• Non-Volatile Storage: It provides non-volatile storage, meaning that it retains data even when the power is turned off. This feature is crucial for storing firmware, user settings, and other data that need to be preserved across device reboots or power cycles.
• Serial Interface: It uses a serial interface (often SPI - Serial Peripheral Interface), which allows it to communicate efficiently with microcontrollers and other devices using fewer pins compared to parallel interfaces.
• High Density: With a storage capacity of 32 megabits, it can store a substantial amount of data, suitable for various applications needing moderate data storage.
• Sector Erase: The memory supports sector or block erase operations, providing flexibility for rewriting specific sections of memory without affecting others.
• Low Power Consumption: Typically, such devices are designed to be power-efficient, making them suitable for battery-powered applications.
• Usage in Projects like Yours: In your Pico Macro Keyboard project, it could be used to store user-defined macros, keymaps, custom configurations, or even firmware binaries.

1. Impedance Matching: It helps match the characteristic impedance of the USB data lines to minimize reflections and ensure signal integrity.
2. Current Limiting: It can limit the current flowing through the data lines to protect the device from high currents, especially during hot-plug events.
3. Signal Conditioning: It can help in conditioning signals by providing the necessary resistance to ensure proper signal levels for the USB interface.

• Mechanical switches with per-key RGB lighting.
• Two rotary encoders for additional functionality.
• A modular 4-layer PCB design.
• Fully customizable keymaps catered to productivity, design, and gaming.

• Add new features or components?
• Change existing components or their connections?
• Improve the power distribution or layout?

1. Power and Ground Connections:
   • Connect the VDD and VSS pins of the N76E003 to the power supply and ground, respectively.
2. Programming Interface:
   • Ensure you have connections for programming the microcontroller. Typically, this involves the pins for Reset, Clock, and Data.
3. Communication Interfaces:
   • If you plan to use I2C, SPI, or UART, connect the relevant pins to the devices you want to communicate with.
4. GPIO Connections:
   • Decide which GPIO pins you need for interaction with sensors, switches, or other peripherals, and connect them accordingly.
5. Peripheral Connections:
   • Connect any additional peripherals you plan to use (e.g., LEDs, displays) to the appropriate pins on the N76E003.
6. Checking Compatibility:
   • Ensure the voltage levels and protocols are compatible with the Raspberry Pi Pico and other components.

1. Power and Ground:
   • Connect N76E003:VDD to +3V3:P1.
   • Connect N76E003:VSS to GND.
2. Programming Interface:
   • Connect appropriate programming pins (RST, data, and clock) to a programming header or provide test points.
3. Oscillator:
   • Connect an external crystal oscillator if precision timing is required, or configure for internal RC oscillator usage.
4. Additional Decoupling Capacitors:
   • Add capacitors for decoupling between N76E003:VDD and GND.

• Power:
  • N76E003:VDD to +3V3:P1
  • N76E003:VSS to GND
• Basic Components:
  • Add a 0.1uF decoupling capacitor between N76E003:VDD and GND.

1. Choose a header designator:
   • Let’s use J2 as the designator for this header.
2. Connect Pins:
   • Connect N76E003:RST to J2:1 $($Programming Header Pin 1 for Reset$)$.
   • Connect N76E003:DATA to J2:2 $($Programming Header Pin 2 for Data$)$.
   • Connect N76E003:CLK to J2:3 $($Programming Header Pin 3 for Clock$)$.
   • Connect GND to J2:4 $($Programming Header Pin 4$)$.
   • Connect +3V3 to J2:5 $($Programming Header Pin 5 for VCC$)$.

• Programming Connections:
  • Connect N76E003:RST to J2:1.
  • Connect N76E003:DATA to J2:2.
  • Connect N76E003:CLK to J2:3.
  • Connect GND to J2:4.
  • Connect +3V3:P1 to J2:5.

1. Decoupling/BYPASS Capacitor: It could serve as a decoupling capacitor near an integrated circuit to provide a local energy reservoir. This helps filter out noise or voltage spikes in the power supply, thereby stabilizing the voltage supplied to the IC.
2. Energy Storage or Smoothing: It might help smooth out voltage fluctuations in the circuit by storing and releasing charge as needed, particularly in circuits with loads varying over time.

• Raspberry Pi Pico 2: Serves as the main microcontroller, providing processing capabilities for handling inputs and outputs.
• Mechanical Switches: Used for tactile feedback, these are customizable keys that users can press to execute macros or perform specific functions.
• Per-Key RGB Lighting: Utilizes WS2812 LEDs for customizable lighting effects on each key, allowing users to personalize the appearance and feedback.
• Rotary Encoders: Two rotary encoders provide additional control options for precise adjustments or scrolling functionalities.
• 4-Layer PCB: The design incorporates a modular 4-layer PCB supporting complex routing and component placement, enhancing performance and reliability.
• Customizable Keymaps: Users can define their key mappings to suit different applications, increasing flexibility and utility for various software integrations.

• WS2812-2020: These are addressable RGB LEDs used for the per-key lighting.
• PEC12R-2220F-S0024 and EC12D1564402: These are rotary encoders allowing for rotary inputs and detecting the position changes.
• RT6150B-33GQW: Power management IC to regulate the voltage supply for the circuit.
• ABM8-272-T3: A 12 MHz crystal oscillator providing the clock for the microcontroller.
• 1N4007W and PMEG6010ELR: Diodes used for current regulation and protection circuits.
• Raspberry Pi RP2350A: At the core of the design is the RP2040 microcontroller from Raspberry Pi, featuring an array of GPIOs, ADCs, and communication interfaces.

• The design includes a power distribution network powered by USB Type-C, regulated by voltage regulators to provide necessary voltages to different components.
• RGB LEDs are daisy-chained with data input/output lines connecting the microcontroller to each LED's data in and out.
• Mechanical switches are organized in a matrix, reducing the number of GPIO pins needed to detect multiple key presses.
• Rotary encoders interface with the microcontroller through GPIO pins for sensing rotations.
• Various resistors and capacitors are included throughout the design for signal integrity and noise filtering.

graph TD;
    Pico[Pico Macro Keyboard]
    RaspberryPi["Raspberry Pi Pico 2 (RP2350A)"]
    Switches["Mechanical Switches (Choc Red)"]
    RGB["Per-key RGB Lighting (WS2812-2020)"]
    Encoders["Rotary Encoders (PEC12R-2220F-S0024, EC12D1564402)"]
    TypeC["USB Connection (TYPE-C-31-M-12)"]
    Power["Power Management (RT6150B-33GQW)"]
    Flash["Flash Memory (W25Q32RVXHJQ)"]
    Crystal["12MHz Crystal (ABM8-272-T3)"]
    Diodes["Diodes (1N4007W, PMEG6010ELR)"]

    Pico --> RaspberryPi
    Pico --> Switches
    Pico --> RGB
    Pico --> Encoders
    Pico --> TypeC
    Pico --> Power
    Pico --> Flash
    Pico --> Crystal
    Pico --> Diodes

• Reverse Voltage Protection: Prevents damage to the circuit due to incorrect power supply polarity.
• Voltage Drop: Introduces a slight voltage drop in the forward direction, which in some designs can help regulate the supply voltage to ensure downstream components are not subjected to over-voltage conditions.

1. GPIO29_ADC3:
   • Function: This is a general-purpose input/output (GPIO) pin on the Raspberry Pi Pico 2. It can also function as an analog-to-digital converter (ADC) input for channel 3. It can be used for digital I/O or to read analog voltages.
   • Usage: If you're using it for ADC, connect analog signals here to be read by the microcontroller.
2. +3V3:
   • Function: This represents the +3.3V power net in the circuit.
   • Usage: It's used to supply power to various components that require a 3.3V power rail, such as the Raspberry Pi Pico, some sensors, and other ICs.
3. Q1 (DMG1012T):
   • Function: Q1 is a MOSFET transistor, likely used for switching or amplification purposes.
   • Usage: It could be used to control power to a component like an LED or motor, or to switch a high-speed signal.
4. C21:
   • Function: C21 is a capacitor with a capacitance of 1nF (nanoFarads).
   • Usage: Capacitors are often used for filtering, smoothing power supply lines, or coupling signals in AC applications.
5. R16:
   • Function: R16 is a resistor with a resistance of 100kΩ.
   • Usage: It could be used as a pull-up or pull-down resistor, for current limiting, or part of a voltage divider network.
6. VSYS:
   • Function: This represents the system supply voltage net, which is used to power the board or parts of it.
   • Usage: Typically, this would be the main power supply line that could get its voltage input from a USB or another power source like a battery.
7. R15:
   • Function: R15 is a resistor with a resistance of 1kΩ.
   • Usage: Similar to R16, it could be used in various applications like current limiting or in a bias network.
8. R17:
   • Function: R17 is another resistor with a resistance of 1kΩ.
   • Usage: Used similarly to R15, depending on the exact context in your circuit.

• Switching: It may be used to turn a part of the circuit on or off. This could be controlling power to a peripheral or part of the controller.
• Level Shifting: MOSFETs are sometimes used to shift voltage levels between different parts of a circuit, enabling communication between components operating at different voltage levels.
• Voltage Regulation: Although less common, MOSFETs can be part of a voltage regulation scheme.

• Gate Connection: Q1's gate (pin G) is connected to a net linked with multiple components, potentially signaling when to activate the switch. Understanding this control line helps define the conditions under which the MOSFET operates.
• Source/Drain Connections:
  • The source (Q1:S) is connected to a net involving several GPIOs, including one potentially related to the Raspberry Pi Pico.
  • The drain (Q1:D) connects to various resistors and capacitors, possibly indicating the output or controlled part of the circuit.

• Microcontroller: Uses the Raspberry Pi Pico 2 (RP2350A), which integrates GPIOs for interfacing with various components such as switches, rotary encoders, and peripherals.
• Lighting: Utilizes WS2812-2020 LEDs for per-key RGB lighting, controlled via a data line to create customizable lighting effects.
• Rotary Encoders: Includes two rotary encoders (PEC12R-2220F-S0024 and possibly EC12D1564402) for additional input and control options.
• Switches: Equips multiple mechanical switches (Choc Red from Kailh) to perform various macros or key bindings.
• Power Management: The circuit integrates power management using components like RT6150B-33GQW which facilitates regulation of voltage supply for the microcontroller and LEDs.
• Connectivity: Incorporates USB Type-C connectivity (TYPE-C-31-M-12) for interfacing with host devices.
• Memory: Features external flash memory (W25Q32RVXHJQ) for storing keymaps and configurations.
• Peripherals: Includes capacitors, resistors, diodes, and other passive components for noise suppression, signal conditioning, and effective operation of the circuit.
• Licensing: The project is shared under the Creative Commons license CC BY 4.0, allowing users to use and adapt the design with proper attribution.

• Raspberry Pi Pico 2: The microcontroller at the heart of this project, providing processing power and connectivity.
• Mechanical Switches with RGB Lighting: Allows for customizable control and aesthetic lighting effects, enhancing user interaction.
• Rotary Encoders: Two rotary encoders add additional functionality, likely for volume control or other customizable functions.
• Modular 4-layer PCB: Indicates a complex and layered design for reliable connectivity and flexibility.
• Fully Customizable Keymaps: Users can program the macro pad to perform specific actions or execute commands tailored to their needs.

• Mechanical Switches (Choc Red switches): These include various designators like $\text{SW11}$, $\text{SW12}$, etc.
• RGB LEDs (WS2812-2020): Components like $\text{U11}$, $\text{U8}$ offer RGB lighting for each key.
• Rotary Encoders: $\text{SW14}$ and $\text{SW15}$ provide knob controls for added input.
• USB Type-C Connector (TYPE-C-31-M-12): Used for connecting the macro pad to other devices.
• Diodes and Resistors: Numerous components such as $\text{1N4007W}$ diodes and resistors like $\text{R12}$ and $\text{R11}$ are featured to manage voltage and current flows.

• Voltage Regulators and Capacitors: Power is managed using components like $\text{RT6150B-33GQW}$ to ensure stable operation, alongside capacitors such as $\text{C1}$, and others for filtering and stabilization.

• The project is designed using PCB elements and nets to facilitate communication between components. Nets like GND and +3V3 represent common grounding and power distribution paths.

• Mechanical Switches with RGB Lighting: The keyboard uses mechanical switches that have per-key RGB lighting, allowing for colorful and customizable visual feedback.
• Rotary Encoders: Two rotary encoders are included for additional input functionality, providing the ability to control various software functions such as volume or scrolling.
• Modular 4-layer PCB: The design features a modular four-layer PCB, allowing for structural flexibility and potential expandability or customization.
• Customizable Keymaps: You can program the keymaps to fit personal preferences or software requirements, making it highly adaptable for different user needs like gaming, design, or general productivity.

• Raspberry Pi Pico 2: Serves as the core microcontroller of the macro keyboard, providing the necessary I/O and processing power.
• Mechanical Switches: Specifically, Kailh Choc Red switches are used, known for their tactile feedback and compact design.
• RGB LEDs: WS2812-2020 LEDs are used for per-key RGB lighting.
• Type-C USB Connector: TYPE-C-31-M-12 for connecting the device to a host computer.
• Rotary Encoders: PEC12R-2220F-S0024 and EC12D1564402 for the rotary functionality.
• Diodes and Other Components: Such as the 1N4007W diode for directionality in circuits, along with various resistors, capacitors, and inductors for filtering and signal conditioning.

• Design and Productivity: Offers customizable macro commands for design software like Adobe Photoshop, Illustrator, or Figma.
• Gaming: Can be used as a secondary keyboard for gamers to have additional customizable hotkeys.
• General Usage: Facilitates complex workflows that involve repetitive tasks which can be automated with macros.

• Raspberry Pi Pico 2: This microcontroller serves as the main processing unit, allowing for customizable keymaps and seamless integration with software.
• Mechanical Switches: The project uses various Kailh Choc Red mechanical switches (e.g., SW11, SW5), which provide tactile feedback.
• Per-Key RGB Lighting: Utilizes WS2812-2020 LEDs (e.g., U11) for dynamic lighting on each key.
• Rotary Encoders: Two rotary encoders are included for added controls, such as volume adjustment or scrolling.
• Modular 4-layer PCB: Designed to be compact yet robust, allowing for easy customization and upgrades.

• Capacitors (e.g., C1, C17): Used for voltage stabilization and noise filtering in the circuit, with various capacitances (e.g., 0.1µF, 47µF).
• Resistors (e.g., R12, R18): Used for current limiting and voltage division, with resistances ranging from 1Ω to 100kΩ.
• Diodes (e.g., D10, D4): Primarily used for rectification and protection in the circuit. The 1N4007W diode is a common choice.
• Connectors (e.g., J1): Includes a USB Type-C connector for power and data transfer.
• Inductors (e.g., L1): Used in the power supply section to filter noise and maintain stable voltage outputs.

• USB Data Lines: Includes USB_DM and USB_DP nets for USB communication.
• GPIO Pins: Multiple GPIO pins from the Raspberry Pi Pico 2 are used for interfacing with switches, LEDs, and other peripherals.
• Power Nets: The project uses power nets like $+3V3$ and VSYS to distribute power across the PCB.

• Customizable Keymaps: Allows users to tailor key functions to their specific needs.
• Mechanical Switches: Equipped with Kailh Choc Red switches, offering tactile feedback.
• Per-key RGB Lighting: Uses $WS2812-2020$ LEDs for customizable lighting effects.
• Rotary Encoders: Two encoders ($PEC12R-2220F-S0024$ and $EC12D1564402$) provide additional input options.
• Power Management: Includes voltage regulation and power distribution using components like $RT6150B-33GQW$ for stable power supply.
• USB Connectivity: Uses a USB Type-C connector ($TYPE-C-31-M-12$) for modern connectivity options.
• 4-Layer PCB Design: Ensures compactness and efficient routing.

• Microcontroller: Raspberry Pi Pico 2 ($RP2350A$).
• Switches: Multiple Kailh Choc Red switches for tactile input.
• LEDs: WS2812 individually addressable RGB LEDs for lighting effects.
• Encoders: Rotary encoders for additional control options.
• Voltage Regulator: Ensures components receive stable voltage.
• USB Connector: For power and data communication with a computer.

• The keyboard is programmable, allowing for the assignment of macros and key functions, ideal for streamlining repetitive tasks or improving workflow efficiency.

• Memory Type: It's a non-volatile flash memory, meaning it retains data even when the power is turned off.
• Capacity: It provides 4 megabytes of storage, suitable for embedded applications that require a significant amount of data storage.
• Interface: The chip uses a Quad SPI (Serial Peripheral Interface) to communicate with a microcontroller. This interface allows for faster data transfer rates compared to traditional SPI.
• Package: This device comes in a small package, which helps in minimizing space on your PCB.

• Switching: The MOSFET can act as an electronic switch. It allows for the control of a large amount of current or voltage with a smaller control signal, which is useful in digital circuits to turn on or off large loads.
• Amplification: Although typically known for their switching capabilities, MOSFETs can also be used to amplify signals. This is less common in digital applications but possible in analog circuits.
• Voltage Control: The DMG1012T is likely used as a voltage-controlled switch. The gate (G) of the MOSFET is controlled by voltage from a microcontroller or other part of the circuitry. When the voltage at the gate exceeds a certain threshold, it allows current to flow between the drain (D) and source (S).

• Customizable Control: Allows users to define custom keymaps suitable for various software applications.
• Mechanical Switches: Uses mechanical switches for robust and tactile feedback.
• Per-Key RGB Lighting: Each key is equipped with RGB lighting, using WS2812 LEDs for dynamic visual effects.
• Rotary Encoders: Two rotary encoders are included for additional input methods, typically used for volume control or scrolling.
• Modular Design: Consists of a 4-layer PCB that supports modular configurations.

• Raspberry Pi Pico 2: Acts as the main microcontroller, interfacing with the keys and LEDs.
• WS2812 LEDs: Provide customizable RGB lighting for each key.
• Mechanical Switches ("Choc Red"): Kailh Choc Red switches are used for the keys.
• Rotary Encoders: Facilitate additional input through rotation and pressing.
• Power Management: Uses a Type-C connector $\text{[TYPE-C-31-M-12]}$ for power delivery and a power management IC $\text{[RT6150B-33GQW]}$ for regulation to 3.3V.
• Various Capacitors/Resistors: To stabilize power and manage signal characteristics.

• USB Interface: Provides connectivity for control and power using a USB Type-C interface.
• GPIO Usage: Utilizes several GPIO pins from the Raspberry Pi Pico for interfacing with switches, encoders, LEDs, and other components.

• Design: Customizable shortcuts in design software.
• Gaming: Quick access to macros and controls in games.
• Productivity: Simplified input for repetitive tasks or functions in various software environments.

graph TD;

    A[Raspberry Pi Pico 2]
    B[Raspberry Pi RP2350A]
    C[Mechanical Switches]
    C1[Choc Red]
    D[Per-key RGB LEDs]
    D1[WS2812-2020]
    E[Rotary Encoders]
    E1[PEC12R-2220F-S0024]
    F[USB Type-C Connector]
    F1[TYPE-C-31-M-12]
    G[Voltage Regulator]
    G1[RT6150B-33GQW]
    H[Crystals]
    H1[ABM8-272-T3]
    I[Diodes]
    I1[1N4007W]

    A --> |Microcontroller| B
    B --> |Control| C
    B --> |Data| D
    B --> |Interface| E
    E --> E1
    F --> F1
    G --> G1
    H --> H1
    I --> I1
    B --> |Power| G
    B --> |Clock| H
    C --> C1
    D --> D1

graph TD;

    A[Raspberry Pi Pico 2]
    B1[Raspberry Pi RP2350A]
    B2[N76E003]
    C[Mechanical Switches]
    C1[Choc Red]
    D[Per-key RGB LEDs]
    D1[WS2812-2020]
    E[Rotary Encoders]
    E1[PEC12R-2220F-S0024]
    F[USB Type-C Connector]
    F1[TYPE-C-31-M-12]
    G[Voltage Regulator]
    G1[RT6150B-33GQW]
    H[Crystals]
    H1[ABM8-272-T3]
    I[Diodes]
    I1[1N4007W]

    A --> |Main Control| B1
    B1 --> |Interface| C
    B1 --> |Control Signals| D
    B1 --> |Rotary Encoder Interface| E
    E --> E1
    F --> F1
    G --> G1
    H --> H1
    I --> I1

    A --> |Secondary Controller| B2
    B2 --> |Dedicated LED Control| D
    C --> C1
    D --> D1

1. Add the Component: First, ensure that the N76E003 is added to your schematic as a recognizable component. You may need to search for it in the Flux component database or create a custom component if it's not readily available.
2. Assign a Designator: Make sure the N76E003 has a unique designator that distinguishes it in your schematic (e.g., U_MICRO).
3. Highlight with Notes or Color:
   • Notes: You can add a note or comment next to the component in the schematic to indicate its purpose or highlight its importance.
   • Color: If the tool allows, you can change the color or outline of the component to make it stand out visually.
4. Connect to Relevant Nets: Ensure that the N76E003 is connected to the relevant parts of your schematic. For example, if it's controlling RGB LEDs, it should be connected to the necessary data lines.
5. Annotations: Use annotations to indicate the functions and connections that the N76E003 manages.