26.2 zicModSamples

An 8-track PCM sample drum machine and 16-step sequencer designed for the LilyGO T-Display-S3 (ESP32-S3) and Linux Desktop. Designed to sync seamlessly alongside zicModKick.

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Features

• 8 Sample Playback Tracks:
  • Snare, Clap, HatCl, HatOp, Perc1, Perc2, Tom, FX.
  • Zero-latency 16-bit mono 22.05 kHz PCM sample player with pitch shifting (-12..+12 semitones) and volume controls.
• 16-Step Pattern Sequencer:
  • Independent 16-step patterns for each of the 8 tracks.
  • Smooth Mute / Unmute: Muting stops new step triggers while allowing active sound release tails to decay down to silence.
  • Algorithmic drum pattern generator.
• MIDI Clock Synchronization & Auto-Fallback:
  • Receives real-time 24 PPQN MIDI Clock (0xF8), Start (0xFA), and Stop (0xFC) on GPIO 16 via direct 3.3V serial link from zicModKick.
  • Automatic Clock Fallback: If no external MIDI clock pulse is detected for 500 ms, zicModSamples automatically switches back to its internal BPM clock without interrupting audio playback.
• 320x170 Horizontal Display & Touch Gestures:
  • Slide/Swipe left or right with your finger (or mouse drag on desktop simulator) to switch views:
    1. Overview & Mute Grid: Live step playhead progress, 8-track mute buttons, track selection.
    2. 16-Step Sequencer: Interactive step grid for toggling steps of the active track.
    3. Sample Editor: Real-time sample selection, pitch shifting (-12..+12 ST), and volume controls.
    4. Global Settings: Play/Pause toggle, BPM adjustment, pattern generator.
• NeoTrellis Keypad & Keyboard Mappings:
  • 16 physical buttons (4x4 matrix). On desktop simulator, mapped to PC keyboard keys:

    1  2  3  4  -> Pads 0,  1,  2,  3
    q  w  e  r  -> Pads 4,  5,  6,  7
    a  s  d  f  -> Pads 8,  9, 10, 11
    z  x  c  v  -> Pads 12, 13, 14, 15
    

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Hardware & Pin Layout (LilyGO T-Display-S3)

Component	Description	Pin / Location
Microcontroller	LilyGO T-Display-S3 (ESP32-S3 Dual Core @ 240MHz)	Core Processor
Internal MIDI Link	Hardware Serial 1 RX (31,250 baud)	GPIO 16 (Direct wire from Daisy Seed D13)
Audio Output	Single-pin PDM I2S Audio Output	GPIO 1
Display	ST7789 320x170 Color LCD Display	Pins 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 38, 39
Touch Screen	CST816S Capacitive Touch	SDA: GPIO 18, SCL: GPIO 17, RST: GPIO 21
NeoTrellis Keypad	Adafruit NeoTrellis 4x4 Keypad	I2C Addr 0x2E (Shared SDA 18 / SCL 17)
Power Supply	Common +5V Rail & Ground	5V/VIN and GND

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Inter-Board Connection Diagram (zicModKick $\rightarrow$ zicModSamples)

+------------------------------------+          +-----------------------------------+
|      Daisy Seed (zicModKick)       |          |   LilyGO ESP32 (zicModSamples)    |
|                                    |          |                                   |
|   D6 (UART5 TX)  --> [Front Jack]  |          |                                   |
|   D13 (USART1 TX)---------------------------->| GPIO 16 (Serial1 RX)              |
|   VIN (5V)       <--- 5V Power ---><----------| 5V / VIN                          |
|   GND            <--- Common GND --><---------| GND                               |
+------------------------------------+          +-----------------------------------+

• Direct 3.3V Connection: No optocoupler or level shifter is needed since both chips share a common ground and run at 3.3V logic.
• Seamless Sync: zicModKick acts as master clock transmitter; zicModSamples locks tempo automatically upon receiving clock bytes, and seamlessly falls back to internal tempo when un-plugged or stopped.

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Desktop Simulator (SFML + ALSA)

Build & Run

From the repository root:

make -C zicModSamples

Or explicitly build:

make -C zicModSamples build_zic

Run the compiled desktop executable:

make -C zicModSamples run

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LilyGO T-Display-S3 Firmware Setup

Flashing with PlatformIO

1. Connect your LilyGO T-Display-S3 board via USB-C.
2. Build and upload using make:

make -C zicModSamples up

or:

make -C zicModSamples esp32

3. Convert audio samples:

make -C zicModSamples samples

4. Open serial monitor (optional):

pio device monitor -d zicModSamples/esp32