Sixteen-Step Seqeuncer/Sampler

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.

This program will replace CircuitPython, to get back to your CircuitPython projects, reinstall it by following https://learn.adafruit.com/adafruit-neotrellis-m4/circuitpython

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.

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.

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.

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.

You can think of this 16-step pattern as one 4/4 time measure counted as "one ee and uh two ee and uh three ee and uh four ee and uh"

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!

Notice how the currently slected sound is lit up blue when you're in write mode so you know which sound you're placing in the seqeunce step slots.

Snare

Here, I've added snares on the two and four of the count (steps 5 and 13 of the sequence).

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.

Open Hat

Place an open hat in sequence slot 14.

Clap

Finally, let's use the same method as before to add in a clap sound in sequence slots 2, 8, and 16.

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.

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.

Note some videos were shot with a modified wooden faceplate. You can make your own case mods using the Trellis M4 CAD files found here: https://github.com/adafruit/Adafruit-NeoTrellis-M4-PCB-and-Enclosure

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.

You can also crush the playback sample bit rate with the bit crush effect, and dial it in with the tilting action as well.

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.

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!

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.

Deeper Modification

For advanced synth hackers, if you want to tweak the Arduino code driving this thing, you can head to the GitHub repo to have a look!

This guide was first published on Nov 18, 2018. It was last updated on Nov 18, 2018. This page (Sixteen-Step Seqeuncer/Sampler) was last updated on Dec 05, 2019.