Prep your wrist for the apocalypse! Build your own small form-factor, Fallout-inspired Pip-Boy with Feather RP2040 and CircuitPython.

You can make this prop wrist-computer for cosplay, or for general stylishness all the time. Swap graphic screens on the beautiful round rectangle IPS TFT display with the directional buttons, move the cursor with the joystick, look rad.

The demo code is a simple slide-show with navigation controls, but the platform can be used to code your own unique device behavior.


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2 x Short Feather Header Pins
12-pin and 16-pin set
1 x Short Feather Header Sockets
12-pin and 16-pin set

Watch Strap

I used a 22mm wide nylon band, similar to this one.

Display Circuit

Here's what the circuit looks like when directly wired to the Feather. Don't solder this together just yet, we'll use the Feather Tripler as shown below for the build. 

An earlier version of this guide had incorrect wiring, the author humbly apologizes for the errors.

This view shows the same wiring (minus the enable switch) but with the screen to the left of the Feather as it will be on the Tripler.


Here's an initial layout to determine parts placement on the FeatherWing Tripler.


This diagram shows the display wired to the Feather via the Tripler. This illustration has the display off to the side for clarity. On the real board you'll use the header to connect the display to the board with this wiring in place.

Here's what it looks like with the display in place but the wiring visible x-ray style.

Non-xray version. Note that the display will not overlap the Feather in the final board, thanks to an angled stacking header.

Feather Soldering

A compact way to attach the Feather to the board, while allowing the Joy FeatherWing to mount on top is to solder extra-long pins directly through the Feather to the Tripler as shown here.

Then, solder the socket headers to the Joy FeatherWing.

Screen Socket Soldering

Use a tall stacking header to create a pluggable socket for the display.

This will set the screen at a good height for the build, and you can bend the long headers to use as connection points for the wires on the FeatherWing Tripler.

Follow the wiring in the photo as well as the Fritzing diagrams above.

Solder in the slide switch as well and wire it to the ground and Enable pins of the Feather.


Use a length of double-stick foam tape to secure the battery to the FeatherWing. This will keep it from rattling around inside your Pip-Boy.

Assemble the Pip-Boy Components

Plug in the Joy FeatherWing, and the display.

It's now ready for coding and case assembly.

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.

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 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.

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 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 (where you can set CIRCUITPY read-only or turn it off completely). Second, it does not run the code in 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 in CircuitPython 6.x

This section explains entering safe mode on CircuitPython 6.x.

To enter safe mode when using CircuitPython 6.x, plug in your board or hit reset (highlighted in red above). Immediately after the board starts up or resets, it waits 700ms. On some boards, the onboard status LED (highlighted in green above) will turn solid yellow during this time. If you press reset during that 700ms, 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.)

Entering Safe Mode in CircuitPython 7.x

This section explains entering safe mode on CircuitPython 7.x.

To enter safe mode when using CircuitPython 7.x, 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

Once you've entered safe mode successfully in CircuitPython 6.x, the LED will pulse yellow.

If you successfully enter safe mode on CircuitPython 7.x, the LED will intermittently blink yellow three times.

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

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 doesn't even show up as a disk drive when installing CircuitPython, try loading this 'nuke' UF2 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.

Text Editor

Adafruit recommends using the Mu editor for editing your CircuitPython code. You can get more info in this guide.

Alternatively, you can use any text editor that saves simple text files.

Download the Project Bundle

Your project will use a specific set of CircuitPython libraries and the file, along with a folder full of image files. To get everything you need, click on the Download Project Bundle link below, and uncompress the .zip file.

Drag the contents of the uncompressed bundle directory onto your Feather board's CIRCUITPY drive, replacing any existing files or directories with the same names, and adding any new ones that are necessary.

# SPDX-FileCopyrightText: 2021 john park for Adafruit Industries
# SPDX-License-Identifier: MIT
import time
import board
from adafruit_simplemath import map_range
import displayio
from adafruit_seesaw.seesaw import Seesaw
import adafruit_imageload
from adafruit_st7789 import ST7789


i2c_bus = board.I2C()
ss = Seesaw(i2c_bus)

spi = board.SPI()  # setup for display over SPI
tft_cs = board.D5
tft_dc = board.D6
display_bus = displayio.FourWire(
    spi, command=tft_dc, chip_select=tft_cs, reset=board.D9

display = ST7789(display_bus, width=280, height=240, rowstart=20, rotation=270)

screen = displayio.Group()  # Create a Group to hold content  # Add it to the Display

# display image
image = displayio.OnDiskBitmap("/img/bootpip0.bmp")
palette = image.pixel_shader
background = displayio.TileGrid(image, pixel_shader=palette)

# load cursor on top
cursor_on = True
if cursor_on:
    image, palette = adafruit_imageload.load("/img/cursor_green.bmp")
    cursor = displayio.TileGrid(image, pixel_shader=palette)

    cursor.x = 0  # hide cursor during bootup
    cursor.y = 0

boot_file_names = [

screenmap = {
    (0): (
    (1): ("/img/invpip0.bmp", "/img/invpip1.bmp"),
    (2): ("/img/datapip0.bmp", "/img/datapip1.bmp", "/img/datapip2.bmp"),
    (3): ("/img/mappip0.bmp", "/img/mappip1.bmp", "/img/mappip2.bmp"),
    (4): ("/img/radiopip0.bmp", "/img/radiopip1.bmp"),
    (5): ("/img/holopip0.bmp", "/img/holopip1.bmp"),

BUTTON_UP = 6  # A is UP
BUTTON_SEL = 14  # SEL button is unused
button_mask = (
    (1 << BUTTON_UP)
    | (1 << BUTTON_RIGHT)
    | (1 << BUTTON_DOWN)
    | (1 << BUTTON_LEFT)
    | (1 << BUTTON_SEL)

ss.pin_mode_bulk(button_mask, ss.INPUT_PULLUP)

tab_number = 0
sub_number = 0

def image_switch(direction):  # advance or go back through image list
    # pylint: disable=global-statement
    global tab_number
    # pylint: disable=global-statement
    global sub_number
    # pylint: disable=global-statement
    global image
    # pylint: disable=global-statement
    global palette
    if direction == 0:  # right
        tab_number = (tab_number + 1) % len(screenmap)
    if direction == 1:  # left
        tab_number = (tab_number - 1) % len(screenmap)
    if direction == 2:  # down
        sub_number = (sub_number + 1) % len((screenmap[tab_number]))
    if direction == 3:  # up
        sub_number = (sub_number - 1) % len((screenmap[tab_number]))

    image = displayio.OnDiskBitmap(screenmap[tab_number][sub_number])
    palette = image.pixel_shader
    screen[0] = displayio.TileGrid(image, pixel_shader=palette)

last_joy_x = 0
last_joy_y = 0

#  bootup images
for i in range(len(boot_file_names)):
    image = displayio.OnDiskBitmap(boot_file_names[i])
    palette = image.pixel_shader
    screen[0] = displayio.TileGrid(image, pixel_shader=palette)

while True:
    joy_x = ss.analog_read(2)
    joy_y = ss.analog_read(3)
    if (abs(joy_x - last_joy_x) > 3) or (abs(joy_y - last_joy_y) > 3):
        if cursor_on:
            cursor.x = int(map_range(joy_x, 10, 1023, 0, 264))
            cursor.y = int(map_range(joy_y, 10, 1023, 224, 0))
        last_joy_x = joy_x
        last_joy_y = joy_y

    buttons = ss.digital_read_bulk(button_mask)

    if not buttons & (1 << BUTTON_UP):

    if not buttons & (1 << BUTTON_RIGHT):
        sub_number = 0  # go back to top level screen of tab grouping

    if not buttons & (1 << BUTTON_DOWN):

    if not buttons & (1 << BUTTON_LEFT):
        sub_number = 0

    if not buttons & (1 << BUTTON_SEL):
        print("unused select button")

Use the Pip-Boy

While this platform can be used to code your own unique behavior, the project example is a simple slide-show with input controls.

When the Pip-Boy 2040 boots up it will run through a series of images, then pause. You can use the left and right buttons to got between menus, and the up and down buttons to show the sub-menu screens.

The joystick will move the cursor around the screen.

You can build a 3D printed, wrist-mounted case for your Pip-Boy 2040. A nylon watch strap will allow you to adjust it for a perfect fit -- or you can use velcro strips to secure it to a costume jacket or rad cyber armor.

Print the Case

Print the three model files (linked above) at 0.2mm layer height and 18% infill.

Threaded Inserts

For case section assembly, use M4 x 30mm socket-head screws, and M4 x 0.7mm thread brass heat-set inserts.

For more info on using heat-set threaded inserts, see this guide.

Using your soldering iron, carefully heat and sink the four inserts into the model as shown.

Case Top

Secure the Joy FeatherWing and the Display to the case top using eight M2.5 x 10mm screws and nuts.


Align the boards and press the header pins into the sockets.

Then, fit the board into the middle section, making sure to line up the USB-C port.


Flip the base so the curved face is down (this is contoured for your arm), with the flat side facing the board.

Use the M4 screws to assemble the three sections, screwing them into the threaded inserts.

Extra Inserts

You can add four inserts on top of the excess screw length for that post-apocalyptic atom-punk look!


Add your watch strap and you're ready to wear the Pip-Boy 2040.

Flip the slide switch to power it on.

This guide was first published on Dec 14, 2021. It was last updated on 2021-12-14 22:10:37 -0500.