外设 配置 Guide

This guide provides detailed examples for configuring all peripheral types in the Nexus Embedded Platform using Kconfig.

概述

The Nexus platform supports comprehensive peripheral configuration through Kconfig. Each peripheral type has:

  • Enable/Disable Control: Top-level enable for the peripheral type

  • Instance Configuration: Individual configuration for each peripheral instance

  • Parameter Settings: Detailed parameters for each instance (baud rate, mode, buffers, etc.)

  • Platform-Specific Options: Options that vary by platform

外设 Types

The following peripheral types are supported:

  • UART: Universal Asynchronous Receiver/Transmitter

  • GPIO: General Purpose Input/Output

  • SPI: Serial Peripheral Interface

  • I2C: Inter-Integrated Circuit

  • Timer: Hardware timers with PWM support

  • ADC: Analog-to-Digital Converter

  • CAN: Controller Area Network (platform-dependent)

配置 Pattern

All peripherals follow a consistent configuration pattern:

# 1. Enable peripheral type
config <PLATFORM>_<PERIPHERAL>_ENABLE
    bool "Enable <PERIPHERAL> support"
    default y

# 2. Enable specific instance
menuconfig INSTANCE_<PLATFORM>_<PERIPHERAL>_<N>
    bool "Enable <PERIPHERAL><N>"
    default y
    depends on <PLATFORM>_<PERIPHERAL>_ENABLE

# 3. Configure instance parameters
if INSTANCE_<PLATFORM>_<PERIPHERAL>_<N>

config <PERIPHERAL><N>_<PARAMETER>
    <type> "<Parameter description>"
    default <value>

endif

UART 配置

概述

UART (Universal Asynchronous Receiver/Transmitter) provides serial communication. Configuration includes:

  • Baud rate

  • Data bits (5-9)

  • Stop bits (1-2)

  • Parity (None, Odd, Even)

  • Transfer mode (Polling, Interrupt, DMA)

  • Buffer sizes

必需 参数

All UART instances require:

  • UART<N>_BAUDRATE: Communication speed in bits per second

  • UART<N>_DATA_BITS: Number of data bits per frame

  • UART<N>_STOP_BITS: Number of stop bits

  • UART<N>_PARITY: Parity checking mode

  • UART<N>_MODE: Transfer mode (Polling/Interrupt/DMA)

  • UART<N>_TX_BUFFER_SIZE: Transmit buffer size in bytes

  • UART<N>_RX_BUFFER_SIZE: Receive buffer size in bytes

Basic UART 配置

Enable UART and configure UART0:

# Enable UART peripheral
CONFIG_NATIVE_UART_ENABLE=y

# Enable UART0 instance
CONFIG_INSTANCE_NX_UART_0=y

# Configure UART0 parameters
CONFIG_UART0_BAUDRATE=115200
CONFIG_UART0_DATA_BITS=8
CONFIG_UART0_STOP_BITS=1
CONFIG_NX_UART0_PARITY_NONE=y
CONFIG_NX_UART0_MODE_INTERRUPT=y
CONFIG_UART0_TX_BUFFER_SIZE=256
CONFIG_UART0_RX_BUFFER_SIZE=256

Generated Configuration:

#define NX_CONFIG_NATIVE_UART_ENABLE 1
#define NX_CONFIG_INSTANCE_NX_UART_0 1
#define NX_CONFIG_UART0_BAUDRATE 115200
#define NX_CONFIG_UART0_DATA_BITS 8
#define NX_CONFIG_UART0_STOP_BITS 1
#define NX_CONFIG_UART0_PARITY_VALUE 0
#define NX_CONFIG_UART0_MODE_VALUE 1
#define NX_CONFIG_UART0_TX_BUFFER_SIZE 256
#define NX_CONFIG_UART0_RX_BUFFER_SIZE 256

UART Transfer Modes

Polling Mode:

CONFIG_NX_UART0_MODE_POLLING=y

  • Simplest implementation

  • Blocks CPU during transfers

  • No interrupt overhead

  • Best for: Simple applications, debugging

Interrupt Mode:

CONFIG_NX_UART0_MODE_INTERRUPT=y

  • Non-blocking transfers

  • Uses interrupts for TX/RX

  • Moderate CPU overhead

  • Best for: General-purpose applications

DMA Mode:

CONFIG_NX_UART0_MODE_DMA=y

  • Most efficient for large transfers

  • Minimal CPU involvement

  • Requires DMA controller

  • Best for: High-throughput applications

UART Parity 配置

No Parity:

CONFIG_NX_UART0_PARITY_NONE=y

Odd Parity:

CONFIG_NX_UART0_PARITY_ODD=y

Even Parity:

CONFIG_NX_UART0_PARITY_EVEN=y

Common UART Configurations

Debug Console (115200 8N1):

CONFIG_NATIVE_UART_ENABLE=y
CONFIG_INSTANCE_NX_UART_0=y
CONFIG_UART0_BAUDRATE=115200
CONFIG_UART0_DATA_BITS=8
CONFIG_UART0_STOP_BITS=1
CONFIG_NX_UART0_PARITY_NONE=y
CONFIG_NX_UART0_MODE_INTERRUPT=y
CONFIG_UART0_TX_BUFFER_SIZE=512
CONFIG_UART0_RX_BUFFER_SIZE=512

Low-Speed Sensor (9600 8N1):

CONFIG_INSTANCE_NX_UART_1=y
CONFIG_UART1_BAUDRATE=9600
CONFIG_UART1_DATA_BITS=8
CONFIG_UART1_STOP_BITS=1
CONFIG_NX_UART1_PARITY_NONE=y
CONFIG_NX_UART1_MODE_POLLING=y
CONFIG_UART1_TX_BUFFER_SIZE=64
CONFIG_UART1_RX_BUFFER_SIZE=64

High-Speed Data (921600 8N1 DMA):

CONFIG_INSTANCE_NX_UART_2=y
CONFIG_UART2_BAUDRATE=921600
CONFIG_UART2_DATA_BITS=8
CONFIG_UART2_STOP_BITS=1
CONFIG_NX_UART2_PARITY_NONE=y
CONFIG_NX_UART2_MODE_DMA=y
CONFIG_UART2_TX_BUFFER_SIZE=2048
CONFIG_UART2_RX_BUFFER_SIZE=2048

Industrial Protocol (19200 7E1):

CONFIG_INSTANCE_NX_UART_3=y
CONFIG_UART3_BAUDRATE=19200
CONFIG_UART3_DATA_BITS=7
CONFIG_UART3_STOP_BITS=1
CONFIG_NX_UART3_PARITY_EVEN=y
CONFIG_NX_UART3_MODE_INTERRUPT=y
CONFIG_UART3_TX_BUFFER_SIZE=256
CONFIG_UART3_RX_BUFFER_SIZE=256

Multiple UART Instances

Configure multiple UARTs:

# Enable UART peripheral
CONFIG_NATIVE_UART_ENABLE=y
CONFIG_NATIVE_UART_MAX_INSTANCES=4

# UART0: Debug console
CONFIG_INSTANCE_NX_UART_0=y
CONFIG_UART0_BAUDRATE=115200
CONFIG_NX_UART0_MODE_INTERRUPT=y

# UART1: GPS module
CONFIG_INSTANCE_NX_UART_1=y
CONFIG_UART1_BAUDRATE=9600
CONFIG_NX_UART1_MODE_INTERRUPT=y

# UART2: Bluetooth module
CONFIG_INSTANCE_NX_UART_2=y
CONFIG_UART2_BAUDRATE=115200
CONFIG_NX_UART2_MODE_DMA=y

# UART3: RS485 interface
CONFIG_INSTANCE_NX_UART_3=y
CONFIG_UART3_BAUDRATE=38400
CONFIG_NX_UART3_MODE_INTERRUPT=y

GPIO 配置

概述

GPIO (General Purpose Input/Output) provides digital I/O pin control. Configuration includes:

  • Pin mode (Input, Output Push-Pull, Output Open-Drain, Alternate Function, Analog)

  • Pull configuration (None, Pull-up, Pull-down)

  • Speed (Low, Medium, High, Very High)

  • Initial output value

必需 参数

All GPIO pins require:

  • GPIO<PORT>_PIN<N>_MODE: Pin operating mode

  • GPIO<PORT>_PIN<N>_PULL: Pull-up/pull-down configuration

  • GPIO<PORT>_PIN<N>_SPEED: Pin speed/slew rate

  • GPIO<PORT>_PIN<N>_OUTPUT_VALUE: Initial output value (for output modes)

Basic GPIO 配置

Enable GPIO and configure GPIOA PIN0:

# Enable GPIO peripheral
CONFIG_NATIVE_GPIO_ENABLE=y

# Enable GPIOA port
CONFIG_INSTANCE_NX_GPIOA=y

# Enable and configure GPIOA PIN0
CONFIG_INSTANCE_NX_GPIOA_PIN0=y
CONFIG_NX_GPIOA_PIN0_MODE_OUTPUT_PP=y
CONFIG_NX_GPIOA_PIN0_PULL_NONE=y
CONFIG_NX_GPIOA_PIN0_SPEED_MEDIUM=y
CONFIG_GPIOA_PIN0_OUTPUT_VALUE=0

Generated Configuration:

#define NX_CONFIG_NATIVE_GPIO_ENABLE 1
#define NX_CONFIG_INSTANCE_NX_GPIOA 1
#define NX_CONFIG_INSTANCE_NX_GPIOA_PIN0 1
#define NX_CONFIG_GPIOA_PIN0_MODE 1
#define NX_CONFIG_GPIOA_PIN0_PULL_VALUE 0
#define NX_CONFIG_GPIOA_PIN0_SPEED_VALUE 1
#define NX_CONFIG_GPIOA_PIN0_OUTPUT_VALUE 0

GPIO 引脚 Modes

Input Mode:

CONFIG_NX_GPIOA_PIN0_MODE_INPUT=y
CONFIG_NX_GPIOA_PIN0_PULL_UP=y  # Optional pull-up

  • Read digital input

  • High impedance

  • Can enable pull-up/pull-down

Output Push-Pull:

CONFIG_NX_GPIOA_PIN0_MODE_OUTPUT_PP=y
CONFIG_GPIOA_PIN0_OUTPUT_VALUE=0

  • Drive high or low

  • Strong output

  • Most common output mode

Output Open-Drain:

CONFIG_NX_GPIOA_PIN0_MODE_OUTPUT_OD=y
CONFIG_NX_GPIOA_PIN0_PULL_UP=y  # External pull-up required

  • Can only pull low

  • Requires external pull-up

  • Used for I2C, 1-Wire

Alternate 函数 Push-Pull:

CONFIG_NX_GPIOA_PIN0_MODE_AF_PP=y

  • Controlled by peripheral (UART, SPI, etc.)

  • Push-pull output

Alternate 函数 Open-Drain:

CONFIG_NX_GPIOA_PIN0_MODE_AF_OD=y

  • Controlled by peripheral

  • Open-drain output

Analog Mode:

CONFIG_NX_GPIOA_PIN0_MODE_ANALOG=y

  • Used for ADC/DAC

  • Disables digital circuitry

GPIO Pull 配置

No Pull:

CONFIG_NX_GPIOA_PIN0_PULL_NONE=y

Pull-Up:

CONFIG_NX_GPIOA_PIN0_PULL_UP=y

Pull-Down:

CONFIG_NX_GPIOA_PIN0_PULL_DOWN=y

GPIO Speed 配置

Low Speed:

CONFIG_NX_GPIOA_PIN0_SPEED_LOW=y

  • Lowest EMI

  • Suitable for slow signals

Medium Speed:

CONFIG_NX_GPIOA_PIN0_SPEED_MEDIUM=y

  • Balanced performance

  • Default for most applications

High Speed:

CONFIG_NX_GPIOA_PIN0_SPEED_HIGH=y

  • Fast switching

  • Higher EMI

Very High Speed:

CONFIG_NX_GPIOA_PIN0_SPEED_VERY_HIGH=y

  • Fastest switching

  • Highest EMI

  • For high-speed protocols

Common GPIO Configurations

LED Output:

CONFIG_INSTANCE_NX_GPIOA_PIN0=y
CONFIG_NX_GPIOA_PIN0_MODE_OUTPUT_PP=y
CONFIG_NX_GPIOA_PIN0_PULL_NONE=y
CONFIG_NX_GPIOA_PIN0_SPEED_LOW=y
CONFIG_GPIOA_PIN0_OUTPUT_VALUE=0

Button Input:

CONFIG_INSTANCE_NX_GPIOA_PIN1=y
CONFIG_NX_GPIOA_PIN1_MODE_INPUT=y
CONFIG_NX_GPIOA_PIN1_PULL_UP=y
CONFIG_NX_GPIOA_PIN1_SPEED_LOW=y

I2C SCL/SDA (Open-Drain):

# SCL
CONFIG_INSTANCE_NX_GPIOA_PIN2=y
CONFIG_NX_GPIOA_PIN2_MODE_AF_OD=y
CONFIG_NX_GPIOA_PIN2_PULL_UP=y
CONFIG_NX_GPIOA_PIN2_SPEED_HIGH=y

# SDA
CONFIG_INSTANCE_NX_GPIOB_PIN0=y
CONFIG_NX_GPIOB_PIN0_MODE_AF_OD=y
CONFIG_NX_GPIOB_PIN0_PULL_UP=y
CONFIG_NX_GPIOB_PIN0_SPEED_HIGH=y

SPI Pins:

# SCK
CONFIG_INSTANCE_NX_GPIOA_PIN0=y
CONFIG_NX_GPIOA_PIN0_MODE_AF_PP=y
CONFIG_NX_GPIOA_PIN0_SPEED_VERY_HIGH=y

# MOSI
CONFIG_INSTANCE_NX_GPIOA_PIN1=y
CONFIG_NX_GPIOA_PIN1_MODE_AF_PP=y
CONFIG_NX_GPIOA_PIN1_SPEED_VERY_HIGH=y

# MISO
CONFIG_INSTANCE_NX_GPIOA_PIN2=y
CONFIG_NX_GPIOA_PIN2_MODE_INPUT=y
CONFIG_NX_GPIOA_PIN2_PULL_NONE=y
CONFIG_NX_GPIOA_PIN2_SPEED_VERY_HIGH=y

Multiple GPIO Ports

Configure multiple GPIO ports:

# Enable GPIO
CONFIG_NATIVE_GPIO_ENABLE=y

# GPIOA: LEDs and buttons
CONFIG_INSTANCE_NX_GPIOA=y
CONFIG_INSTANCE_NX_GPIOA_PIN0=y  # LED1
CONFIG_NX_GPIOA_PIN0_MODE_OUTPUT_PP=y
CONFIG_INSTANCE_NX_GPIOA_PIN1=y  # LED2
CONFIG_NX_GPIOA_PIN1_MODE_OUTPUT_PP=y
CONFIG_INSTANCE_NX_GPIOA_PIN2=y  # Button
CONFIG_NX_GPIOA_PIN2_MODE_INPUT=y
CONFIG_NX_GPIOA_PIN2_PULL_UP=y

# GPIOB: I2C interface
CONFIG_INSTANCE_NX_GPIOB=y
CONFIG_INSTANCE_NX_GPIOB_PIN0=y  # I2C SCL
CONFIG_NX_GPIOB_PIN0_MODE_AF_OD=y
CONFIG_NX_GPIOB_PIN0_PULL_UP=y

# GPIOC: Analog inputs
CONFIG_INSTANCE_NX_GPIOC=y
CONFIG_INSTANCE_NX_GPIOC_PIN0=y  # ADC input
CONFIG_NX_GPIOC_PIN0_MODE_ANALOG=y

SPI 配置

概述

SPI (Serial Peripheral Interface) provides high-speed synchronous serial communication. Configuration includes:

  • Maximum speed (Hz)

  • 时钟 polarity (CPOL)

  • 时钟 phase (CPHA)

  • Bit order (MSB/LSB first)

  • Buffer sizes

必需 参数

All SPI instances require:

  • SPI<N>_MAX_SPEED: Maximum SPI clock speed in Hz

  • SPI<N>_CPOL: Clock polarity (0 or 1)

  • SPI<N>_CPHA: Clock phase (0 or 1)

  • SPI<N>_BIT_ORDER: Bit order (MSB or LSB first)

  • SPI<N>_TX_BUFFER_SIZE: Transmit buffer size in bytes

  • SPI<N>_RX_BUFFER_SIZE: Receive buffer size in bytes

Basic SPI 配置

Enable SPI and configure SPI0:

# Enable SPI peripheral
CONFIG_NATIVE_SPI_ENABLE=y

# Enable SPI0 instance
CONFIG_INSTANCE_NX_SPI_0=y

# Configure SPI0 parameters
CONFIG_SPI0_MAX_SPEED=1000000
CONFIG_NX_SPI0_CPOL_LOW=y
CONFIG_NX_SPI0_CPHA_EDGE_1=y
CONFIG_NX_SPI0_MSB_FIRST=y
CONFIG_SPI0_TX_BUFFER_SIZE=256
CONFIG_SPI0_RX_BUFFER_SIZE=256

SPI Modes

SPI has four modes based on CPOL and CPHA:

Mode 0 (CPOL=0, CPHA=0):

CONFIG_NX_SPI0_CPOL_LOW=y
CONFIG_NX_SPI0_CPHA_EDGE_1=y

  • 时钟 idle low

  • Data sampled on first edge

  • Most common mode

Mode 1 (CPOL=0, CPHA=1):

CONFIG_NX_SPI0_CPOL_LOW=y
CONFIG_NX_SPI0_CPHA_EDGE_2=y

  • 时钟 idle low

  • Data sampled on second edge

Mode 2 (CPOL=1, CPHA=0):

CONFIG_NX_SPI0_CPOL_HIGH=y
CONFIG_NX_SPI0_CPHA_EDGE_1=y

  • 时钟 idle high

  • Data sampled on first edge

Mode 3 (CPOL=1, CPHA=1):

CONFIG_NX_SPI0_CPOL_HIGH=y
CONFIG_NX_SPI0_CPHA_EDGE_2=y

  • 时钟 idle high

  • Data sampled on second edge

Common SPI Configurations

SD Card (Mode 0, 25 MHz):

CONFIG_INSTANCE_NX_SPI_0=y
CONFIG_SPI0_MAX_SPEED=25000000
CONFIG_NX_SPI0_CPOL_LOW=y
CONFIG_NX_SPI0_CPHA_EDGE_1=y
CONFIG_NX_SPI0_MSB_FIRST=y
CONFIG_SPI0_TX_BUFFER_SIZE=512
CONFIG_SPI0_RX_BUFFER_SIZE=512

Flash Memory (Mode 0, 10 MHz):

CONFIG_INSTANCE_NX_SPI_1=y
CONFIG_SPI1_MAX_SPEED=10000000
CONFIG_NX_SPI1_CPOL_LOW=y
CONFIG_NX_SPI1_CPHA_EDGE_1=y
CONFIG_NX_SPI1_MSB_FIRST=y
CONFIG_SPI1_TX_BUFFER_SIZE=256
CONFIG_SPI1_RX_BUFFER_SIZE=256

Display (Mode 3, 20 MHz):

CONFIG_INSTANCE_NX_SPI_2=y
CONFIG_SPI2_MAX_SPEED=20000000
CONFIG_NX_SPI2_CPOL_HIGH=y
CONFIG_NX_SPI2_CPHA_EDGE_2=y
CONFIG_NX_SPI2_MSB_FIRST=y
CONFIG_SPI2_TX_BUFFER_SIZE=1024
CONFIG_SPI2_RX_BUFFER_SIZE=128

I2C 配置

概述

I2C (Inter-Integrated Circuit) provides multi-master, multi-slave serial communication. Configuration includes:

  • Speed mode (Standard 100kHz, Fast 400kHz, Fast Plus 1MHz)

  • Addressing mode (7-bit or 10-bit)

  • Buffer sizes

必需 参数

All I2C instances require:

  • I2C<N>_SPEED: I2C bus speed mode

  • I2C<N>_ADDR_MODE: Addressing mode (7-bit or 10-bit)

  • I2C<N>_TX_BUFFER_SIZE: Transmit buffer size in bytes

  • I2C<N>_RX_BUFFER_SIZE: Receive buffer size in bytes

Basic I2C 配置

Enable I2C and configure I2C0:

# Enable I2C peripheral
CONFIG_NATIVE_I2C_ENABLE=y

# Enable I2C0 instance
CONFIG_INSTANCE_NX_I2C_0=y

# Configure I2C0 parameters
CONFIG_NX_I2C0_SPEED_FAST=y
CONFIG_NX_I2C0_ADDR_BIT_7=y
CONFIG_I2C0_TX_BUFFER_SIZE=256
CONFIG_I2C0_RX_BUFFER_SIZE=256

I2C Speed Modes

Standard Mode (100 kHz):

CONFIG_NX_I2C0_SPEED_STANDARD=y

  • 100 kHz bus speed

  • Longest cable length

  • Best compatibility

Fast Mode (400 kHz):

CONFIG_NX_I2C0_SPEED_FAST=y

  • 400 kHz bus speed

  • Most common mode

  • Good balance

Fast Mode Plus (1 MHz):

CONFIG_NX_I2C0_SPEED_FAST_PLUS=y

  • 1 MHz bus speed

  • Shortest cable length

  • Requires capable devices

I2C Addressing Modes

7-bit Addressing:

CONFIG_NX_I2C0_ADDR_BIT_7=y

  • Standard addressing

  • 128 possible addresses

  • Most common

10-bit Addressing:

CONFIG_NX_I2C0_ADDR_BIT_10=y

  • Extended addressing

  • 1024 possible addresses

  • Less common

Common I2C Configurations

Sensor Bus (Fast Mode, 7-bit):

CONFIG_INSTANCE_NX_I2C_0=y
CONFIG_NX_I2C0_SPEED_FAST=y
CONFIG_NX_I2C0_ADDR_BIT_7=y
CONFIG_I2C0_TX_BUFFER_SIZE=128
CONFIG_I2C0_RX_BUFFER_SIZE=128

EEPROM (Standard Mode, 7-bit):

CONFIG_INSTANCE_NX_I2C_1=y
CONFIG_NX_I2C1_SPEED_STANDARD=y
CONFIG_NX_I2C1_ADDR_BIT_7=y
CONFIG_I2C1_TX_BUFFER_SIZE=256
CONFIG_I2C1_RX_BUFFER_SIZE=256

High-Speed Sensors (Fast Plus, 7-bit):

CONFIG_INSTANCE_NX_I2C_2=y
CONFIG_NX_I2C2_SPEED_FAST_PLUS=y
CONFIG_NX_I2C2_ADDR_BIT_7=y
CONFIG_I2C2_TX_BUFFER_SIZE=512
CONFIG_I2C2_RX_BUFFER_SIZE=512

定时器 配置

概述

Timer peripherals provide timing, counting, and PWM generation. Configuration includes:

  • 定时器 frequency (Hz)

  • Counter mode (Up, Down, Center-aligned)

  • PWM channel count

必需 参数

All Timer instances require:

  • TIMER<N>_FREQUENCY: Timer base frequency in Hz

  • TIMER<N>_MODE: Counter mode

  • TIMER<N>_CHANNEL_COUNT: Number of PWM channels

Basic 定时器 配置

Enable Timer and configure TIMER0:

# Enable Timer peripheral
CONFIG_NATIVE_TIMER_ENABLE=y

# Enable TIMER0 instance
CONFIG_INSTANCE_NX_TIMER_0=y

# Configure TIMER0 parameters
CONFIG_TIMER0_FREQUENCY=1000000
CONFIG_NX_TIMER0_MODE_UP=y
CONFIG_TIMER0_CHANNEL_COUNT=4

定时器 Counter Modes

Up Counting:

CONFIG_NX_TIMER0_MODE_UP=y

  • Counts from 0 to period

  • Most common mode

Down Counting:

CONFIG_NX_TIMER0_MODE_DOWN=y

  • Counts from period to 0

Center-Aligned:

CONFIG_NX_TIMER0_MODE_CENTER=y

  • Counts up then down

  • Used for symmetric PWM

Common 定时器 Configurations

PWM Generation (1 MHz, 4 channels):

CONFIG_INSTANCE_NX_TIMER_0=y
CONFIG_TIMER0_FREQUENCY=1000000
CONFIG_NX_TIMER0_MODE_UP=y
CONFIG_TIMER0_CHANNEL_COUNT=4

Periodic Interrupt (10 kHz):

CONFIG_INSTANCE_NX_TIMER_1=y
CONFIG_TIMER1_FREQUENCY=10000
CONFIG_NX_TIMER1_MODE_UP=y
CONFIG_TIMER1_CHANNEL_COUNT=0

Motor Control (20 kHz, Center-aligned):

CONFIG_INSTANCE_NX_TIMER_2=y
CONFIG_TIMER2_FREQUENCY=20000
CONFIG_NX_TIMER2_MODE_CENTER=y
CONFIG_TIMER2_CHANNEL_COUNT=6

ADC 配置

概述

ADC (Analog-to-Digital Converter) converts analog signals to digital values. Configuration includes:

  • Resolution (8, 10, 12, 16 bits)

  • Sampling time

  • Channel count

必需 参数

All ADC instances require:

  • ADC<N>_RESOLUTION: ADC resolution in bits

  • ADC<N>_SAMPLE_TIME: Sampling time

  • ADC<N>_CHANNEL_COUNT: Number of ADC channels

Basic ADC 配置

Enable ADC and configure ADC0:

# Enable ADC peripheral
CONFIG_NATIVE_ADC_ENABLE=y

# Enable ADC0 instance
CONFIG_INSTANCE_NX_ADC_0=y

# Configure ADC0 parameters
CONFIG_NX_ADC0_RESOLUTION_12=y
CONFIG_NX_ADC0_SAMPLE_TIME_MEDIUM=y
CONFIG_ADC0_CHANNEL_COUNT=16

ADC Resolution

8-bit Resolution:

CONFIG_NX_ADC0_RESOLUTION_8=y

  • 256 levels (0-255)

  • Fastest conversion

  • Lowest precision

10-bit Resolution:

CONFIG_NX_ADC0_RESOLUTION_10=y

  • 1024 levels (0-1023)

  • Good balance

12-bit Resolution:

CONFIG_NX_ADC0_RESOLUTION_12=y

  • 4096 levels (0-4095)

  • Most common

  • Good precision

16-bit Resolution:

CONFIG_NX_ADC0_RESOLUTION_16=y

  • 65536 levels (0-65535)

  • Highest precision

  • Slowest conversion

ADC Sampling Time

Fast Sampling:

CONFIG_NX_ADC0_SAMPLE_TIME_FAST=y

  • Shortest sampling time

  • Requires low source impedance

Medium Sampling:

CONFIG_NX_ADC0_SAMPLE_TIME_MEDIUM=y

  • Balanced sampling time

  • Most common

Slow Sampling:

CONFIG_NX_ADC0_SAMPLE_TIME_SLOW=y

  • Longest sampling time

  • Best for high impedance sources

Common ADC Configurations

General Purpose (12-bit, Medium):

CONFIG_INSTANCE_NX_ADC_0=y
CONFIG_NX_ADC0_RESOLUTION_12=y
CONFIG_NX_ADC0_SAMPLE_TIME_MEDIUM=y
CONFIG_ADC0_CHANNEL_COUNT=8

High-Speed (8-bit, Fast):

CONFIG_INSTANCE_NX_ADC_1=y
CONFIG_NX_ADC1_RESOLUTION_BIT_8=y
CONFIG_NX_ADC1_SAMPLE_TIME_FAST=y
CONFIG_ADC1_CHANNEL_COUNT=4

High-Precision (16-bit, Slow):

CONFIG_INSTANCE_NX_ADC_2=y
CONFIG_NX_ADC2_RESOLUTION_BIT_16=y
CONFIG_NX_ADC2_SAMPLE_TIME_SLOW=y
CONFIG_ADC2_CHANNEL_COUNT=4

ADC Buffer 配置

Enable ADC Buffer for multi-channel sampling:

# Enable ADC Buffer
CONFIG_NATIVE_ADC_BUFFER_ENABLE=y

# Configure ADC_BUFFER0
CONFIG_INSTANCE_NX_ADC_BUFFER_0=y
CONFIG_ADC_BUFFER0_CHANNEL_COUNT=4
CONFIG_ADC_BUFFER0_BUFFER_SIZE=256
CONFIG_NX_ADC_BUFFER0_TRIGGER_TIMER=y

另请参阅