# Trellis M4 Beat Sequencers ## Overview ![](https://cdn-learn.adafruit.com/assets/assets/000/066/104/medium800/feather_16-step_cover.jpg?1542412545) https://youtu.be/-kW_fp2E6ZE Drum machines make the music world go round. While originally intended to replace real, human drummers (which they never have, thankfully!) drum machines and sequencers played a huge role in creating whole new genres of music from hip hop to electronica, dub to disco. Now, you can get started making your own beats using the Trellis M4 from Adafruit! We'll start with a simple eight-step sequencer, programmed in CircuitPython, and then get a bit more complex with a sixteen-step sequencer that includes effects, beat repeats, and even a live sampler to record your own sounds. Unlike a MIDI-based sequencer, these two sequencers are self-contained, requiring no external synth or computer. Simply plug in an 1/8" audio cable and all of the onboard sounds will play through your amplifier or headphones! ## 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 microcontroller, 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...** In 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) ### Part: Analog Potentiometer Adjustable Headphones quantity: 1 1/8" TRRS connector earbuds with mic and slider [Analog Potentiometer Adjustable Headphones](https://www.adafruit.com/product/3959) ### Part: USB cable - A/MicroB quantity: 1 Standard A to micro-B USB cable - 3ft [USB cable - A/MicroB](https://www.adafruit.com/product/592) ### Part: 3.5mm Male/Male Stereo Cable quantity: 1 1 meter [3.5mm Male/Male Stereo Cable](https://www.adafruit.com/product/2698) ### Part: USB Powered Speakers quantity: 1 Add some extra boom to your audio project with these powered loudspeakers. [USB Powered Speakers](https://www.adafruit.com/product/1363) ### Stereo 3.5mm Plug/Plug Audio Cable - 6 feet [Stereo 3.5mm Plug/Plug Audio Cable - 6 feet](https://www.adafruit.com/product/876) This basic cable comes with two 3.5mm (1/8" headphone jack size) stereo connectors. It's fairly straight forward, you'll commonly need these to connect two audio devices together. Cable is 6 ft long. In Stock [Buy Now](https://www.adafruit.com/product/876) [Related Guides to the Product](https://learn.adafruit.com/products/876/guides) ![Stereo 3.5mm Plug/Plug Audio Cable](https://cdn-shop.adafruit.com/640x480/876-01.jpg) # Trellis M4 Beat Sequencers ## Eight-Step Drummer https://youtu.be/0r35rKVCLrM This sequencer is perfect for getting started! It's a lot of fun to play, and very intuitive, since all four sample tracks are displayed continuously. No "menu-diving" allowed! You'll program it with CircuitPython, so first, let's prep the board for that. ## CircuitPython Prep To prep the Trellis M4 to run the sequencer code, follow these steps: - Update the [bootloader for NeoTrellis ](https://learn.adafruit.com/adafruit-neotrellis-m4/update-the-uf2-bootloader)from the Trellis M4 guide - Install the [latest CircuitPython for NeoTrellis ](https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython)from the Trellis M4 guide - Get the [latest CircuitPython library pack](https://github.com/adafruit/Adafruit_CircuitPython_Bundle/releases/), matching the version number with the major version of CircuitPython you are using, unzip it, and drag the libraries you need over into the **/lib** folder on **CIRCUITPY**. The latest library package includes support for Trellis M4. [https://github.com/adafruit/Adafruit\_CircuitPython\_Bundle/releases/](https://github.com/adafruit/Adafruit_CircuitPython_Bundle/releases/) ![](https://cdn-learn.adafruit.com/assets/assets/000/065/972/medium800/feather_circuitpython_Screen_Shot_2018-11-09_at_7.14.24_PM_copy.png?1542327781) If you'd like to reduce the storage footprint of the **li**** b** folder (to make room for lots of sound files!) these are the only one's you'll need to keep, you can remove the rest: - **adafruit\_trellism4.mpy** - **adafruit\_fancyled** folder - **neopixel.mpy** - **adafruit\_matrixkeypad.mpy** - **adafruit\_adxl34x.mpy** - **adafruit\_bus\_device** ## Prepare Audio Files Audio files can be gathered by any means you like, but they will all need to be formatted the same way to be recognized by the Trellis M4. [See this guide on how to convert audio files](https://learn.adafruit.com/microcontroller-compatible-audio-file-conversion/check-your-files).  For the Eight-Step Simple Sequencer you can use either mono or stereo files, just make sure all of your files are the same format, no mixing and matching! Info: ## Sound Packs For your convenience and drumming pleasure, we've compiled some sound kits for you to use. Simply download this zip file, uncompress it, and you'll be able to use them on the board after copying and renaming them as outlined below. [sound_packs.zip](https://cdn-learn.adafruit.com/assets/assets/000/066/017/original/sound_packs.zip?1542348728) ## Samples Directory With your Trellis M4 plugged into your computer, it will show up as the **CIRCUITPY** USB drive. Open it up and create a new folder named `samples` ![](https://cdn-learn.adafruit.com/assets/assets/000/065/974/medium800/feather_folders.jpg?1542329377) ## Copy Sounds Copy a set of four sound files from one of the packs and paste it into the `samples` folder you just made on the Trellis M4's CIRCUITPY drive. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/018/medium800/feather_sounddrag.jpg?1542348881) ## Rename Rename the four files like this: - **drum\_cymbal\_pedal.wav** to **voice01.wav** - **drum\_snare\_hard.wav** to **voice02.wav** - **elec\_ping.wav** to **voice03.wav** - **bd\_haus.wav** to **voice04.wav** As you'll see in the code below, this name pattern: `/samples/voice01.wav` through `/samples/voice04.wav`is the only set of names that will be found and played. ![](https://cdn-learn.adafruit.com/assets/assets/000/065/976/medium800/feather_rename.png?1542329802) When we code the Trellis M4 with the sequencer program, the voices (sound files) will be arrayed along the four rows as shown here. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/016/medium800/feather_eightStepChar_voices.jpg?1542340071) ## CircuitPython Code Everything is now prepared, you just need the actual code! Copy the code shown here, and then paste it into Mu. Save it to your Trellis M4 as **code.py** https://github.com/adafruit/Adafruit_Learning_System_Guides/blob/main/NeoTrellis/NeoTrellis_M4_Simple_Drum_Machine/code.py ## Sequence Tracking Bar When the board restarts, it will play through all four sound files, and then start running the sequence tracking bar forward ![](https://cdn-learn.adafruit.com/assets/assets/000/066/009/medium800thumb/feather_eightStepChart_01.jpg?1542338669) There are many ways to conceptualize an eight step sequence. I like to think of it as a single measure with 4/4 timing, meaning there are four beats to the measure and a quarter note gets the beat. So, our seqeunce is made of eight eighth notes, and the steps can be counted as: **"one-and-two-and-three-and-four-and"** ![](https://cdn-learn.adafruit.com/assets/assets/000/066/010/medium800thumb/feather_eightStepChart_01_text.jpg?1542338702) ## Program Beat Patterns Now, you can start making up some beats using the samples! ## Kick Try pressing the first and fifth buttons on the bottom row to start up a kick drum on the first and third beats of the measure (remember, there's a beat on every other button pad, with syncopated subdivision between them). ![](https://cdn-learn.adafruit.com/assets/assets/000/066/011/medium800thumb/feather_eightStepChart_02.jpg?1542338718) ## Snare Now we'll add in a snare on step 3 and 8, which are the second beat and the "and" after the fourth beat as shown here. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/012/medium800thumb/feather_eightStepChart_03.jpg?1542338750) ## Hi-Hats Now let's lay in hi-hats on nearly every beat, as shown. While the Trellis M4 can play multiple sounds simultaneously, sometimes patterns sound nicer when there isn't too much going on on every step! ![](https://cdn-learn.adafruit.com/assets/assets/000/066/013/medium800thumb/feather_eightStepChart_04.jpg?1542338768) ## "Cowbell" Lastly, we'll throw in an electronic blip sound that's reminiscent of the "cowbell" on a Roland TR-808. We'll put it on the two and then on the eighth note divisions of the three and four. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/014/medium800thumb/feather_eightStepChart_05.jpg?1542338786) Here is what the sequence sounds like with the 808 style voices: https://youtu.be/0r35rKVCLrM And here it is at a higher BPM with some genuine Adafruit warehouse sounds! You can increase and decrease the tempo just by tilting the Trellis M4 to the right or left. The Analog Devices ADXL343 accelerometer built right on the board detects the rotation and the CircuitPython code translates that data into tempo changes. https://youtu.be/lvWizG4zWsE # Trellis M4 Beat Sequencers ## Sixteen-Step Seqeuncer/Sampler ![](https://cdn-learn.adafruit.com/assets/assets/000/066/041/medium800/feather_sixteen_step_seq_labels.png?1542388348) This is a more fully featured sequencer, plus, it's a live sampler! It is a 16-step drum and voice/recording sequencer with eight built-in drum samples and eight slots for recording fresh, live samples through a plugged-in microphone. Here are the key features: - Sixteen step sequencer - Two banks of eight sounds: a built-in drum kit and a sampled kit of your own devising! - Step muting - Beat repeats - Tilt (accelerometer) effects - Bank soloing - Tempo up/down - Volume up/down - Endless fun! ## Usage Overview This will give you an idea of general usage, and then we'll go into more details and examples below. You can create your own drum patterns by selecting one of the **kit** sounds and then, in **write** mode,  "placing" that sound into any of the 16 **sequence steps.** You can repeat this with all of the different sounds you want to use, and multiple sounds can be played from the same **sequence step**. Hit **play** at any time to hear your beats played over a set of headphones or powered speakers! You can even edit the pattern while playing, or, switch out of **write** mode and play live fills on top of the sequence. You can add interest to your patterns by triggering three types of **beat repeats,** or, layer on some **tilt effects** that can be adjusted by simply tilting the Trellis M4 from side to side! Each of the two banks of kit sounds can be solo'd, there are buttons to adjust tempo and volume, and you can mute any step in the sequence in real time during playback for breakdowns and build ups! ## Firmware All you need to do to use this sequencer on your Trellis M4 is to plug it into USB, download the firmware .uf2 file below, place your Trellis M4 into bootloader mode by double-clicking the reset button on the back, and drag the firmware file onto the **TRELSM4BOOT** drive that shows up. [sixteen_step_seq.uf2](https://cdn-learn.adafruit.com/assets/assets/000/080/830/original/sixteen_step_seq.uf2?1568313781) Warning: # Interface Tour Let's have a look at the interface of your sequencer. We use color coding to signify different groupings. The top two rows are the **sequence steps** , which have a couple of different uses we'll cover in a bit. The bottom two rows are broken up into the following groupings: - **edit** - **beat repeat** - **tilt effects** - **kit solo** - **tempo** - **volume** - **transport** Most buttons have a single use, which makes pretty easy to learn to program and play your beats, rather than having lots of "menu diving" and secret modes. That said, there are a few modes to enter using the **edit** buttons which will change the function of the **sequence step** buttons. We'll go over these in a moment. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/073/medium800/feather_sixteen_step_seq_usage_15.png?1542393560) ## Sounds There are two banks of sounds available for sequencing and live play. The top row is the **built-in kit** , which has the following: - **kick 1** - **kick 2** - **clap** - **crash** - **closed hi-hat** - **open hi-hat** - **rim** - **snare** The second row is the **sampled kit**. This is where you can record eight of your own samples using a microphone on a set of earbuds plugged into the stereo 1/8" (3.5mm) TRRS jack. ## Edit ### **Sound Select** Press and hold the **sound select** button to preview any **kit sound.** Try it now by holding **sound select** and then pressing button **2** to hear the **kick 2** drum. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/078/medium800/feather_preview_kick.jpg?1542395578) ### **Write Mode** Now, let's place the **kick 2** drum into some slots on the sequence. Press the **write mode** button, and you'll see the **sequence steps** lights turn off. This indicates that the currently selected kit sound is not assigned to any steps. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/093/medium800/feather_write_mode.jpg?1542401195) ### **Kick** Let's add the kick drum on the first and third beats of the pattern, as well as on anticipatory final step of the sequence to lead back into the next repeat. Primary: ![](https://cdn-learn.adafruit.com/assets/assets/000/066/092/medium800/feather_kicks.jpg?1542401002) ### **Fill out the Pattern** You can now fill out the pattern with more drums. To do so, repeat the process of holding **sound select** and pressing one of the **kit sounds.** Release the **sound select button** and then press the **sequence steps** where you want that sound to play. Note, you must be in **write mode** to place sounds in step slots, so check that that button is lit up. If not, press it! Info: ### **Snare** Here, I've added snares on the two and four of the count (steps 5 and 13 of the sequence). ![](https://cdn-learn.adafruit.com/assets/assets/000/066/091/medium800/feather_snares.jpg?1542400992) ### **Closed Hat** We'll add in closed hi-hats next. Notice how the currently button 5 lights up magenta since it is trying to be both blue to signify the currently selected sound as well as red to signify that it will play on the fifth step of the sequence. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/090/medium800/feather_closedhats.jpg?1542400984) ### **Open Hat** Place an open hat in sequence slot 14. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/089/medium800/feather_openhat.jpg?1542400977) ### **Clap** Finally, let's use the same method as before to add in a clap sound in sequence slots 2, 8, and 16. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/088/medium800/feather_clap.jpg?1542400828) ## Transport ### **Play** Time to listen to the beats! For safety, get out of **write mode** by toggling the **write mode button,** then, press the **play** button and the sequence will run and loop. ![](https://cdn-learn.adafruit.com/assets/assets/000/066/094/medium800thumb/feather_basic_playback.jpg?1542401883) https://youtu.be/raUvfpZg-Bo ### **Record** With a microphone plugged in, such as the inline mic on a set of earbuds, you can record your own samples to any slot in the second bank. Press and hold the **record** button, and then hold one of the buttons 9-16 while you sing, talk, scream, beat box, squawk, or otherwise make beautiful sounds. Release both buttons when you're finished. Each sample can be up to two seconds long. Now, you can select and sequence any of these **sampled-kit** sounds just as you did with the **built-in kit** sounds. ## Beat Repeats and Step Muting Once you've got a sequence playing, you can have fun altering it during performances by using the **beat repeat** buttons. Press and hold **stutter** to create a fast, repeating division of the current beat you're. The **fast stutter** works the same, only with an even higher division level. **Jump** works a little differently. Hold the **jump** button and then while it's held, press any one of the sixteen **sequence step** buttons to instantly jump back to that beat. A related technique is **step muting.** Press any of the sequence step buttons to toggle muting for all sounds on that step. It's a fun way to breakdown or build up your pattern. This video shows some **beat repeat** effects at work, followed by **step muting.** Warning: https://youtu.be/g3wanQSbSAg?t=22 ## Tilt Effects You can also create interest by adding and tuning the filter and bit crush effects. The **low pass filter**  (LPF) cuts out higher frequencies (only allowing low frequencies to pass through, hence the name) while the **high pass filter** (HPF) cuts out lower frequencies. Press either button and then tilt the Trellis M4 side to side. This changes the cuttoff frequency of the filter and sounds totally awesome. https://youtu.be/q8qx50_oCQA You can also crush the playback sample bit rate with the **bit crush** effect, and dial it in with the tilting action as well. https://youtu.be/9KLWlxaui5o ## Kit Solo The next grouping are the **solo** buttons. Pressing either or both of these allows you to cut an entire sound bank in and out during playback, effectively muting either all of the built-in kit sounds or any recorded samples. https://youtu.be/xOTBNUdZOE4 ## Tempo You can adjust the tempo in increments of two BPM faster or slower by pressing the **tempo up** or **tempo down** button. This is great for fine tuning your tempo -- if you want to make bigger changes, press and hold one of the buttons to increase/decrease constantly until you arrive at your tempo destination! https://youtu.be/yFmM_J7YGmU ## Volume Tap the **volume up** or **volume down** buttons to adjust the output loudness. ## Inspiration There are lots of great resources for 16-step drum patterns, have a[look online for some](https://subaqueousmusic.com/drum-patterns-for-electronic-music/). ## Deeper Modification For advanced synth hackers, if you want to tweak the Arduino code driving this thing, you can [head to the GitHub repo](https://github.com/adafruit/Adafruit_NeoTrellisM4/tree/master/examples/sixteen_step_sequencer) to have a look! # Trellis M4 Beat Sequencers ## FAQ/Troubleshooting ### If your NeoTrellis M4 is powered by your computer USB, first thing to try is decoupling any ground loops by using headphones or a powered speaker running from a battery pack. If it persists, there's a chance you're hearing serial data being transferred over the USB port, which can be noisy. This is the trade off of going with plain DAC output as opposed to I2S. It is meant to be a simple audio playback toy, not audiophile quality :) You may also want to try powering the NeoTrellis M4 over a USB battery pack instead of your computer.   ### The 16-step sequencer 'sampler' demo where you can record audio onto the board depends on audio being stored in the flash memory, which is **also** where circuitpython stores files, so if you play one of the 'prerecorded' audio clips it will play files on the file system! You can solve this by loading CircuitPython back onto the board, then removing all the WAV files. ### Some computers, especially Mac's, will write a small amount of data after a few seconds, this causes CircuitPython to (correctly) reboot, and you'll get the audio re-start after a few seconds. ### Correct, these are **Arduino** programs. Once you're done with these examples, [re-visit the CircuitPython for NeoTrellis M4 installation page and re-install CircuitPython](https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython) ### You're hearing the output capacitors discharge after not playing audio for a while. This normal, not harmful, and occurs with some headphones/speakers ### It's possible to accidentally "press" a column of four buttons even when you intend to only press one. This can happen when you press a button at an angle other than straight down on top of the button pad. The elastomer conductive part touches the NeoPixel ground pin against the column which makes the chip think the whole row/column is pressed. It only happens on _some_ buttons and _some_ angles, and is not common It's not harmful, and there's a few ways to avoid it: - Press straight down on buttons not at an angle - Cut a thicker top panel from wood/plastic/3D printing so that the buttons cannot be pressed at an angle - Read buttons via the [https://github.com/adafruit/Adafruit\_NeoTrellisM4](https://github.com/adafruit/Adafruit_NeoTrellisM4) library which will do a software filtering to remove the duplicate button presses ### If many of the NeoPixels are at close to full brightness, you will draw too much power from the USB port on your computer. Try lowering the brightness. If you are using the `adafruit_trellism4` library, you can use the `.brightness` setter to lower the brightness (1.0 is max; try 0.2 or 0.3). ## 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...** In Stock [Buy Now](https://www.adafruit.com/product/4020) [Related Guides to the Product](https://learn.adafruit.com/products/4020/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... Out of 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... In 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,... In Stock [Buy Now](https://www.adafruit.com/product/1611) [Related Guides to the Product](https://learn.adafruit.com/products/1611/guides) ### USB Patterned Fabric Cable - A/MicroB [USB Patterned Fabric Cable - A/MicroB](https://www.adafruit.com/product/2008) Oooh it's so soft! And that beautiful pattern! If you have to have visible cables then you might as well have the nicest fabric bound cable with a eye-catching snake-like pattern.  That's why we now carry this standard A to micro-B USB cable for USB 1.1 or 2.0.... No Longer Stocked [Buy Now](https://www.adafruit.com/product/2008) [Related Guides to the Product](https://learn.adafruit.com/products/2008/guides) ### Little Rubber Bumper Feet - Pack of 4 [Little Rubber Bumper Feet - Pack of 4](https://www.adafruit.com/product/550) Keep your electronics from going barefoot, give them little rubber feet! These small sticky bumpers are our favorite accessory for any electronic kit or device. They are sticky, but not impossible to remove. They're small enough to fit onto any board, and have just enough height to give... In Stock [Buy Now](https://www.adafruit.com/product/550) [Related Guides to the Product](https://learn.adafruit.com/products/550/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) ### 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) ## Related Guides - [Adafruit NeoTrellis M4 Express](https://learn.adafruit.com/adafruit-neotrellis-m4.md) - [ABC Soundboards with NeoTrellis](https://learn.adafruit.com/abc-soundboards-with-neotrellis.md) - [Bringing Back THE VOICE of Speak & Spell](https://learn.adafruit.com/bringing-back-the-voice-of-speak-spell.md) - [Star Trek Soundboard with NeoTrellis](https://learn.adafruit.com/star-trek-sound-board-with-neotrellism4.md) - [Mini UNTZtrument: 3D Printed MIDI Controller](https://learn.adafruit.com/mini-untztrument-3d-printed-midi-controller.md) - [NeoTrellis M4 Animated Dice Roller](https://learn.adafruit.com/neotrellis-dice.md) - [What is Web MIDI & BLE MIDI?](https://learn.adafruit.com/web-ble-midi.md) - [Mu Keyboard Shortcut Cheat Sheets](https://learn.adafruit.com/mu-keyboard-shortcut-cheat-sheets.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 Live Launcher](https://learn.adafruit.com/neotrellis-live-launcher.md) - [Trellis 3D Printed Enclosure](https://learn.adafruit.com/trellis-3d-printed-enclosure.md) - [Adafruit MagTag COVID Vaccination Percent Tracker](https://learn.adafruit.com/adafruit-magtag-covid-vaccination-percent-tracker.md) - [DIY IoT Doorbell Camera with MEMENTO](https://learn.adafruit.com/diy-iot-doorbell-camera-with-memento.md) - [Light Up Prop with Prop-Maker](https://learn.adafruit.com/prop-maker-light-wand.md)