# Adafruit Hallowing M4
## Overview
[This is Hallowing..this is Hallowing... Hallowing! Hallowing! ](https://www.youtube.com/watch?v=kGiYxCUAhks&t=39s)
Following up on 2018's [most-successful-skull-shaped development board](https://www.adafruit.com/product/3900), we UPPED our -skull-shaped development board game, and [re-spinned (re-spun?) the HalloWing M0](https://www.adafruit.com/product/3900) into the HalloWing M4 with MORE of everything that makes this the spoooookiest dev board.
Are you the kind of person who doesn't like taking down the skeletons and spiders until after January? Well, we've got the development board for you. This is electronics at its _most spooky!_ The **Adafruit HalloWing M4** is a skull-shaped ATSAMD51J19A board with a ton of extras built in to make for an adorable wearable, badge, development kit, or the engine for your next cosplay or prop.
On the front is a cute **1.54" sized 240x240 full color IPS TFT.** Compared to the HalloWing M0's 1.44" 128x128, this has 4x as many pixels and is IPS for great color and brightness. [Our default example code has our new fully-customizable spooky eye demo](https://learn.adafruit.com/customeyesation-diy-monster-m4sk-graphics) running but you can use it for anything you like to display in glorious color.
There's also 4 fang-teeth below the display, these are analog/capacitive touch inputs with big alligator-clip holes.
On the reverse is a smorgasbord of electronic goodies:
- **ATSAMD51J19A** @ 120MHz with 3.3V logic/power - 512KB of FLASH + 192KB of RAM, can run Arduino or CircuitPython super fast
- **8 MB of SPI Flash** for storing images, sounds, animations, whatever!
- **3-axis accelerometer** (motion sensor)
- **Light sensor** , reverse-mount so that it points out the front
- **Mono Class-D speaker driver** for 4-8 ohm speakers, up to 1 Watt, connected to a 12-bit DAC on the SAMD51
- **Four side-light NeoPixel LEDs** for cool underlighting effects
- LiPoly battery port with built in recharging capability
- USB port for battery charging, programming and debugging
- Two female header strips with Feather-compatible pinout so you can plug any FeatherWings in
- JST ports for Neopixels, sensor input, and I2C (you can fit I2C Grove connectors in here)
- 3.3V regulator with 500mA peak current output
- Reset button
- On-Off switch
**OK so technically it's more like a really tricked-out Feather M4 Express than a _Wing_ but we simply could not resist the HalloWing pun.**
You can use the Hallowing similarly Feather M4 Express, it's got the same chip although the pins have been rearranged. We've got both Arduino and CircuitPython build support for it so you can pick your favorite development language! The extra 8 MB of SPI Flash is great for sound effects projects where you want to play up to 3 minutes of WAV files.
On each side of the Hallowing are JST-PH plugs for connecting external devices. The 3-pin JSTs connect to analog pins on the SAMD51, so you can use them for analog inputs. We label one for NeoPixel and one for Sensors since we think most people will have one of each. The 4-pin JST connector connects to the I2C port and you can fit Grove connectors in it for additional hardware support.
**Does not come with a Lipoly battery!** [We recommend our 350mAh](https://www.adafruit.com/product/2750) or[500mAh batteries](https://www.adafruit.com/product/1578) but any 3.7/4.2V Adafruit Lipoly will do the trick.
Comes fully assembled and ready to be your spooky skull friend. We install the UF2 bootloader on it so updating code and converting it to CircuitPython is easy
- [Next Page](https://learn.adafruit.com/adafruit-hallowing-m4/update-the-uf2-bootloader.md)
## Primary Products
### Adafruit HalloWing M4 Express - Goth Adafruit Black Edition
[Adafruit HalloWing M4 Express - Goth Adafruit Black Edition](https://www.adafruit.com/product/4300)
[This is Hallowing..this is Hallowing... Hallowing! Hallowing! ](https://www.youtube.com/watch?v=kGiYxCUAhks&t=39s)Following up on 2018's [most-successful-skull-shaped development board](https://www.adafruit.com/product/3900), we UPPED our -skull-shaped...
Out of Stock
[Buy Now](https://www.adafruit.com/product/4300)
[Related Guides to the Product](https://learn.adafruit.com/products/4300/guides)
## Featured Products
### Lithium Ion Polymer Battery Ideal For Feathers - 3.7V 400mAh
[Lithium Ion Polymer Battery Ideal For Feathers - 3.7V 400mAh](https://www.adafruit.com/product/3898)
Lithium-ion polymer (also known as 'lipo' or 'lipoly') batteries are thin, light, and powerful. The output ranges from 4.2V when completely charged to 3.7V. This battery has a capacity of **400mAh** for a total of about 1.9 Wh. If you need a larger (or smaller!)...
In Stock
[Buy Now](https://www.adafruit.com/product/3898)
[Related Guides to the Product](https://learn.adafruit.com/products/3898/guides)
### Adafruit NeoPixel LED Strip with 3-pin JST PH 2mm Connector
[Adafruit NeoPixel LED Strip with 3-pin JST PH 2mm Connector](https://www.adafruit.com/product/3919)
Plug in and glow, this **Adafruit NeoPixel LED Strip with JST PH Connector** has **30 total LEDs** in a **"60 LED per meter" spacing** , and is 0.5 meters long, in classy Adafruit Black. Its not too long, but has lots of glowing action.
Out of Stock
[Buy Now](https://www.adafruit.com/product/3919)
[Related Guides to the Product](https://learn.adafruit.com/products/3919/guides)
### JST PH 2mm 4-Pin to Female Socket Cable - I2C STEMMA Cable
[JST PH 2mm 4-Pin to Female Socket Cable - I2C STEMMA Cable](https://www.adafruit.com/product/3950)
This cable will let you turn a JST PH 4-pin cable port into 4 individual wires with high-quality 0.1" female sockets on the end. We're carrying these to match up with any of our boards with 'STEMMA' connectors on them such as the
Out of Stock
[Buy Now](https://www.adafruit.com/product/3950)
[Related Guides to the Product](https://learn.adafruit.com/products/3950/guides)
### JST PH 2mm 4-Pin to Male Header Cable - I2C STEMMA Cable - 200mm
[JST PH 2mm 4-Pin to Male Header Cable - I2C STEMMA Cable - 200mm](https://www.adafruit.com/product/3955)
This cable will let you turn a JST PH 4-pin cable port into 4 individual wires with high-quality 0.1" male header plugs on the end. We're carrying these to match up with any of our boards with 'STEMMA' connectors on them such as the
In Stock
[Buy Now](https://www.adafruit.com/product/3955)
[Related Guides to the Product](https://learn.adafruit.com/products/3955/guides)
### JST PH 2mm 3-pin Plug to Color Coded Alligator Clips Cable
[JST PH 2mm 3-pin Plug to Color Coded Alligator Clips Cable](https://www.adafruit.com/product/4030)
This cable will let you turn a JST PH 3-pin cable port into 3 individual wires with grippy mini alligator clips. We're carrying these to match up with any of our boards or breakouts with 3-pin 'STEMMA' connectors on them such as the
In Stock
[Buy Now](https://www.adafruit.com/product/4030)
[Related Guides to the Product](https://learn.adafruit.com/products/4030/guides)
### Clear Acrylic Lens Holder + Hardware Kit for HalloWing
[Clear Acrylic Lens Holder + Hardware Kit for HalloWing](https://www.adafruit.com/product/4013)
Here is the perfect kit for mounting a [convex lens](https://www.adafruit.com/?q=convex%20lens%20edge) (glass _or_ plastic) to your [HalloWing](https://www.adafruit.com/product/3900)! This holder has been laser-cut specifically for lenses with a lip-edge, so we...
In Stock
[Buy Now](https://www.adafruit.com/product/4013)
[Related Guides to the Product](https://learn.adafruit.com/products/4013/guides)
### Convex Glass Lens with Edge - 40mm Diameter
[Convex Glass Lens with Edge - 40mm Diameter](https://www.adafruit.com/product/3853)
The eyes have it! Add this little lens to make a big expression with our Spooky Eyes demo for microcontrollers or Raspberry Pi. These are gorgeous glass (_not plastic/acrylic!_) lenses, with brilliant clarity and a nice convexity (is that a word?) They've even got a lip-edge so you...
In Stock
[Buy Now](https://www.adafruit.com/product/3853)
[Related Guides to the Product](https://learn.adafruit.com/products/3853/guides)
### Convex Plastic Lens with Edge
[Convex Plastic Lens with Edge](https://www.adafruit.com/product/3917)
The eyes have it! Add this little lens to make a big expression with our Spooky Eyes demo for microcontrollers or Raspberry Pi. These are plastic lenses, with brilliant clarity and a nice convexity (is that a word?) They've even got a lip-edge so you can mount them easily with a 38mm...
In Stock
[Buy Now](https://www.adafruit.com/product/3917)
[Related Guides to the Product](https://learn.adafruit.com/products/3917/guides)
## Related Guides
- [Milk Jug Glow Skull](https://learn.adafruit.com/milk-jug-glow-skull.md)
- [HalloWing M4 Tombstone](https://learn.adafruit.com/hallowing-tombstone.md)
- [PyPortal NeoPixel Color Picker](https://learn.adafruit.com/pyportal-neopixel-color-picker.md)
- [Hocus Pocus Book - Hallowing Eye](https://learn.adafruit.com/hocus-pocus-book-eye.md)
- [NeoPixel Remote: IR Control with WLED](https://learn.adafruit.com/neopixel-remote-ir-control-with-wled.md)
- [Last-Minute Halloween Accoutrements with HalloWing](https://learn.adafruit.com/last-minute-halloween-accoutrements-with-hallowing.md)
- [No-Code Rain Sensing Smart Desktop Umbrella Stand](https://learn.adafruit.com/no-code-rain-sensing-smart-desktop-umbrella-stand.md)
- [HalloWing All-Seeing Skull](https://learn.adafruit.com/hallowing-all-seeing-skull.md)
- [Feather Guitar Hero Adapter](https://learn.adafruit.com/feather-guitar-hero-adapter.md)
- [Adafruit QT Py and NeoPixel LEDs](https://learn.adafruit.com/qt-py-and-neopixel-leds.md)
- [Wireless LED Juggling Balls with ESP-NOW](https://learn.adafruit.com/wireless-juggling-balls-esp-now.md)
- [Wakanda Forever Game](https://learn.adafruit.com/wakanda-forever-game.md)
- [Terminator Eyeball Upgrade](https://learn.adafruit.com/terminator-eyeball-upgrade.md)
- [AdaBox 009](https://learn.adafruit.com/adabox009.md)
- [A REST API for Arduino & the CC3000 WiFi Chip](https://learn.adafruit.com/a-rest-api-for-arduino-and-the-cc3000-wifi-chip.md)