd_rows = 2

# enable external power pin
# provides power to the external components
external_power = DigitalInOut(board.EXTERNAL_POWER)
external_power.direction = Direction.OUTPUT
external_power.value = True

i2c = board.I2C()

int1 = DigitalInOut(board.ACCELEROMETER_INTERRUPT)
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
lis3dh.range = adafruit_lis3dh.RANGE_2_G

ss_enc0 = Seesaw(i2c, addr=0x36)
enc0 = IncrementalEncoder(ss_enc0)

button = keypad.Keys((board.EXTERNAL_BUTTON, board.D13,), value_when_pressed=False, pull=True)

lcd = character_lcd.Character_LCD_I2C(i2c, lcd_columns, lcd_rows)
lcd.backlight = True

puzzle_msgs = ["UNLOCK\nDOOR", "DOOR\nUNLOCKED", "UNLOCKING"]

wavs = []
for filename in os.listdir('/faz_sounds'):
    if filename.lower().endswith('.wav') and not filename.startswith('.'):
        wavs.append("/faz_sounds/"+filename)
wavs.sort()
print(wavs)

audio = audiobusio.I2SOut(board.I2S_BIT_CLOCK, board.I2S_WORD_SELECT, board.I2S_DATA)
mixer = audiomixer.Mixer(voice_count=1, sample_rate=22050, channel_count=1,
                         bits_per_sample=16, samples_signed=True, buffer_size=32768)
volume = 0.5
mixer.voice[0].level = volume
audio.play(mixer)
wav_length = len(wavs) - 1

def open_audio(num):
    n = wavs[num]
    f = open(n, "rb")
    w = audiocore.WaveFile(f)
    return w

PIXEL_PIN = board.EXTERNAL_NEOPIXELS
BRIGHTNESS = 0.3
NUM_PIXELS = 8

PIXELS = neopixel.NeoPixel(PIXEL_PIN, NUM_PIXELS, auto_write=True)
pulse = Pulse(PIXELS, speed=0.001, color=RED, period=3)

puzzle_clock = ticks_ms()
puzzle_time = puzzle_time * 1000

puzzle = False
wave = open_audio(0)
pos0 = volume
last_pos0 = pos0
node_num = 0

def normalize(val, min_v, max_v):
    return max(min(max_v, val), min_v)

def puzzle_string(length):
    _string = ""
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    _string += "\n"
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    lcd.message = _string
    return _string

while True:
    event = button.events.get()
    if event and event.pressed:
        number = event.key_number
        if number == 0 and not puzzle:
            pulse.fill(GREEN)
            puzzle = True
            lcd.clear()
            lcd.message = puzzle_msgs[2]
            wave = open_audio(1)
            mixer.voice[0].play(wave)
            while mixer.playing:
                pass
            puzzle_clock = ticks_add(ticks_ms(), puzzle_time)
        if number == 1:
            lcd.clear()
            node_num = (node_num + 1) % 5
            print(node_num)

    if puzzle:
        x, y, z = [
            value / adafruit_lis3dh.STANDARD_GRAVITY for value in lis3dh.acceleration
            ]
        puzzle_string(lcd_columns*lcd_rows)
        if z > 0:
            wave = open_audio(2)
            print("playing up")
            pulse.fill(GREEN)
        else:
            wave = open_audio(3)
            print("playing down")
            pulse.fill(RED)
        mixer.voice[0].play(wave)
        while mixer.playing:
            puzzle_string(lcd_columns*lcd_rows)
            x, y, z = [
            value / adafruit_lis3dh.STANDARD_GRAVITY for value in lis3dh.acceleration
            ]
            if z > 0:
                pulse.fill(GREEN)
            else:
                pulse.fill(RED)
            if ticks_diff(ticks_ms(), puzzle_clock) >= puzzle_time:
                lcd.clear()
                puzzle = False
                lcd.message = puzzle_msgs[1]
                wave = open_audio(4)
                mixer.voice[0].play(wave)
                while mixer.playing:
                    pass
                print("puzzle done")
                wave = open_audio(0)
                lcd.clear()
                pulse.fill(RED)

    if not puzzle:
        pulse.animate()
        mixer.voice[0].play(wave, loop=True)
        if node_num > 3:
            lcd.message = "SECURITY\nBREACHED"
        else:
            lcd.message = f"DEACTIVATED:\n{node_num} of 4"
        pos0 = -enc0.position
        if pos0 != last_pos0:
            if pos0 > last_pos0:
                volume = volume + 0.1
            else:
                volume = volume - 0.1
            volume = normalize(volume, 0.0, 1.0)
            mixer.voice[0].level = volume
            last_pos0 = pos0

# SPDX-FileCopyrightText: Copyright (c) 2023 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

import os
import random
import board
import audiocore
import audiobusio
import audiomixer
from digitalio import DigitalInOut, Direction
import neopixel
from adafruit_ticks import ticks_ms, ticks_add, ticks_diff
from adafruit_led_animation.animation.pulse import Pulse
from adafruit_led_animation.color import RED, GREEN
import adafruit_character_lcd.character_lcd_i2c as character_lcd
import adafruit_lis3dh
from adafruit_seesaw.seesaw import Seesaw
from adafruit_seesaw.rotaryio import IncrementalEncoder
import keypad

puzzle_time = 5 # seconds

lcd_columns = 16
lcd_rows = 2

# enable external power pin
# provides power to the external components
external_power = DigitalInOut(board.EXTERNAL_POWER)
external_power.direction = Direction.OUTPUT
external_power.value = True

i2c = board.I2C()

int1 = DigitalInOut(board.ACCELEROMETER_INTERRUPT)
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
lis3dh.range = adafruit_lis3dh.RANGE_2_G

ss_enc0 = Seesaw(i2c, addr=0x36)
enc0 = IncrementalEncoder(ss_enc0)

button = keypad.Keys((board.EXTERNAL_BUTTON, board.D13,), value_when_pressed=False, pull=True)

lcd = character_lcd.Character_LCD_I2C(i2c, lcd_columns, lcd_rows)
lcd.backlight = True

puzzle_msgs = ["UNLOCK\nDOOR", "DOOR\nUNLOCKED", "UNLOCKING"]

wavs = []
for filename in os.listdir('/faz_sounds'):
    if filename.lower().endswith('.wav') and not filename.startswith('.'):
        wavs.append("/faz_sounds/"+filename)
wavs.sort()
print(wavs)

audio = audiobusio.I2SOut(board.I2S_BIT_CLOCK, board.I2S_WORD_SELECT, board.I2S_DATA)
mixer = audiomixer.Mixer(voice_count=1, sample_rate=22050, channel_count=1,
                         bits_per_sample=16, samples_signed=True, buffer_size=32768)
volume = 0.5
mixer.voice[0].level = volume
audio.play(mixer)
wav_length = len(wavs) - 1

def open_audio(num):
    n = wavs[num]
    f = open(n, "rb")
    w = audiocore.WaveFile(f)
    return w

PIXEL_PIN = board.EXTERNAL_NEOPIXELS
BRIGHTNESS = 0.3
NUM_PIXELS = 8

PIXELS = neopixel.NeoPixel(PIXEL_PIN, NUM_PIXELS, auto_write=True)
pulse = Pulse(PIXELS, speed=0.001, color=RED, period=3)

puzzle_clock = ticks_ms()
puzzle_time = puzzle_time * 1000

puzzle = False
wave = open_audio(0)
pos0 = volume
last_pos0 = pos0
node_num = 0

def normalize(val, min_v, max_v):
    return max(min(max_v, val), min_v)

def puzzle_string(length):
    _string = ""
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    _string += "\n"
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    lcd.message = _string
    return _string

while True:
    event = button.events.get()
    if event and event.pressed:
        number = event.key_number
        if number == 0 and not puzzle:
            pulse.fill(GREEN)
            puzzle = True
            lcd.clear()
            lcd.message = puzzle_msgs[2]
            wave = open_audio(1)
            mixer.voice[0].play(wave)
            while mixer.playing:
                pass
            puzzle_clock = ticks_add(ticks_ms(), puzzle_time)
        if number == 1:
            lcd.clear()
            node_num = (node_num + 1) % 5
            print(node_num)

    if puzzle:
        x, y, z = [
            value / adafruit_lis3dh.STANDARD_GRAVITY for value in lis3dh.acceleration
            ]
        puzzle_string(lcd_columns*lcd_rows)
        if z > 0:
            wave = open_audio(2)
            print("playing up")
            pulse.fill(GREEN)
        else:
            wave = open_audio(3)
            print("playing down")
            pulse.fill(RED)
        mixer.voice[0].play(wave)
        while mixer.playing:
            puzzle_string(lcd_columns*lcd_rows)
            x, y, z = [
            value / adafruit_lis3dh.STANDARD_GRAVITY for value in lis3dh.acceleration
            ]
            if z > 0:
                pulse.fill(GREEN)
            else:
                pulse.fill(RED)
            if ticks_diff(ticks_ms(), puzzle_clock) >= puzzle_time:
                lcd.clear()
                puzzle = False
                lcd.message = puzzle_msgs[1]
                wave = open_audio(4)
                mixer.voice[0].play(wave)
                while mixer.playing:
                    pass
                print("puzzle done")
                wave = open_audio(0)
                lcd.clear()
                pulse.fill(RED)

    if not puzzle:
        pulse.animate()
        mixer.voice[0].play(wave, loop=True)
        if node_num > 3:
            lcd.message = "SECURITY\nBREACHED"
        else:
            lcd.message = f"DEACTIVATED:\n{node_num} of 4"
        pos0 = -enc0.position
        if pos0 != last_pos0:
            if pos0 > last_pos0:
                volume = volume + 0.1
            else:
                volume = volume - 0.1
            volume = normalize(volume, 0.0, 1.0)
            mixer.voice[0].level = volume
            last_pos0 = pos0

Upload the Code and Libraries to the RP2040 Prop-Maker Feather

After downloading the Project Bundle, plug your RP2040 Prop-Maker Feather into the computer's USB port with a known good USB data+power cable. You should see a new flash drive appear in the computer's File Explorer or Finder (depending on your operating system) called CIRCUITPY. Unzip the folder and copy the following items to the RP2040 Prop-Maker Feather's CIRCUITPY drive.

lib folder
faz_sounds folder
code.py

Your RP2040 Prop-Maker Feather CIRCUITPY drive should look like this after copying the lib folder, faz_sounds folder and the code.py file.

How the CircuitPython Code Works

The code begins by instantiating the LCD screen, accelerometer, and encoder over I2C. The two buttons are added to a keypad object.

# enable external power pin
# provides power to the external components
external_power = DigitalInOut(board.EXTERNAL_POWER)
external_power.direction = Direction.OUTPUT
external_power.value = True

i2c = board.I2C()

int1 = DigitalInOut(board.ACCELEROMETER_INTERRUPT)
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
lis3dh.range = adafruit_lis3dh.RANGE_2_G

ss_enc0 = Seesaw(i2c, addr=0x36)
enc0 = IncrementalEncoder(ss_enc0)

button = keypad.Keys((board.EXTERNAL_BUTTON, board.D13,), value_when_pressed=False, pull=True)

lcd = character_lcd.Character_LCD_I2C(i2c, lcd_columns, lcd_rows)
lcd.backlight = True

# enable external power pin
# provides power to the external components
external_power = DigitalInOut(board.EXTERNAL_POWER)
external_power.direction = Direction.OUTPUT
external_power.value = True

i2c = board.I2C()

int1 = DigitalInOut(board.ACCELEROMETER_INTERRUPT)
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
lis3dh.range = adafruit_lis3dh.RANGE_2_G

ss_enc0 = Seesaw(i2c, addr=0x36)
enc0 = IncrementalEncoder(ss_enc0)

button = keypad.Keys((board.EXTERNAL_BUTTON, board.D13,), value_when_pressed=False, pull=True)

lcd = character_lcd.Character_LCD_I2C(i2c, lcd_columns, lcd_rows)
lcd.backlight = True

Audio

The sound effects WAV files are imported from the faz_sounds folder. Audio is output to the I2S amp on the Feather thru a Mixer object. The open_audio() function is used throughout the loop to open and play the sound effects.

wavs = []
for filename in os.listdir('/faz_sounds'):
    if filename.lower().endswith('.wav') and not filename.startswith('.'):
        wavs.append("/faz_sounds/"+filename)
wavs.sort()
print(wavs)

audio = audiobusio.I2SOut(board.I2S_BIT_CLOCK, board.I2S_WORD_SELECT, board.I2S_DATA)
mixer = audiomixer.Mixer(voice_count=1, sample_rate=22050, channel_count=1,
                         bits_per_sample=16, samples_signed=True, buffer_size=32768)
volume = 0.5
mixer.voice[0].level = volume
audio.play(mixer)
wav_length = len(wavs) - 1

def open_audio(num):
    n = wavs[num]
    f = open(n, "rb")
    w = audiocore.WaveFile(f)
    return w

wavs = []
for filename in os.listdir('/faz_sounds'):
    if filename.lower().endswith('.wav') and not filename.startswith('.'):
        wavs.append("/faz_sounds/"+filename)
wavs.sort()
print(wavs)

audio = audiobusio.I2SOut(board.I2S_BIT_CLOCK, board.I2S_WORD_SELECT, board.I2S_DATA)
mixer = audiomixer.Mixer(voice_count=1, sample_rate=22050, channel_count=1,
                         bits_per_sample=16, samples_signed=True, buffer_size=32768)
volume = 0.5
mixer.voice[0].level = volume
audio.play(mixer)
wav_length = len(wavs) - 1

def open_audio(num):
    n = wavs[num]
    f = open(n, "rb")
    w = audiocore.WaveFile(f)
    return w

NeoPixels

The NeoPixels are connected to the EXTERNAL_NEOPIXELS pin. The pulse animation is used.

PIXEL_PIN = board.EXTERNAL_NEOPIXELS
BRIGHTNESS = 0.3
NUM_PIXELS = 8

PIXELS = neopixel.NeoPixel(PIXEL_PIN, NUM_PIXELS, auto_write=True)
pulse = Pulse(PIXELS, speed=0.001, color=RED, period=3)

PIXEL_PIN = board.EXTERNAL_NEOPIXELS
BRIGHTNESS = 0.3
NUM_PIXELS = 8

PIXELS = neopixel.NeoPixel(PIXEL_PIN, NUM_PIXELS, auto_write=True)
pulse = Pulse(PIXELS, speed=0.001, color=RED, period=3)

Generate a Puzzle

The puzzle_string() function generates a random series of letters and numbers to fill the LCD when the Faz Wrench is in puzzle mode.

def puzzle_string(length):
    _string = ""
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    _string += "\n"
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    lcd.message = _string
    return _string

def puzzle_string(length):
    _string = ""
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    _string += "\n"
    for _ in range(length/2):
        b = random.randint(0, 1)
        if b == 0:
            r = chr(random.randint(ord('A'), ord('Z')))
        else:
            r = str(random.randint(0, 9))
        _string += r
    lcd.message = _string
    return _string

Keypad Events

The loop is checking for two things: a keypad event and if puzzle mode is active. The keypad events are tied to a key_number. If key_number 0 is pressed, then puzzle mode is enacted. If key_number 1 is pressed, then the value of node_num is increased by 1. This updates text on the LCD.

event = button.events.get()
    if event and event.pressed:
        number = event.key_number
        if number == 0 and not puzzle:
            pulse.fill(GREEN)
            puzzle = True
            lcd.clear()
            lcd.message = puzzle_msgs[2]
            wave = open_audio(1)
            mixer.voice[0].play(wave)
            while mixer.playing:
                pass
            puzzle_clock = ticks_add(ticks_ms(), puzzle_time)
        if number == 1:
            lcd.clear()
            node_num = (node_num + 1) % 5
            print(node_num)

event = button.events.get()
    if event and event.pressed:
        number = event.key_number
        if number == 0 and not puzzle:
            pulse.fill(GREEN)
            puzzle = True
            lcd.clear()
            lcd.message = puzzle_msgs[2]
            wave = open_audio(1)
            mixer.voice[0].play(wave)
            while mixer.playing:
                pass
            puzzle_clock = ticks_add(ticks_ms(), puzzle_time)
        if number == 1:
            lcd.clear()
            node_num = (node_num + 1) % 5
            print(node_num)

Default Mode

If puzzle is False, then the Faz Wrench is in its default mode. The LCD displays the text "DEACTIVATED: 0 OF 4", with 0 being the value of node_num. node_num increases with a button press. When node_num is greater than 3, the text "SECURITY BREACHED" is displayed. The rotary encoder is used in this mode to control the volume of the sound effects.

if not puzzle:
        pulse.animate()
        mixer.voice[0].play(wave, loop=True)
        if node_num > 3:
            lcd.message = "SECURITY\nBREACHED"
        else:
            lcd.message = f"DEACTIVATED:\n{node_num} of 4"
        pos0 = -enc0.position
        if pos0 != last_pos0:
            if pos0 > last_pos0:
                volume = volume + 0.1
            else:
                volume = volume - 0.1
            volume = normalize(volume, 0.0, 1.0)
            mixer.voice[0].level = volume
            last_pos0 = pos0

if not puzzle:
        pulse.animate()
        mixer.voice[0].play(wave, loop=True)
        if node_num > 3:
            lcd.message = "SECURITY\nBREACHED"
        else:
            lcd.message = f"DEACTIVATED:\n{node_num} of 4"
        pos0 = -enc0.position
        if pos0 != last_pos0:
            if pos0 > last_pos0:
                volume = volume + 0.1
            else:
                volume = volume - 0.1
            volume = normalize(volume, 0.0, 1.0)
            mixer.voice[0].level = volume
            last_pos0 = pos0

Puzzle Mode

In puzzle mode, the sound effect and NeoPixel color changes based on the orientation of the accelerometer. The LCD text displays random letters and numbers that are generated with the puzzle_string() function.