【新手基础教程】片上外设之 I2C 的使用

I2C 的使用

关于 I2C 详细介绍请参考I2C-API 文档.

1. 使用方法

1.1. 主机模式

• 创建 I2C(软件模拟或硬件) 对象

from machine import I2C
from fpioa_manager import fm
# i2c = I2C(I2C.I2C0, freq=100000, scl=28, sda=29) # hardware i2c
i2c = I2C(I2C.I2C4, freq=100000, scl=28, sda=29,gscl=fm.fpioa.GPIOHS3,gsda=fm.fpioa.GPIOHS2) # software i2c

• 扫描从机, 返回所有从机地址

devices = i2c.scan()

• 对从机读写数据

for device in devices:
    i2c.writeto(device, b'123')
    i2c.readfrom(device, 3)

1.2. 从机模式

• 创建从机回调函数

count = 0
def on_receive(data):
    print("on_receive:",data)

def on_transmit():
    count = count+1
    print("on_transmit, send:",count)
    return count

def on_event(event):
    print("on_event:",event)

• 创建 I2C 对象

from machine import I2C
i2c = I2C(I2C.I2C0, mode=I2C.MODE_SLAVE, scl=28, sda=29, addr=0x24, addr_size=7, on_receive=on_receive, on_transmit=on_transmit, on_event=on_event)

2. 示例

• 读取所有从机地址并分别收发数据

from machine import I2C

i2c = I2C(I2C.I2C0, freq=100000, scl=28, sda=29) # software i2c

devices = i2c.scan()
print(devices)

for device in devices:
    i2c.writeto(device, b'123')
    i2c.readfrom(device, 3)

• 从机模式示例

from machine import I2C

count = 0

def on_receive(data):
    print("on_receive:",data)

def on_transmit():
    count = count+1
    print("on_transmit, send:",count)
    return count

def on_event(event):
    print("on_event:",event)

i2c = I2C(I2C.I2C0, mode=I2C.MODE_SLAVE, scl=28, sda=29, addr=0x24, addr_size=7, on_receive=on_receive, on_transmit=on_transmit, on_event=on_event)