40 Pin GPIO 接口

瑞莎 Cubie A7A 板载 40-Pin GPIO（通用输入输出）接口，为硬件扩展提供了高度灵活的接口支持。

用户可以通过 40-Pin GPIO 接口连接各类传感器、执行器、通信模块、显示屏以及其他嵌入式外设，从而快速实现物联网（IoT）、机器人控制、工业自动化等领域的原型开发与功能验证。

危险

使用 40-Pin GPIO 接口时，请注意引脚和外设的接线，请确保引脚连接正确，不当操作可能导致设备硬件损坏。

GPIO 功能

Cubie A7A 支持给板载的 GPIO 引脚外接外部设备，支持 UART、SPI、I2C、ADC 等。

FUNC9	FUNC8	FUNC7	FUNC6	FUNC5	FUNC4	FUNC3	FUNC2	FUNC1	Pin#	Pin#	FUNC1	FUNC2	FUNC3	FUNC4	FUNC5	FUNC6	FUNC7	FUNC8	FUNC9
								+3.3V	1	2	+5.0V
	PJ-EINT23	TWI11-SDA	TWI3-SDA	TWI7-SDA	UART2-CTS	UART3-RX	PWM1-5	PJ23	3	4	+5.0V
	PJ-EINT22	TWI11-SCK	TWI3-SCK	TWI7-SCK	UART2-RTS	UART3-TX	PWM1-4	PJ22	5	6	GND
	PB-EINT0	JTAG-MS			SPI2-CS0	UART0-TX	UART2-TX	PB0	7	8	PB9	UART0-TX	I2S0-DIN2	I2S0-DOUBT2	PWM1-1	WATCHDOG-SIG	TWI8-SCK	TWI0-SCK	PB-EINT9
								GND	9	10	PB10	UART0-RX	I2S0-DIN3	I2S0-DOUBT3	PWM1-2	PLL-LOCK-DBG	TWI8-SDA	TWI0-SDA	PB-EINT10
			PB-EINT1	JTAG-CK	SPI2-CLK	UART0-RX	UART2-RX	PB1	11	12	PK0	MCSIA-D0N	UART6-DCD	I2S4-BCLK	HDMI-CEC	TWI1-SDA	NCSI1-HSYNC	SGPIO-SLOAD	PK-EINT0
		PL-EINT6	S-PWM0-4	S-IR-RX	S-SPI0-MOSI	S-UART0-TX	S-JTAG-DO	PL6	13	14	GND
			PL-EINT7	S-PWM0-5	S-SPI0-MISO	S-UART0-RX	S-JTAG-DI	PL7	15	16	PJ24	PWM1-6	UART4-TX	TWI4-SCK	SPI3-CLK	PJ-EINT24
								+3.3V	17	18	PJ25	PWM1-7	UART4-RX	TWI4-SDA	SPI3-MOSI	PJ-EINT25
		PD-EINT12	PWM1-2	SPI1-MOSI	EINK-D12	DSI1-D1P	LVDS1-D1P	PD12	19	20	GND
		PD-EINT13	PWM1-3	SPI1-MISO	EINK-D13	DSI1-D1N	LVDS1-D1N	PD13	21	22	PL10	S-UART0-TX	S-TWI2-SCK	S-UART1-TX	S-PWM0-8	PL-EINT10
		PD-EINT11	PWM1-1	SPI1-CLK	EINK-D11	DSI1-D0N	LVDS1-D0N	PD11	23	24	PD10	LVDS1-D0P	DSI1-D0P	EINK-D10	SPI1-CS0	PWM1-0	PD-EINT10
								GND	25	26	PD14	LVDS1-D2P	DSI1-CKP	EINK-D14	SPI1-HOLD	UART3-RTS	PD-EINT14
		PD-EINT1	UART3-RX	TWI2-SDA	EINK-LEH	DSI1-D2N	LVDS1-CKN	PD17	27	28	PD16	LVDS1-CKP	DSI1-D2P	EINK-OEH	TWI2-SCK	UART3-TX	PD-EINT16
PK-EINT5	JTAG-MAS-CK	NCSI1-D14	SPI3-CLK	PWM1-9	PWM1-8	PCIE-CLKREQN	MCSIA-CKP	PK5	29	30	GND
PK-EINT6	JTAG-MAS-DO	NCSI1-D13	SPI3-MOSI	UART2-RTS	UART4-TX	TWI2-SCK	MCSIA-D2N	PK6	31	32	PD20	TWI0-SCK	EINK-CKV	PCIE-CLKREQN	UART4-TX	TWI3-SCK	PWM0-2
PK-EINT7	JTAG-MAS-DI	NCSI1-D12	SPI3-MISO	UART2-CTS	UART4-RX	TWI2-SDA	MCSIA-D2P	PK7	33	34	GND
PK-EINT2	SGPIO-SDATAIN	NCSI1-PCLK	TWI5-SDA	HDMI-SDA	I2S4-LRCK	UART6-DTR	MCSIA-D1N	PK2	35	36	PK1	MCSIA-D0P	UART6-DSR	I2S4-MCLK	HDMI-SCL	TWI1-SCK	NCSI1-VSYNC	SGPIO-SCLK	PK-EINT1
PK-EINT8	JTAG-MAS-NTRST	NCSI1-D11	SPI3-CS1	UART2-TX	UART4-RTS	MCSI0-MCLK	MCSIA-D3N	PK8	37	38	PK3	MCSIA-D1P	UART6-RI	I2S4-DIN0	I2S4-DOUBT1	TWI5-SCK	NCSI1-MCLK	SGPIO-SDATAOUT	PK-EINT3
								GND	39	40	PK4	MCSIA-CKN	PCIE-WAKEN	I2S4-DOUBT0	I2S4-DIN1	SPI3-CS0	NCSI1-D15	JTAG-MAS-MS	PK-EINT4

GPIO 引脚号

控制指定引脚，你想需要根据以下公式来计算引脚号：

GPIO 芯片	引脚号	计算公式
GPIOCHIP0	A ~ K	NUM + 32 * (A ~ K)
GPIOCHIP1	L ~	NUM + 32 * (L ~ )

计算示例：

PB10

GPIOCHIP0 -> 10 + 32 * (A ~ K) -> 10 + 32 * 1 -> 42

GPIOCHIP1 -> 4 + 32 * (A ~ K) -> 4 + 32 * 10 -> 324

GPIO 使用

通过板载的 40-Pin GPIO 接口，演示常见的 GPIO 使用方法。

安装 python-periphery

使用 python-periphery 库来控制 GPIO 引脚。

radxa@cubie-a7a$

sudo pip3 install python-periphery

GPIO 读取

硬件准备

主板
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来读取 PK4 引脚的高低电平。

gpio_input.py

from periphery import GPIO
import time

def read_gpio_input():
    # Configure GPIO input (modify pin number according to actual hardware)
    # Using pin 324 of /dev/gpiochip0 here (corresponds to PK4)
    try:
        # Initialize GPIO in input mode
        gpio_in = GPIO("/dev/gpiochip0", 324, "in")

        print("Starting GPIO input reading (press Ctrl+C to exit)")
        while True:
            # Read pin value
            value = gpio_in.read()
            print(f"GPIO input value: {value} (True=High, False=Low)")
            time.sleep(1)  # Read once per second

    except KeyboardInterrupt:
        print("\nProgram exited")
    except Exception as e:
        print(f"Error occurred: {e}")
    finally:
        # Ensure resources are released
        try:
            gpio_in.close()
        except:
            pass

if __name__ == "__main__":
    read_gpio_input()

测试步骤

将 PK4 引脚接 GND 或 3.3V 引脚
将代码保存为 gpio_input.py
使用 python3 gpio_input.py 命令运行测试代码

实验现象

终端会输出 False 或 True 信息。

False 代表低电平，True 代表高电平。

GPIO 输出

硬件准备

主板
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来控制 PK3 引脚输出高低电平，然后通过 PK4 引脚读取 PK3 引脚的高低电平。

gpio_output.py

from periphery import GPIO
import time

def gpio_output_with_feedback():
    # GPIO Configuration (modify pin numbers based on your hardware)
    # PK3 (output) → maps to pin 323 of /dev/gpiochip0
    # PK4 (input)  → maps to pin 324 of /dev/gpiochip0
    OUTPUT_PIN_CHIP = "/dev/gpiochip0"
    OUTPUT_PIN_NUMBER = 323  # PK3 (output pin, controlled by the script)
    INPUT_PIN_NUMBER = 324   # PK4 (input pin, reads PK3's output state)

    # Initialize GPIO objects as None first (for safe release later)
    gpio_out = None
    gpio_in = None

    try:
        # Initialize PK3 as OUTPUT mode
        gpio_out = GPIO(OUTPUT_PIN_CHIP, OUTPUT_PIN_NUMBER, "out")
        # Initialize PK4 as INPUT mode
        gpio_in = GPIO(OUTPUT_PIN_CHIP, INPUT_PIN_NUMBER, "in")

        # Print test initialization info
        print("=== GPIO Output-Input Feedback Test Started ===")
        print(f"Controlled Pin (PK3): {OUTPUT_PIN_CHIP} - Pin {OUTPUT_PIN_NUMBER} (OUTPUT)")
        print(f"Monitoring Pin (PK4): {OUTPUT_PIN_CHIP} - Pin {INPUT_PIN_NUMBER} (INPUT)")
        print("Test Behavior: PK3 toggles HIGH/LOW every 1s; PK4 verifies PK3's state")
        print("Press Ctrl+C to stop the test\n")

        # Main loop: Toggle PK3 and read PK4 feedback
        while True:
            # 1. Set PK3 to HIGH level
            gpio_out.write(True)
            time.sleep(0.1)  # Short delay for signal stabilization (avoid read lag)
            pk4_reading = gpio_in.read()
            print(f"PK3 Output: HIGH (True) | PK4 Reading: {pk4_reading}")

            # Keep PK3 HIGH for 1 second
            time.sleep(1)

            # 2. Set PK3 to LOW level
            gpio_out.write(False)
            time.sleep(0.1)  # Short delay for signal stabilization
            pk4_reading = gpio_in.read()
            print(f"PK3 Output: LOW (False) | PK4 Reading: {pk4_reading}")

            # Keep PK3 LOW for 1 second
            time.sleep(1)

    # Handle user-initiated exit (Ctrl+C)
    except KeyboardInterrupt:
        print("\n\nTest stopped by user (Ctrl+C)")
    # Handle other unexpected errors (e.g., GPIO access failure)
    except Exception as e:
        print(f"\nError during test: {str(e)}")
    # Ensure GPIO resources are released even if an error occurs
    finally:
        print("\nReleasing GPIO resources...")
        # Safely close PK3 (set to LOW first to avoid residual high level)
        if gpio_out:
            try:
                gpio_out.write(False)
                gpio_out.close()
                print(f"Successfully closed PK3 (Pin {OUTPUT_PIN_NUMBER})")
            except Exception as close_err:
                print(f"Failed to close PK3 (Pin {OUTPUT_PIN_NUMBER}): {str(close_err)}")
        # Safely close PK4
        if gpio_in:
            try:
                gpio_in.close()
                print(f"Successfully closed PK4 (Pin {INPUT_PIN_NUMBER})")
            except Exception as close_err:
                print(f"Failed to close PK4 (Pin {INPUT_PIN_NUMBER}): {str(close_err)}")
        print("Resource release complete.")

# Run the test when the script is executed directly
if __name__ == "__main__":
    gpio_output_with_feedback()

测试步骤

将 PK3 引脚和 PK4 引脚进行短接
将代码保存为 gpio_output.py
使用 sudo python3 gpio_output.py 命令运行测试代码

实验现象

终端会输出 False 或 True 信息。

False 代表低电平，True 代表高电平。

PWM 输出

硬件准备

主板
LED
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来测试 PWM 输出。

pwm_output.py

from periphery import PWM
import time

def pwm_test():
    try:
        # Configure PWM parameters - modify according to your hardware
        # Common PWM paths: /sys/class/pwm/pwmchip0/pwm0, etc.
        PWM_CHIP = 10       # PWM chip number
        PWM_CHANNEL = 2     # PWM channel number

        # Initialize PWM
        pwm = PWM(PWM_CHIP, PWM_CHANNEL)

        print(f"PWM Test: Using PWM{PWM_CHIP}.{PWM_CHANNEL} (Pin: PD12)")

        # Set PWM frequency to 1kHz
        frequency = 1000  # 1000 Hz
        pwm.frequency = frequency
        print(f"  Set frequency: {frequency} Hz")

        # Enable PWM output
        pwm.enable()
        print("  PWM enabled")

        # Test different duty cycles (0% to 100%)
        duty_cycles = [0.0, 0.25, 0.5, 0.75, 1.0]

        for duty in duty_cycles:
            pwm.duty_cycle = duty
            print(f"  Set duty cycle: {duty*100:.1f}%")
            time.sleep(1)  # Maintain current duty cycle for 1 second

        # Cleanup
        pwm.disable()
        pwm.close()
        print("  PWM disabled and closed")
        print("PWM Test completed successfully")

    except Exception as e:
        print(f"PWM Test failed: {e}")

if __name__ == "__main__":
    print("Starting PWM Signal Test...\n")
    pwm_test()

测试步骤

进入 rsetup 的 Overlay -> Manage overlays 勾选 Enable PWM1-2 选项，勾选后重启系统
将 LED 的正极连接到 PD12 引脚
将 LED 的负极连接到 GND 引脚
将代码保存为 pwm_output.py
使用 sudo python3 pwm_output.py 命令运行测试代码

实验现象

外接的 LED 会以不同的亮度闪烁，从亮到暗变化。

UART 使用

UART（通用异步收发传输器）是一种广泛使用的串行通信协议，用于在嵌入式系统、计算机和外设之间进行异步串行数据传输。

硬件准备

主板
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来测试 UART4 回环通信。

uart_example.py

from periphery import Serial
import time

def uart_test():
    try:
        # Modify the serial device path according to your hardware, common paths include /dev/ttyS0, /dev/ttyS1, /dev/ttyUSB0, etc.
        # PJ24(TX)  PJ25(RX)
        UART_DEVICE = "/dev/ttyAS4"
        BAUDRATE = 115200

        # Initialize serial port
        serial = Serial(UART_DEVICE, BAUDRATE)

        print(f"UART Test: Opening serial port {UART_DEVICE}, baud rate {BAUDRATE}")

        # Send test data
        test_message = "Hello, UART Test!\n"
        serial.write(test_message.encode())
        print(f"  Sent data: {test_message.strip()}")

        # Wait for data transmission
        time.sleep(0.1)

        # Try to read data (if loopback or other device responds)
        if serial.input_waiting() > 0:
            received_data = serial.read(serial.input_waiting())
            print(f"  Received data: {received_data.decode().strip()}")
        else:
            print("  No data received (normal unless loopback is connected)")

        serial.close()
        print("UART test completed")

    except Exception as e:
        print(f"UART test failed: {e}")

if __name__ == "__main__":
    uart_test()

测试步骤

进入 rsetup 的 Overlay -> Manage overlays 勾选 Enable UART4 选项，勾选后重启系统
将 PJ24 引脚和 PJ25 引脚短接
将代码保存为 uart_example.py
使用 sudo python3 uart_example.py 命令运行测试代码

实验现象

终端会输出发送和接收的信息，可以根据终端输出的信息判断 UART 回环测试是否成功。

I2C 使用

I2C 是一种广泛使用的同步串行通信协议，由飞利浦（现恩智浦）开发，主要用于短距离芯片间通信。

硬件准备

主板
I2C 设备（如 OLED 显示屏，其对应的 I2C 地址为 0x3C）
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来测试 I2C 通信。

i2c_example.py

from periphery import I2C

def i2c_device_detection():
    """I2C Test - Check if device exists
    Pin reference: PJ23 (SDA), PJ22 (SCL)
    """
    # Modify according to your hardware connection
    # Common I2C bus devices: /dev/i2c-0, etc.
    I2C_BUS = "/dev/i2c-7"
    TARGET_ADDR = 0x3C  # Target address to check

    i2c = None  # Initialize I2C object reference
    try:
        # Initialize I2C object
        i2c = I2C(I2C_BUS)

        # Attempt a simple read/write operation to detect device
        # Sending a single 0x00 byte as test communication
        msgs = [I2C.Message([0x00])]
        i2c.transfer(TARGET_ADDR, msgs)

        print(f"I2C Test: Device found at address 0x{TARGET_ADDR:02X}")
        return True

    except Exception as e:
        # Exception (e.g., IOError) usually indicates no device or no response
        print(f"I2C Test: No device or no response at address 0x{TARGET_ADDR:02X}: {e}")
        return False
    finally:
        # Ensure I2C resources are released
        if i2c is not None:
            try:
                i2c.close()
            except:
                pass

if __name__ == "__main__":
    print("Starting I2C Device Detection...")
    i2c_device_detection()
    print("I2C Test completed")

测试步骤

进入 rsetup 的 Overlay -> Manage overlays 勾选 Enable TWI7 选项，勾选后重启系统
将 OLED 显示屏的 SCL 引脚连接到 PJ22 引脚，SDA 引脚连接到 PJ23 引脚，VCC 连接到 5V，GND 连接到 GND
将代码保存为 i2c_example.py
使用 sudo python3 i2c_example.py 命令运行测试代码

实验现象

脚本功能是检查指定 I2C 总线上的特定地址是否存在可响应的 I2C 设备，可以判断 I2C 设备是否正常工作。

SPI 使用

SPI（串行外设接口）是一种高速、全双工、同步串行通信协议，由 Motorola（现为 NXP ）开发，主要用于短距离芯片间通信，常见于传感器、存储器（如 Flash ）、显示屏等设备与微控制器之间的数据传输。

硬件准备

主板
杜邦线

软件准备

测试代码

以下代码是使用 python-periphery 库来测试 SPI 回环通信。

spi_example.py

from periphery import SPI

def spi_communication_test():
    # Data to be transmitted (4 bytes)
    transmit_data = [0xAA, 0xBB, 0xCC, 0xDD]

    try:
        # Initialize SPI resource
        # Parameters: SPI device path, mode 0, 1MHz clock frequency
        spi = SPI("/dev/spidev3.0", 0, 1000000)

        # Transmit data and receive response simultaneously
        # SPI is full-duplex, so data is sent and received at the same time
        received_data = spi.transfer(transmit_data)

        # Print test results
        print("SPI Test:")
        print("  Transmitted data: [0x{:02x}, 0x{:02x}, 0x{:02x}, 0x{:02x}]".format(*transmit_data))
        print("  Received data:    [0x{:02x}, 0x{:02x}, 0x{:02x}, 0x{:02x}]".format(*received_data))

    except Exception as e:
        print(f"SPI Test failed: {e}")
    finally:
        # Ensure SPI resource is released
        try:
            spi.close()
        except:
            pass

if __name__ == "__main__":
    print("Starting SPI Communication Test...\n")
    spi_communication_test()
    print("\nSPI Test completed")

测试步骤

进入 rsetup 的 Overlay -> Manage overlays 勾选 Enable spidev on SPI3 选项，勾选后重启系统
将 PK6 引脚和 PK7 引脚连接
将代码保存为 spi_example.py
使用 sudo python3 spi_example.py 命令运行测试代码

实验现象

终端会输出发送和接收的信息，可以根据发送和接收的数据是否一致判断 SPI 回环测试是否成功。

GPIO 功能​

GPIO 引脚号​

GPIO 使用​

安装 python-periphery​

GPIO 读取​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

GPIO 输出​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

PWM 输出​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

UART 使用​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

I2C 使用​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

SPI 使用​

硬件准备​

软件准备​

测试代码​

测试步骤​

实验现象​

GPIO 功能

GPIO 引脚号

GPIO 使用

安装 python-periphery

GPIO 读取

硬件准备

软件准备

测试代码

测试步骤

实验现象

GPIO 输出

硬件准备

软件准备

测试代码

测试步骤

实验现象

PWM 输出

硬件准备

软件准备

测试代码

测试步骤

实验现象

UART 使用

硬件准备

软件准备

测试代码

测试步骤

实验现象

I2C 使用

硬件准备

软件准备

测试代码

测试步骤

实验现象

SPI 使用

硬件准备

软件准备

测试代码

测试步骤

实验现象