Hardware Design

Portable music instrument with location-aware sampling, synthesis, and AI composition

Technical Specifications

Audio Engine

  • Sample Rate: 44.1kHz
  • Bit Depth: 24-bit
  • Latency: <10ms
  • 8 Sample Slots (30s each)
  • 8-Track Step Sequencer
  • 3 Effect Types (Delay, Glitch, Grain)

Inputs

  • Stereo Line In (3.5mm TRS)
  • Microphone In (3.5mm TRS)
  • MIDI In (TRS-A)
  • USB-C (Data + Power)
  • GPS Antenna (internal)

Outputs

  • Stereo Main Out (3.5mm TRS)
  • Headphone Out (3.5mm TRS)
  • MIDI Out (TRS-A)
  • USB Audio (Class Compliant)

Controls

  • 8x Touch Pads (MPR121)
  • 5x Main Encoders (VOL/PAN/FILT/FX/DECAY)
  • 4x Synth Encoders (CUTOFF/RES/ATK/REL)
  • 4x FX Encoders (DELAY/GLITCH/GRAIN/CRUSH)
  • 4x Mixer Faders (MIC/SMP/SYN/RAD)
  • 1x Crossfader (Scene A/B)
  • 3x Transport Buttons (Play/Stop/Rec)
  • 4x Mode Buttons
  • 4x Nav Buttons (MENU/BACK/SHIFT/PAGE)
  • 5x Function Buttons (DUB/FILL/CLR/SCENE/BANK)
  • 5-Way Joystick + PREV/NEXT
  • 13 encoders via 2x MCP23017 I2C expanders

Connectivity

  • WiFi 802.11 b/g/n
  • Bluetooth 4.2
  • GPS (NEO-6M)
  • AI API (Claude)

Physical

  • Size: 300 x 200 x 50mm
  • Weight: ~800g
  • Display: 2.8" ILI9341 TFT (320x240, SPI DMA)
  • Battery: 3-4 hours (3500mAh)

Teensy 4.1 Pin Assignments

FunctionPinsProtocolNotes
Audio Shield (I2S)2, 7, 20, 21, 23I2SSGTL5000 codec (RESERVED)
Touch Sensor (CAP1188)16, 17I2C1Address: 0x29 on Wire1
2.8" ILI9341 LCD10, 11, 12, 13, 9, 15SPICS=10, DC=9, RST=15 (DMA)
Buttons (direct)2, 3, 4, 5GPIOMODE, SHIFT, REC, PLAY
NeoPixel LEDs6WS28128x RGB (470Ω series)
ESP32-S20, 1UARTSerial1 @ 115200
MCP23017 ×216, 17I2C10x20 + 0x21 on Wire1 (encoders + nav)
GPS (PA1010D)18, 19I2CAddress: 0x10 on Wire
ADS1115 ADC18, 19I2CAddress: 0x48 on Wire (faders)
SD CardBuilt-inSDIO64GB for samples

Bill of Materials v3.2 — Actual Hardware Received

Verified March 2026 — 3 orders from Antratek (BE), Diotronic (BCN), Adafruit (US)

#ComponentSourceQtyPrice
PROCESSORS & AUDIO
1Teensy 4.1 w/pins (600MHz Cortex-M7)Antratek1€42.96
2Audio Shield Rev D2 (SGTL5000 codec)Antratek1€11.85
3SparkFun ESP32-S2 Thing Plus (WiFi)Antratek1€18.09
4microSD Card 32GB (SanDisk Ultra)1
5Teensy 4.1 w/pins (backup)Adafruit1$31.50
6Audio Shield Rev D (backup)Adafruit1$9.95
DISPLAY
72.8" ILI9341 TFT LCD w/touch (P1770)Adafruit1$39.95
8OLED SSD1306 0.96" I2CDiotronic1
USER INTERFACE
9CAP1188 8-ch capacitive touch (P1602)Adafruit1$7.95
10Copper tape 5mm × 25m (touch pads)Diotronic1
11Rotary encoder EC11 w/push switchDiotronic7
12Rainbow Micro Knobs 10-pack (P5542)Adafruit2$9.90
13Slide pot 45mm B10K (P4272)Adafruit5$12.50
14Tactile button 6×5mm DTS61NDiotronic16
155-way navigation switch (P504)Adafruit1$2.50
16WS2812B 8-LED NeoPixel stripDiotronic1
CONNECTIVITY & SENSING
17GPS PA1010D STEMMA QT (P4415)Adafruit1$29.95
18ADS1115 16-bit ADC 4-ch (P1085)Adafruit1$14.95
19MCP23017 I/O expander DIP-28 (P732)Adafruit2$5.00
20Audio jack 3.5mm stereo chassisDiotronic3
PROTOTYPING & WIRING
21Breadboard 830ptsDiotronic2
22Jumper wires 140pcDiotronic2
23Pin header male 40-pinDiotronic3
24Pin header female 40-pinDiotronic3
2528-pin DIP IC socketDiotronic2
26Resistor 10K 1/4WDiotronic20
27Capacitor 100nF ceramicDiotronic10
28Capacitor 10µF electrolyticDiotronic5
29Wire kit 22AWG (P3174)Adafruit1$15.95
30Soldering station 48WDiotronic1
31Solder wire 1mm 100g + flux pasteDiotronic1
32Helping third hand (P291)Adafruit1$6.00
FUTURE / SET ASIDE
33RFM95W LoRa 900MHz (P3072)Adafruit1
34KB2040 (P5302)Adafruit1
35USB Type C Plug + Vertical PortAdafruit2
ANTRATEK (Belgium, Jan 2026)€78.05
DIOTRONIC (Barcelona, Feb 2026)~€80
ADAFRUIT (US, Mar 2026)~$194

USB-powered prototype — battery system deferred to portable phase. Still needed: 6× EC11 encoders, 2.2KΩ ×4, 1KΩ ×5, 470Ω ×1 resistors (next Diotronic visit).