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Reverse Engineering the this.is.NOISE Gamma

Welcome to the documentation and agent skills reference for the this.is.NOISE Gamma Mini Synth reverse-engineering initiative.

This project reverse-engineers the hardware pinout, interfaces, and peripherals of the Gamma synthesizer in order to build an open-source Board Support Package (BSP) and support custom embedded firmware development.

The Gamma synth is powered by an embedded Electro-Smith Daisy Seed 2 DFM (ARM Cortex-M7 @ 480 MHz, STM32H750IBK6, PCM3060 stereo audio codec).

Hardware Architecture

flowchart TD
    subgraph Panel ["Gamma Front Panel"]
        K["4 Potentiometers (Knobs)<br>Chord/Notes Vol & Filter<br>ADC1"]
        J["2 Dual-Axis Joysticks<br>Pitch, Res, Mod, Pan<br>ADC1"]
        SW["14 Tactile Switches<br>7 Note Keys + 7 Chord Keys<br>Discrete GPIO Pull-Up"]
        ENC["Rotary Encoder + Push Button<br>Quadrature Gray Code & Select<br>GPIO TIM ISR"]
        OLED["1.3-inch 128x64 OLED Display<br>SSD1306 Controller<br>I2C1 @ 0x3D"]
    end

    subgraph Core ["Daisy Seed 2 DFM Core"]
        MCU["STM32H750IBK6 (ARM Cortex-M7 @ 480 MHz)<br>128 KB Internal Flash | 1 MB RAM<br>64 MB QSPI Flash | AXI SRAM"]
        CODEC["TI PCM3060 Stereo Codec<br>24-bit / 48 kHz<br>SAI1 Audio Engine"]
        USB["USB-C Interface (External HS FS)<br>DFU Flashing | CDC Serial | USB MIDI"]
    end

    subgraph Output ["Audio Output"]
        HP["3.5mm Stereo Headphone Output"]
        AMP["Stereo Class-D Amplifier<br>Mute Control (seed::D32 / PC3)"]
        SPK["Stereo Case Speakers"]
    end

    K -->|Analog Channels| MCU
    J -->|Analog Channels| MCU
    SW -->|Active-Low GPIO| MCU
    ENC -->|Quadrature Signals| MCU
    MCU -->|I2C 1 MHz| OLED
    MCU ---|SAI1 Stereo Audio| CODEC
    MCU ---|USB-C Interface| USB
    CODEC --> HP
    CODEC --> AMP
    AMP --> SPK

Hardware Specifications

Component Specification Description & Mapping
Microcontroller STM32H750IBK6 ARM Cortex-M7 running at 480 MHz with DSP and FPU
System Memory 1 MB RAM AXI SRAM (0x24000000), DTCM (0x20000000), SRAM1 DMA buffers
Storage 64 MB QSPI Flash External QSPI flash memory (0x90040000) for application binaries
Audio Codec Texas Instruments PCM3060 24-bit stereo audio codec running via SAI1 @ 48 kHz
Display 1.3" Monochrome OLED 128x64 pixels, SSD1306 controller via I2C1 (seed::D11/seed::D12) at 0x3D
Note Keys 7 Discrete Tactile Switches N1–N7 on seed::D1–D7 (PC11, PC10, PC9, PC8, PD2, PC12, PG10)
Chord Keys 7 Discrete Tactile Switches C1–C7 on seed::D8–D10, D13, D14, D26, D27
Potentiometers 4 Analog Knobs 10k linear pots on seed::D17, D18, D19, D20 (ADC1, software inverted)
Joysticks 2 Dual-Axis Analog Sticks Left (Pitch/Resonance) and Right (Mod/Pan) on seed::D21–D24
Rotary Encoder Quadrature Encoder + Push 4 transitions/detent on seed::D15, D16 with push switch on seed::D28
Speaker Amplifier Stereo Class-D Amp Case speakers with hardware enable/mute line on seed::D32 (PC3)
USB Connectivity External USB-C (USB_OTG_HS) Full Speed DFU flashing, USB CDC logging (seed::D29/seed::D30), and USB MIDI

Documentation Sections

Explore the key sections of this documentation suite: