# Christmas Soundboard with NeoTrellis M4 ## Overview https://youtu.be/wZzvNoJP0uk This guide shows you how to build your own [soundboard](https://en.wikipedia.org/wiki/Soundboard_(computer_program)). Soundboards are commonly used for sound effects or to select various pieces of dialog on command, though this one features a set of open-source holiday audio clips for bountiful fun and mischief this holiday season. This project uses the [NeoTrellis M4](https://www.adafruit.com/product/3938) to create a soundboard capable of playing any of 32 audio clips when the corresponding button is pressed. Sounds are able to seamlessly interrupt one another, so you can press as messily as you like and this soundboard will keep up with you.  ![](https://cdn-learn.adafruit.com/assets/assets/000/066/382/medium800thumb/circuitpython_color_wave.2018-11-24_01_15_34.jpg?1543041720) ## About the NeoTrellis M4 The NeoTrellis M4 is an all-in-one Audio board, ready to become your next synth, soundboard, drum machine, keyboard, or any other invention you'd like to adapt it for. It’s powered by the SAMD51, a Cortex M4 core running at 120 MHz, featuring a roomy 512KB of flash and 192KB of SRAM. A separate flash chip provides a full 8MB of space for files and audio clips. On the front side is a 4x8 grid of elastomer button pads with a NeoPixel nestled in the center of each one. You can read any/all button presses simultaneously thanks to the fully diode'd matrix, and also set each button color to any of 24-bit colors. ## Parts ### Adafruit NeoTrellis M4 with Enclosure and Buttons Kit Pack [Adafruit NeoTrellis M4 with Enclosure and Buttons Kit Pack](https://www.adafruit.com/product/4020) So you've got a cool/witty name for your band, a Soundcloud account, [a 3D-printed Daft Punk helmet](https://learn.adafruit.com/3d-printed-daft-punk-helmet-with-bluetooth)... so what could be missing from your road to stardom? The **NeoTrellis M4 Kit...** Out of Stock [Buy Now](https://www.adafruit.com/product/4020) [Related Guides to the Product](https://learn.adafruit.com/products/4020/guides) ![Demo Video of Hands pressing buttons on lit up NeoTrellis M4.](https://cdn-shop.adafruit.com/product-videos/640x480/4020-00.jpg) ### USB cable - USB A to Micro-B [USB cable - USB A to Micro-B](https://www.adafruit.com/product/592) This here is your standard A to micro-B USB cable, for USB 1.1 or 2.0. Perfect for connecting a PC to your Metro, Feather, Raspberry Pi or other dev-board or microcontroller Approximately 3 feet / 1 meter long In Stock [Buy Now](https://www.adafruit.com/product/592) [Related Guides to the Product](https://learn.adafruit.com/products/592/guides) ![USB cable - USB A to Micro-B - 3 foot long](https://cdn-shop.adafruit.com/640x480/592-01.jpg) Pick how you would like your sound output: ### USB Powered Speakers [USB Powered Speakers](https://www.adafruit.com/product/1363) Add some extra boom to your audio project with these powered loudspeakers. We sampled half a dozen different models to find ones with a good frequency response, so you'll get quality audio output for music playback. Simply connect the standard 3.5mm stereo plug into your Raspberry Pi model... In Stock [Buy Now](https://www.adafruit.com/product/1363) [Related Guides to the Product](https://learn.adafruit.com/products/1363/guides) ![Two square-ish USB Powered Speakers](https://cdn-shop.adafruit.com/640x480/1363-07.jpg) Or if you have something that takes audio in, you might consider this cable: ### 3.5mm Male/Male Stereo Cable [3.5mm Male/Male Stereo Cable](https://www.adafruit.com/product/2698) Seamlessly transmit high-quality stereo audio with this  **3.5mm Male/Male Stereo Cable. ** Ideal for "passing the AUX cord," or connecting audio devices such as smartphones, tablets, MP3 players, car stereos, portable speakers or any other... In Stock [Buy Now](https://www.adafruit.com/product/2698) [Related Guides to the Product](https://learn.adafruit.com/products/2698/guides) ![Black audio cable with 3.5mm audio jacks wrapped like a bow tie.](https://cdn-shop.adafruit.com/640x480/2698-01.jpg) ### For on the go power with headphones: ### Part: USB Battery Pack - 2200 mAh quantity: 1 USB Battery Pack - 2200 mAh Capacity - 5V 1A Output [USB Battery Pack - 2200 mAh ](https://www.adafruit.com/product/1959) or for use with speakers: ### Part: USB Battery Pack - 10000mAh quantity: 1 USB Battery Pack - 10000mAh - 2 x 5V outputs [USB Battery Pack - 10000mAh ](https://www.adafruit.com/product/1566) Info: # Christmas Soundboard with NeoTrellis M4 ## Enclosure Assembly ![](https://cdn-learn.adafruit.com/assets/assets/000/065/541/medium800/adafruit_products_3963-06.jpg?1541982947) The acrylic enclosure is quick and easy to assemble. Each part is horizontally symmetrical, so there is very little worry about placing them in a "wrong" direction. ## Prep First, you have the satisfying task of peeling off the protective paper from the acrylic pieces. If you peel off all of the paper without tearing them you will have seven weeks of good luck. Do not squander them. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/543/medium800/adafruit_products_IMG_2336_2k.jpg?1541983108) ![](https://cdn-learn.adafruit.com/assets/assets/000/065/546/medium800/adafruit_products_IMG_2342_2k.jpg?1541983171) ## Elastomer Pads Place both of the button pads into the top piece as shown. Note, there are two pairs of rubber registration nubs which must align with their associated holes on the Trellis M4 board, so match the orientation as seen in the photos. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/552/medium800/adafruit_products_IMG_2343_2k.jpg?1541983311) ## Place the Trellis M4 Place the Trellis M4 board down onto the elastomer pads with the NeoPixels and button contacts aligned with the buttons as shown. Make sure all of the sixteen registration nubs fit into their associated holes on the PCB. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/561/medium800/adafruit_products_IMG_2346_2k.jpg?1541984539) ![](https://cdn-learn.adafruit.com/assets/assets/000/065/569/medium800/adafruit_products_IMG_2347_2k.jpg?1541984554) ## Frame Layer Now, place the frame layer which helps hold the board in place. ## Penultimate Layer This next layer has some large cutouts in it to allow for parts clearance. ## Back Layer It's the final layer! Lay it down and get ready for some fastening action. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/581/medium800/adafruit_products_IMG_2357_2k.jpg?1541984797) ## Fasteners Place the five nylon M3 screws through their holes from the front of the case toward the back, then thread the nuts onto them and finger tighten. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/596/medium800/adafruit_products_IMG_2358_2k.jpg?1541984856) ![](https://cdn-learn.adafruit.com/assets/assets/000/065/613/medium800/adafruit_products_IMG_2363_2k.jpg?1541984980) Your Trellis M4 is ready for use! ![](https://cdn-learn.adafruit.com/assets/assets/000/065/631/medium800/adafruit_products_IMG_2368_2k.jpg?1541985245) ## Customization Are you the sort of tinkerer who feels the urge to customize things? We knew it! In case you want to try your hand at building a custom enclosure for your Trellis M4, and make all your other DJ/Producer friends jealous, [here are the CAD files to get you started](https://github.com/adafruit/Adafruit-NeoTrellis-M4-PCB-and-Enclosure). Use them on a laser cutter to created a unique wooden faceplate. Or, print the top piece out with ill graphics on a color printer, trim the button holes and screw holes, and make a cool skin. You might even want to use the templates as a reference for 3D modelling a case! It's easy to press the Trellis M4's reset button through the case using a small object such as a headphone plug, chopstick, or 5mm LED. But, if you're doing a lot of development in Arduino and resetting a lot, you may want to make a button extender. Here's a file you can 3D print for that! [resetbuttonTrellisM4.stl.zip](https://cdn-learn.adafruit.com/assets/assets/000/067/748/original/resetbuttonTrellisM4.stl.zip?1545149910) # Christmas Soundboard with NeoTrellis M4 ## Trellis M4 Setup First, we'll prep the Trellis M4 for running CircuitPython. After assembling the case, plug your NeoTrellis into a computer (mac/PC/Linux) and look for a new flash drive in the operating system file explorer/finder program. It should be named **CIRCUITPY**. If you browse the files on this new drive, you'll see a file named **boot\_out.txt**. If you see this, then you should be set. If not, go to troubleshooting below. ## CircuitPython The NeoTrellis M4 Express will be programmed using CircuitPython, the easy to use language on Adafruit's Express products. No coding is needed if you will just be copying the files in this guide. If you'd like to know more about CircuitPython, [there is a full getting started guide here](https://learn.adafruit.com/welcome-to-circuitpython). To get the latest version of CircuitPython, please see the [instructions in the NeoTrellis Guide](https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython). The code is in text files so you can easily make changes with your favorite text editor. Adafruit suggests using the Mu editor to edit your code and have an interactive REPL in CircuitPython. [You can learn about Mu and its installation in this tutorial](https://learn.adafruit.com/welcome-to-circuitpython/installing-mu-editor). Info: ## Libraries The code uses several libraries for helper code. Please go to the [CircuitPython libraries releases page](https://github.com/adafruit/Adafruit_CircuitPython_Bundle/releases/) and download the zip file for CircuitPython 4.x to your computer hard drive. It will have a name similar to  **adafruit-circuitpython-bundle-4.x-mpy-20181211.zip** but the date will most likely be different (as Adafruit adds more features), Go into the library zip file and copy the following files to your NeoTrellis **CIRCUITPY** drive into a subdirectory named **/lib** : - Directory **adafruit\_bus\_device** - Directory **adafruit\_fancyled** - **adafruit\_adxl34x.mpy** - **adafruit\_matrixkeypad.mpy** - **adafruit\_trellism4.mpy** - **neopixel.mpy** ![](https://cdn-learn.adafruit.com/assets/assets/000/067/478/medium800/circuitpython_christmas-lib.png?1544648513) ## Troubleshooting You can use the serial capability in [Mu](https://learn.adafruit.com/welcome-to-circuitpython/installing-mu-editor) to connect to the NeoTrellis M4 to interact with the CircuitPython prompt. You can see error messages, restart the program, etc.  **Problem: ** I don't see the  **CIRCUITPY**  drive when I plug the NeoTrellis M4 into my computer or I see a drive named  **TRELM4BOOT**  instead. **Solution: ** Ensure CircuitPython is installed via [this guide](https://learn.adafruit.com/adafruit-neotrellis-m4) **.** **Problem: ** The code does not run. **Solution:**  Check the files on the  **CIRCUITPY**  drive.  ** /lib**  should have the latest CircuitPython 4.x libraries and you have placed  **code.py**  in the main (root) directory. **Problem:**  Not enough disk space for all the files. **Solution:**  If you have files from another NeoTrellis project, you may have to remove some or all of the other project-specific files to load files specific to this project. If you use your own phrases, you cannot use long stereo clips or songs for each button, there is not enough flash disk space. You can reduce the number of files below 32. You can trim your clips to make them shorter. You should ensure all your clips are mono instead of stereo.  **Problem** : My board isn't booting up! **Solution** : Make sure your  **/lib**  folder is set up with the libraries in the 4.0 latest release. **Problem:**  I'm not hearing any sounds! **Solution:**  Ensure you have copied the sound files to the appropriate directories: **/xmas** holds 32 sound files. The files are in GitHub in a ZIP when you download the code. Ensure you have headphones or powered speakers plugged into the sound output jack and that the volume is set appropriately. If you have put custom sounds on the NeoTrellis, check that all your files are formatted as Mono 16-bit, 22,050Hz, PCM.  ## Next Your Trellis M4 is now prepped to run CircuitPython code. Next, we'll add the sound and code files. # Christmas Soundboard with NeoTrellis M4 ## Code and Audio Files Time to download the software and sounds. Connect your NeoTrellis M4 to your computer via a known good power+data USB cable. Your computer (PC/Mac/Linux/Chromebook) should indicate in the file explorer/finder a new flash disk drive named **CIRCUITPY**. Click on the **Download Project Zip** button in the top left of the code listing below to get a zip file of all the needed project files. This includes: - **code.py** - **color\_names.py** - **welcome.wav** - **/xmas** subdirectory (contains 32 pre-made audio clips) Open the ZIP file in your computer File Explorer/Finder. Plug in your NeoTrellis and open the **CIRCUITPY** flash drive that appears when NeoTrellis is plugged in. Copy **code.py** , **color\_names.py** and **welcome.wav** to the root/main directory. Copy the directory of sounds, **/xmas**  to the root directory. Files that have a period in the first character of the filename may be made on Mac computers, no worries. Danger: https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/Christmas_Soundboard/code.py ![](https://cdn-learn.adafruit.com/assets/assets/000/067/386/medium800/circuitpython_xmas_soundboard_and_CIRCUITPY_and_Adafruit_Learning_System.jpg?1544460702) # Christmas Soundboard with NeoTrellis M4 ## Happy Holidays Your soundboard is now ready to make some noise! Have fun making weird holiday music, or interjecting sound effects into your conversations.  ![](https://cdn-learn.adafruit.com/assets/assets/000/066/383/medium800thumb/circuitpython_soundboard_demo.2018-11-24_01_33_09.jpg?1543041745) ## Custom Colors You can change the soundboard to display any 4x8 scene you want. Open a file using the Mu editor or a text file editor of your choice. You can do this by changing the  **code.py**  file to assign specific colors to any of the 32 buttons in the array. You can also edit the  **color\_names.py**  file to add or change colors if you want a new palette to work with.  ![](https://cdn-learn.adafruit.com/assets/assets/000/066/375/medium800/circuitpython_IMG_0704.jpg?1543010346) # Christmas Soundboard with NeoTrellis M4 ## Sound Customization ![](https://cdn-learn.adafruit.com/assets/assets/000/067/457/medium800/circuitpython_blinka-trellis_350x302.jpg?1544645699) Sound clips have been trimmed and edited from the following free audio files: - 01 ["Nov. 24, 2006 Parade" by daveincamas](https://freesound.org/people/daveincamas/sounds/26270/)  - 02 ["Metal poles" by Percy Duke](https://freesound.org/people/Percy%20Duke/sounds/28028/)  - 03 ["Ice skating" by inchadney ](https://freesound.org/people/inchadney/sounds/66151/) - 04 ["Beads being shaken to the Christmas Bells melody" by monnie101](https://freesound.org/people/monnie101/sounds/85305/)  - 05 ["Trenet de Nadal" by paubg\_pou](https://freesound.org/people/paubg_pou/sounds/110957/)  - 06 ["Merry Christmas" by davidbain](https://freesound.org/people/davidbain/sounds/136777/)  - 07 ["Christmas pagent" jgeralyn](https://freesound.org/people/jgeralyn/sounds/138160/)  - 08 ["Bells ringing at Notre-Dame" by Mxsmanic](https://freesound.org/people/Mxsmanic/sounds/139103/)  - 09 ["Pirotecnia navidad" by lliban](https://freesound.org/people/lliban/sounds/140058/) - 10 ["Opening a Christmas present" by escortmarius](https://freesound.org/people/escortmarius/sounds/141123/) - 11 ["Spinning a dreidel" by Halleck](https://freesound.org/people/Halleck/sounds/19330/) - 12 ["Merry christmas and a happy new year" by sovy](https://freesound.org/people/sovy/sounds/172303/)  - 13 ["Brass band plays Christmas songs" by dobroide](https://freesound.org/people/dobroide/sounds/172519/) - 14 ["Church bells" by vonfleisch](https://freesound.org/people/vonfleisch/sounds/212037/)  - 15 ["Fast sleigh bells" by jcdecha](https://freesound.org/people/jcdecha/sounds/235465/) - 16 ["Jingle bells" by xtrgamr ](https://freesound.org/people/xtrgamr/sounds/259309/) - 17 ["Musical Snow Globe - We Wish You A Merry Christmas" by mhtaylor67](https://freesound.org/people/mhtaylor67/sounds/260556/)  - 18 ["The bells of Santa Claus" by BrianJamesLong](https://freesound.org/people/BrianJamesLong/sounds/330415/) - 19 ["Merry Christmas" by maurolupo](https://freesound.org/people/maurolupo/sounds/331131/) - 20 ["Hanukkah" by tim.kahn](https://freesound.org/people/tim.kahn/sounds/80212/)  - 21 ["Santa Claus is coming to town" by dwightsabeast](https://freesound.org/people/dwightsabeast/sounds/329372/) - 22 ["Ambient Christian bells" by Npeo](https://freesound.org/people/Npeo/sounds/362796/) - 23 ["We Wish You a Merry Christmas music box" by MaestroALF](https://freesound.org/people/MaestroALF/sounds/399114/) - 24 ["Deck The Halls - Christmas jingle played with bells" by Ihaksi](https://freesound.org/people/Ihaksi/sounds/411420/) - 25 ["Christmas bell" by erickvillegas1986](https://freesound.org/people/erickvillegas1986/sounds/414316/) - 26 ["Electronic Christmas decoration" by richwise](https://freesound.org/people/richwise/sounds/414374/) - 27 ["Sounds of Christmas theme on Freeware Little Piano" by Josiel Soares](https://freesound.org/people/zyga3d/sounds/422105/)  - 28 ["Magic Christmas music" by Lena Orsa](https://freesound.org/people/lena_orsa/sounds/442791/)  - 29 ["Elves laughing" by Mike Koenig](http://soundbible.com/170-Elves-Laughing-High-Pitch.html) - 30 ["Sneeze" by Halleck](https://freesound.org/people/Halleck/sounds/19330/) - 31 ["Sunday Church ambiance" by lezer](http://soundbible.com/1264-Sunday-Church-Ambiance.html) - 32 ["Snow mobile sound" by NPS.gov](http://soundbible.com/1023-Snow-Mobile.html) - welcome ["Merry Christmas sound effects" by airmedia](https://freesound.org/people/airmedia/sounds/349855/) If you'd like to add or update the sounds on your soundboard, more audio clips can be downloaded from sites like [http://soundbible.com/](http://soundbible.com/) or [https://freesound.org/](https://freesound.org/).  You will need to convert the files to the appropriate format for microcontroller use. See [this guide](https://learn.adafruit.com/microcontroller-compatible-audio-file-conversion) on how to do that. When you have a file converted, you can name it like the files in the  **xmas**  directory. For example, say you downloaded a clip and you wanted it to be activated on the second row, end key. That is the 16th key counting from upper left. Rename  **16.wav**  to  **16-old.wav**  and name your clip  **16.wav**  and copy it into the xmas folder on the CIRCUITPY drive. Now your sound will play when that button is pressed. Note for keys 1 to 9, add a leading zero, like  **01.wav** ,  **02.wav** , etc. so all filenames are two digits. ## No Mix & Match on mono and stereo files, please. Make sure your audio files are exported as ** 16-bit PCM WAV**  at  **22,050 Hz**  and they are  **all Stereo**  or  **all Mono**  -_no mix and match_! # Christmas Soundboard with NeoTrellis M4 ## Troubleshooting ## Troubleshooting Project produces error:  > AttributeError: 'WaveFile' object has no attribute 'channel\_count' You should update the NeoTrellis firmware as described in [https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython](https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython). ## Featured Products ### Adafruit NeoTrellis M4 with Enclosure and Buttons Kit Pack [Adafruit NeoTrellis M4 with Enclosure and Buttons Kit Pack](https://www.adafruit.com/product/4020) So you've got a cool/witty name for your band, a Soundcloud account, [a 3D-printed Daft Punk helmet](https://learn.adafruit.com/3d-printed-daft-punk-helmet-with-bluetooth)... so what could be missing from your road to stardom? The **NeoTrellis M4 Kit...** Out of Stock [Buy Now](https://www.adafruit.com/product/4020) [Related Guides to the Product](https://learn.adafruit.com/products/4020/guides) ### USB cable - USB A to Micro-B [USB cable - USB A to Micro-B](https://www.adafruit.com/product/592) This here is your standard A to micro-B USB cable, for USB 1.1 or 2.0. Perfect for connecting a PC to your Metro, Feather, Raspberry Pi or other dev-board or microcontroller Approximately 3 feet / 1 meter long In Stock [Buy Now](https://www.adafruit.com/product/592) [Related Guides to the Product](https://learn.adafruit.com/products/592/guides) ### USB Powered Speakers [USB Powered Speakers](https://www.adafruit.com/product/1363) Add some extra boom to your audio project with these powered loudspeakers. We sampled half a dozen different models to find ones with a good frequency response, so you'll get quality audio output for music playback. Simply connect the standard 3.5mm stereo plug into your Raspberry Pi model... In Stock [Buy Now](https://www.adafruit.com/product/1363) [Related Guides to the Product](https://learn.adafruit.com/products/1363/guides) ### Analog Potentiometer Volume Adjustable TRRS Headset [Analog Potentiometer Volume Adjustable TRRS Headset](https://www.adafruit.com/product/3959) Most modern headphone sets are purely digital - with three volume control buttons in-line with the cable. These headphones are interesting in that they have an _analog_ volume control potentiometer. Perfect for use with electronic projects that don't have volume control, or for... No Longer Stocked [Buy Now](https://www.adafruit.com/product/3959) [Related Guides to the Product](https://learn.adafruit.com/products/3959/guides) ### 3.5mm Male/Male Stereo Cable [3.5mm Male/Male Stereo Cable](https://www.adafruit.com/product/2698) Seamlessly transmit high-quality stereo audio with this  **3.5mm Male/Male Stereo Cable. ** Ideal for "passing the AUX cord," or connecting audio devices such as smartphones, tablets, MP3 players, car stereos, portable speakers or any other... In Stock [Buy Now](https://www.adafruit.com/product/2698) [Related Guides to the Product](https://learn.adafruit.com/products/2698/guides) ### Adafruit NeoTrellis M4 Mainboard - featuring SAMD51 [Adafruit NeoTrellis M4 Mainboard - featuring SAMD51](https://www.adafruit.com/product/3938) We got a big ol' blender and tossed in an ItsyBitsy M4, two NeoTrellis boards and an electret mic amp - turned on the 'mix' button and out came the NeoTrellis M4 - a super fun dev board for anyone who likes to squish buttons, see pretty lights and maybe make a tune or... In Stock [Buy Now](https://www.adafruit.com/product/3938) [Related Guides to the Product](https://learn.adafruit.com/products/3938/guides) ### NeoTrellis M4 Acrylic Enclosure Kit [NeoTrellis M4 Acrylic Enclosure Kit](https://www.adafruit.com/product/3963) So you've got your [Adafruit NeoTrellis M4](https://www.adafruit.com/product/3938), a cool/witty name for your band, a Soundcloud account, [a 3D-printed Daft Punk helmet](https://learn.adafruit.com/3d-printed-daft-punk-helmet-with-bluetooth)... so what... Out of Stock [Buy Now](https://www.adafruit.com/product/3963) [Related Guides to the Product](https://learn.adafruit.com/products/3963/guides) ### Silicone Elastomer 4x4 Button Keypad - for 3mm LEDs [Silicone Elastomer 4x4 Button Keypad - for 3mm LEDs](https://www.adafruit.com/product/1611) So squishy! These silicone elastomer keypads are just waiting for your fingers to press them. Go ahead, squish all you like! (They're durable and easy to clean, just wipe with mild soap and water) These are just like the light up rubber buttons you find on stuff like appliances and tools,... Out of Stock [Buy Now](https://www.adafruit.com/product/1611) [Related Guides to the Product](https://learn.adafruit.com/products/1611/guides) ## Related Guides - [Adafruit NeoTrellis M4 Express](https://learn.adafruit.com/adafruit-neotrellis-m4.md) - [Trellis M4 Expressive MIDI Controller](https://learn.adafruit.com/trellis-m4-midi-keypad-and-tilt-controller.md) - [NeoTrellis Light Painting](https://learn.adafruit.com/neotrellis-light-painting.md) - [Bringing Back THE VOICE of Speak & Spell](https://learn.adafruit.com/bringing-back-the-voice-of-speak-spell.md) - [AdaBox 010](https://learn.adafruit.com/adabox010.md) - [Adafruit NeoTrellis](https://learn.adafruit.com/adafruit-neotrellis.md) - [FlappyBird Game for NeoTrellis M4 in CircuitPython](https://learn.adafruit.com/circuitpython-neotrellism4-flappybird.md) - [NeoTrellis M4 Memory Game](https://learn.adafruit.com/neotrellis-m4-memory-game.md) - [Trellis Feather DSP-G1 Synthesizer](https://learn.adafruit.com/feather-trellis-dsp-g1-synthesizer.md) - [Star Trek Soundboard with NeoTrellis](https://learn.adafruit.com/star-trek-sound-board-with-neotrellism4.md) - [NeoTrellis M4 MIDI File Synthesizer](https://learn.adafruit.com/neotrellism4-midi-file-player-synthesizer.md) - [NeoTrellis M4 Animated Dice Roller](https://learn.adafruit.com/neotrellis-dice.md) - [UNTZtrument: a Trellis MIDI Instrument](https://learn.adafruit.com/untztrument-trellis-midi-instrument.md) - [CircuitPython on the Xteink X4 eReader](https://learn.adafruit.com/circuitpython-on-the-xteink-x4-ereader.md) - [Adafruit Metro M0 Express](https://learn.adafruit.com/adafruit-metro-m0-express.md) - [Larsio Paint Music](https://learn.adafruit.com/larsio-paint-music.md)