NeoPixel LED Heart Necklace - Adafruit Industries · BLE with ItsyBitsy You can change the colors of the LEDs using the Adafruit BLE Connect app for iOS or Android. You can also trigger

NeoPixel LED Heart NecklaceCreated by Ruiz Brothers

Last updated on 2020-05-05 02:35:07 PM EDT

Overview

NeoPixel Heart

In this project we’re building an LED heart with NeoPixels. This uses Black LED acrylic to diffuse the NeoPixels inside a3D printed case. The heart is made from pieces of strips that are daisy chained to create a custom matrix.

3D Printed CaseThe ItsyBitsy nRF52840 and 500mah lipo battery are

housed in a separate 3D printed case. With a lipo

backpack, you can recharge the battery over USB. We

think this case will work nicely for your next wearable

project. A button lets you trigger a reset, so you can

easily update the firmware.

© Adafruit Industries https://learn.adafruit.com/neopixel-led-heart-necklace Page 4 of 32

https://learn.adafruit.com/assets/88200

https://www.adafruit.com/product/4481







BLE with ItsyBitsyYou can change the colors of the LEDs using the

Adafruit BLE Connect app for iOS or Android. You can

also trigger LED animations like the classic Paint your

Dragon rainbow swirl. With the ItsyBitsy nRF52840, you

can easily add BLE to your wearable projects.

Parts List

List of parts used to build this project.

Adafruit ItsyBitsy nRF52840 (https://adafru.it/IsE)

Mini Skinny NeoPixel Strip (https://adafru.it/lXb)

Trinket/ItsyBitsy Lipo

Backpack (https://adafru.it/e0w)

500mAh battery (https://adafru.it/drL)

Slide Switch (https://adafru.it/drN)

10-wire ribbon cable (https://adafru.it/CJj)

Fully reversible USB cable (https://adafru.it/GWF)

Black LED Acrylic (https://adafru.it/IVf)

Adafruit ItsyBitsy nRF52840 Express - Bluetooth LE

$17.95IN STOCK

Add To Cart

Your browser does not support the video tag. Adafruit Mini Skinny NeoPixel Digital RGB LED Strip - 144LED/m











https://www.tapplastics.com/product/plastics/cut_to_size_plastic/black_led_sheet/668




$64.95IN STOCK

Add To Cart

Adafruit LiIon/LiPoly Backpack Add-On for ProTrinket/ItsyBitsy

$4.95IN STOCK

Add To Cart

Lithium Ion Polymer Battery - 3.7v 500mAh

$7.95IN STOCK

Add To Cart

Breadboard-friendly SPDT Slide Switch

OUT OF STOCK

Out Of Stock









1 x Black LED Acrylic100mm x 100mm - 1/8in thickness

BUY NOW

1 x 1/8in Flat End MillSingle Flute Upcut

BUY NOW

1 x Bantam Tools CNCDesktop CNC Milling Machine

BUY NOW

Silicone Cover Stranded-Core Ribbon Cable - 10 Wire 1Meter Long

$3.95IN STOCK

Add To Cart

Fully Reversible Pink/Purple USB A to micro B Cable - 1mlong

$3.95IN STOCK

Add To Cart








https://www.inventables.com/technologies/solid-carbide-single-flute-upcut-end-mill


https://www.bantamtools.com/


Inspirational Source:This project was inspired by Charlyn

Gonda (https://adafru.it/IVD)'s Ring project. Check it out

on her website:

https://charlyn.codes/magic-acrylic-stays-opaque-until-

light-shines-through/ (https://adafru.it/IVE)



https://twitter.com/chardane

https://charlyn.codes/magic-acrylic-stays-opaque-until-light-shines-through/

3D Printing

3D Printed PartsSTL files for 3D printing are oriented to print "as-is" on

FDM style machines. Original design source may be

downloaded using the links below.

heart-case.stl

itsy-reset.stl

itsy-cover.stl

itsy-case.stl

https://adafru.it/IWa

https://adafru.it/IWa

https://adafru.it/IWb

https://adafru.it/IWb

CAD ExplodeThe ItsyBitsy and Lipo backpack snap fit into the case.

The ItsyBitsy board is secured with mounting taps. The

slide switch is inserted into a little holder built into the

case. A small button fits over the reset button. A

500mAh lipo battery is placed over the components.

The cover is fitted over the case and snap fits.



https://www.thingiverse.com/thing:4155153

https://www.prusaprinters.org/prints/21553-neopixel-led-heart-necklace


Slicing PartsNo supports are required. Slice with setting for PLA

material.

The parts were sliced using CURA using the slice

settings below.

PLA filament 220c extruder

0.2 layer height

10% gyroid infill

60mm/s print speed

60c heated bed

Design Source FilesThe project assembly was designed in Fusion 360. This

can be downloaded in different formats like STEP, STL

and more. Electronic components like Adafruit's board,

displays, connectors and more can be downloaded from

the Adafruit CAD parts GitHub

Repo (https://adafru.it/AW8).




https://github.com/adafruit/Adafruit_CAD_Parts

Circuit Diagram

The diagram below provides a visual reference for wiring of the components. This diagram was created using thesoftware package Fritzing (https://adafru.it/oEP).

Adafruit Library for Fritzing

Use Adafruit's Fritzing parts library to create circuit diagrams for your projects. Download the library or just grabindividual parts. Get the library and parts from GitHub - Adafruit Fritzing Parts (https://adafru.it/AYZ).

Wired Connections

The ItsyBitsy nRF52840 is powered by 500mAh battery via the Lipo Backpack. This allows the USB port from theItsyBitsy nRF52840 to charge the 500mAh battery. A slide switch is connected to the two switch pin on the LipoBackpack.

BAT from Lipo Backpack to BAT on ItsyBitsy nRF52840Ground from Lipo Backpack to GND on ItsyBitsy nRF528405V from Lipo Backpack to USB on ItsyBitsy nRF52840

Slide Switch

A 2-pin slide switch is wired to the switch pins on the Trinket/ItsyBitsy Lipo Backpack as shown in the diagram above.


http://fritzing.org/download/

https://github.com/adafruit/Fritzing-Library/tree/master/parts

Heart with NeoPixel Strips

The heart is made of up several strips of NeoPixels. The separate pieces will be wired together in a "daisy chain".Reference the labels on each strip to ensure polarity is correct. The diagram features labels for referencing the pixelnumber and the flow of data in and data out. The pixels are wired from top to bottom, left to right. The neopixel at theend of each row will need to flow into the far left neopixel on the subsequent row.

5V+ from NeoPixel Strip to Vhi on ItsyBitsy nRF52840G from NeoPixel Strip to G on ItsyBitsy nRF52840DIN from NeoPixel Strip to Pin #5 on ItsyBitsy nRF52840


CircuitPython

Setup the ItsyBitsy nRF52840 with CircuitPython

We'll need to get our board setup so we can run the CircuitPython code. Let's walk through these steps to get thelatest version of CircuitPython onto your board.

The Mu Python Editor

Mu is a simple Python editor that works with Adafruit CircuitPython hardware. It's written in Python and works onWindows, MacOS, Linux and Raspberry Pi. The serial console is built right in, so you get immediate feedback from yourboard's serial output! While you can use any text editor with your code, Mu makes it super simple. Instructions for Muare available here (https://adafru.it/ANO).

Installing or upgrading CircuitPython

You should ensure you have CircuitPython 4.0 or greater on your board. Plug your board in with a known good data +power cable (not the cheesy USB cable that comes with USB power packs, they are power only). You should see anew flash drive pop up.

If the drive is CIRCUITPY, then open the boot_out.txt file to ensure the version number is 4.0 or greater.

Adafruit CircuitPython 5.0.0-beta.3 on 2020-01-08; Adafruit ItsyBitsy nRF52840 Express with nRF52840

If you do not have CircuitPython on your board, you can add it or upgrade via this page on the ItsyBitsyguide (https://adafru.it/IXe).

Download the Adafruit CircuitPython Library Bundle


https://learn.adafruit.com/welcome-to-circuitpython/installing-mu-editor

https://learn.adafruit.com/adafruit-itsybitsy-nrf52840-express/circuitpython

In order to run the code, we'll need to download a few libraries. Libraries contain code to help interface with hardwarea lot easier for us.

Use the ItsyBitsy nRF52840 page on Installing Libraries (https://adafru.it/Ie7) to get the library that matches the majorversion of CircuitPython you are using noted above, i.e. 4.x for the versions starting with 4, 5.x for the versions startingwith 5, etc.

To run the code for this project, we need the three libraries in the Required Libraries list below. Unzip the librarybundle and search for the libraries. Drag and drop the files into a folder named lib on the CIRCUITPY drive (whichappears when your board is plugged into your computer via a known good USB cable) if the directory is not already onthe ItsyBitsy nRF52840).

Required Libraries

neopixel.mpyadafruit_bluefruit_connectadafruit_ble

Once we have all the files we need, a directory listing will look similar to above as far as files and directories.

Upload Code

Click on the download link below to grab the main code directly from GitHub. Ensure the file is named code.py anddrop it onto the CIRCUITPY drive main (root) directory that appears when your ItsyBitsy nRF52840 is plugged into yourcomputer via a known good USB data cable. The code will run properly when all of the files have been uploadedincluding libraries.

Use any text editor or favorite IDE to modify the code. We suggest using Mu as noted above.

import timeimport boardimport neopixelfrom adafruit_ble import BLERadiofrom adafruit_ble.advertising.standard import ProvideServicesAdvertisementfrom adafruit_ble.services.nordic import UARTServicefrom adafruit_bluefruit_connect.packet import Packetfrom adafruit_bluefruit_connect.button_packet import ButtonPacketfrom adafruit_bluefruit_connect.color_packet import ColorPacket


https://circuitpython.org/board/itsybitsy_nrf52840_express/

from adafruit_bluefruit_connect.color_packet import ColorPacket

# NeoPixel strip data pinpixel_pin = board.D5

# The number of NeoPixelsnum_pixels = 46

# Increase or decrease between 0 and 1 to increase or decrease the brightness of the LEDsbrightness = 0.1

# The order of the pixel colors - RGB or GRB. Some NeoPixels have red and green reversed!ORDER = neopixel.GRB

pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=brightness, auto_write=False, pixel_order=ORDER)# BLE Setupble = BLERadio()uart_service = UARTService()advertisement = ProvideServicesAdvertisement(uart_service)

#Wheel function for rainbowsdef wheel(pos): # Input a value 0 to 255 to get a color value. # The colours are a transition r - g - b - back to r. if pos < 0 or pos > 255: r = g = b = 0 elif pos < 85: r = int(pos * 3) g = int(255 - pos * 3) b = 0 elif pos < 170: pos -= 85 r = int(255 - pos * 3) g = 0 b = int(pos * 3) else: pos -= 170 r = 0 g = int(pos * 3) b = int(255 - pos * 3) return (r, g, b) if ORDER in (neopixel.RGB, neopixel.GRB) else (r, g, b, 0)

#Rainbow Swirl Animationdef rainbow_swirl(wait): for j in range(255): for i in range(num_pixels): pixel_index = (i * 256 // num_pixels) + j pixels[i] = wheel(pixel_index & 255) pixels.show() time.sleep(wait)

#Rainbow Fill Animationdef rainbow_fill(wait): for j in range(255): for i in range(num_pixels): pixel_index = int(i + j) pixels[i] = wheel(pixel_index & 255) pixels.show() time.sleep(wait)


time.sleep(wait)

# List of colorsRED = (255, 0, 0)ORANGE = (255, 50, 0)BLACK = (0, 0, 0)GREEN = (0, 255, 0)PURPLE = (100, 0, 255)YELLOW = (255,230, 0)BLUE = (0, 0, 255)

while True: while ble.connected: if uart_service.in_waiting: if uart_service.in_waiting: packet = Packet.from_stream(uart_service) if isinstance(packet, ColorPacket): # Set all the pixels to one color and stay there. pixels.fill(packet.color) pixels.show() elif isinstance(packet, ButtonPacket): if packet.pressed: if packet.button == ButtonPacket.BUTTON_1: pixels.fill(BLUE) pixels.show() elif packet.button == ButtonPacket.BUTTON_2: pixels.fill(RED) pixels.show() elif packet.button == ButtonPacket.BUTTON_3: rainbow_swirl(0.01) pixels.show() elif packet.button == ButtonPacket.BUTTON_4: rainbow_fill(0.001) elif packet.button == ButtonPacket.DOWN: pixels.fill(BLACK) pixels.show()

Double Check

See the directory listing above and double check that you have all the files listed to make this project function. If anyare missing or in an incorrect directory, move them so they're in the right places.


Bluefruit LE ConnectApp

Bluetooth AppThis project uses the Adafruit Bluefruit LE connect app

(available free for Android and iOS) to trigger the LEDs.

It uses the control pad to trigger up to 8 different colors.

If you haven't downloaded the app yet, use the button

below to install it on your mobile device.

https://adafru.it/ddu

https://adafru.it/ddu

https://adafru.it/f4G

https://adafru.it/f4G

Connect to ItsyBitsy nRF52840

Power on the ItsyBitsy nRF52840 by connecting it via USB to your computer.

Using Bluefruit LE Connect App

Open the Bluefruit LE Connect app and locate the device named CIRCUITPY and tap the connect button. Locate andtap on Controller. Under module, tab on Control Pad.

Use the 1-4 buttons to cycle between the two preset colors and rainbow animations.

Color Picker

You can change the color of the animations by using the Color Picker. Tap connect, select Controller. Under module,tap on Color Picker. Use the color wheel to select a color and the slider to adjust the brightness. Tap the send colorbutton to trigger the color.

Apple Watch

If you have an Apple Watch, you can use the Bluefruit LE Connect App just like the mobile app. The Apple Watch appis included with the iOS app download.



https://itunes.apple.com/us/app/adafruit-bluefruit-le-connect/id830125974?mt=8

https://play.google.com/store/apps/details?id=com.adafruit.bluefruit.le.connect

Milling Acrylic

Black LED AcrylicPre cut sheets of Chemcast Black LED

acrylic (https://adafru.it/IVf) can be purchased from TAP

Plastics. This acrylic allows the colors of the LEDs to

shine through and features a nice matte finish.

Acrylic Sheet Size:

width: 100mm

height: 100mm

thickness: 1/8in (~2.8mm)

Bantam Tools CNCIn this project, we're using the Bantam Tools desktop

CNC milling machine (https://adafru.it/Cg-) to cut out the

heart cover. An 1/8in single flute upcut endmill is used to

cut the acrylic.

1/8in Single FLute Upcut End

Mill (https://adafru.it/IVA)

Generate ToolpathThe acrylic heart cover was designed in Fusion 360. A

2D contour is used to create the outline using an 1/8in

flat end mill. The stock acrylic measures roughly ~2.8mm

thick and 100mm x 100mm. Max roughing stepdown of

0.2mm is used for cutting multiple depths.

Feeds & Speeds

Spindle: 16400 RPM

Cutting feedrate: 1500 mm/min

Plunge feedrate: 46 mm/min

https://adafru.it/IVB








https://cdn-learn.adafruit.com/assets/assets/000/088/237/original/black-acrylic-heart.zip?1581281089

https://adafru.it/IVB

Download GCode

The toolpath was generated using the Othermill(otherplan) post processor and exported from the manufacturingworkspace in Fusion 360. Download the zip file below and make sure the gcode's file extension uses .nc

https://adafru.it/IVC

https://adafru.it/IVC

Bantam Tools SetupSet the material to generic using the dropdown menu.

Enter in the width, height and thickness so they match

our stock material.

width: 100mm

height: 100mm

thickness: 2.8mm

The material placement is set to be aligned at left of the

spoilboard origin.


https://www.bantamtools.com/software-download


Plan SetupOpen the gcode .nc file using the open file button in the

plans section. Set the XYZ placement and enter the

values below:

X: 2mm

Y: 2mm

X: 0mm

Milling ToolsSelect the 1/8in Flat End Mill from the dropdown menu

in the milling tools section.

Install & Probe End MillChange the tool using the change tool button in the

bantam tool software. Install the 1/8in end mill and select

it from the dropdown menu when it's prompt. The tool

will slowly plunge and touch the spoilboard to probe the

tool.




Secure Stock to SpoilboardUse the shiny side of the black LED acrylic to adhere to

the spoildboard. Strips of double-sided tape is used to

adhere the acrylic stock to the spoilboard. The acrylic is

placed at the lower left corner of the spoilboard.

Start MillingOnce the end mill and stock has been installed, it's time

to start milling! The cutting job takes around 7-8 minutes

to complete.




Vacuum SnowOnce the cutting job is complete, you'll want to clean up

the acrylic swarf shavings. A tiny tube style attachment

can be quite helpful as it can get into all of the nooks

and crannies.

Remove Acrylic HeartUse alcohol to soften the adhesive from the tape. A

palette knife or spatula can be used to get underneath

the stock to pop it free.




Heart Shape Acrylic CoverUse paper towel with a bit of alcohol to wipe the acrylic

piece clean. Now it's ready to use in our project! Go

ahead and try press fitting it into the 3D printed heart

case.



Assembly

Cut StripMeasure a strip of NeoPixels 46 pixels long and then cut

each to fit the heart shape in a 8x9 grid.

Add TapeUse packing tape to hold the strips in shape. Add

additional tape strips to fit the last pixel.




Trim TapeCut off the excess tape from the sides.

Strip padsUse a hobby knife to carefully cut away the tape from

the pads on each strip.




Trim wiresMeasure each pad length and cut all wires to reach.

Tin padsCarefully tin each pad on the strips. Use additional strips

of tape if the tape melts from tinning the pads.




Solder padsUse third helping hands to hold the strips and solder

each wires to the pads.

Tin and solder ItsyBitsyTin and solder the Vin, 5! and G pins on the ItsyBitsy to

Power, Data and Ground wire to the pads on each strip.




Prep BackpackTo enable the slide switch, we'll need to cut the trace

close to the mounting holes. Use flush cutters to cut the

trace by using the mounting hole as an anchor. The lipo

backpack is wired to the BAT, Ground and USB pins on

the ItsyBitsy board.

Solder Slide SwitchTwo wires are soldered to the switch pins on the lipo

backpack. You’ll want to tin the leads on the slide

switch with a bit of solder. Solder the wires to the

middle pin and either the far left or right.




Mount boardsThe ItsyBitsy board snap fits into the case and is held in

place with tabs. Align the USB port to the cutout on the

case and press fit into place.

The Lipo backpack is pressed into place and the slide

switch fits into a little built-in holder.

Attach NinjaFlex A piece of ninjaflex can be used to create the second

strap to form our necklace.

The wiring and filament are inserted into the slits on the

side of the case.




Place batteryThis 500mah lipo battery can then be connected to the

JST connector on the Lipo backpack.

Reset buttonA little button is placed over the reset and then the

cover can be pressed on top.

Fit Acrylic coverThe LED matrix is fitted inside the heart case with the

wiring and filament fitted through the slits.

After that, the acrylic can then be fitted on top and there

you have it!






© Adafruit Industries Last Updated: 2020-05-05 02:35:07 PM EDT Page 32 of 32

Documents

NeoPixel LED Heart Necklace - Adafruit Industries · BLE with ItsyBitsy You can change the colors of the LEDs using the Adafruit BLE Connect app for iOS or Android. You can also trigger