PyMagic 快速参考¶

常用控制¶

import pyb

pyb.delay(50) # 等待50ms
pyb.millis() # 从bootup到当前的ms数
pyb.repl_uart(pyb.UART(1, 9600)) # duplicate REPL on UART(1)
pyb.wfi() # 暂停CPU,等待中断
pyb.freq() # 获取CPU 和 bus 频率
pyb.freq(60000000) # 设置 CPU 频率到 60MHz
pyb.stop() # 停止 CPU, 等待外部中断

LEDs¶

from pyb import LED

led = LED(1) # 红色led
led.toggle()
led.on()
led.off()

Pins and GPIO¶

from pyb import Pin

p_out = Pin('X1', Pin.OUT_PP)
p_out.high()
p_out.low()

p_in = Pin('X2', Pin.IN, Pin.PULL_UP)
p_in.value() # 获得引脚电平值, 0 or 1

舵机控制 (Servo control)¶

from pyb import Servo

s1 = Servo(1) # 舵机在位置 1 (X1, VIN, GND)
s1.angle(45) # 移动到 45 度
s1.angle(-60, 1500) # 在1500ms内移动到 -60 度
s1.speed(50) # 连续旋转舵机

外部中断 (External interrupts)¶

from pyb import Pin, ExtInt

callback = lambda e: print("intr")
ext = ExtInt(Pin('Y1'), ExtInt.IRQ_RISING, Pin.PULL_NONE, callback)

定时器(Timers)¶

from pyb import Timer

tim = Timer(1, freq=1000)
tim.counter() # 获得计数值
tim.freq(0.5) # 0.5 Hz
tim.callback(lambda t: pyb.LED(1).toggle())

PWM (脉冲宽度调制)¶

from pyb import Pin, Timer

p = Pin('X1') # X1引脚具有 TIM2, CH1功能
tim = Timer(2, freq=1000)
ch = tim.channel(1, Timer.PWM, pin=p)
ch.pulse_width_percent(50)

ADC (模拟转数字)¶

from pyb import Pin, ADC

adc = ADC(Pin('X19'))
adc.read() # 读数, 0-4095

DAC (数字转模拟)¶

from pyb import Pin, DAC

dac = DAC(Pin('X5'))
dac.write(120) # 输出0 到 255

UART (串行总线)¶

from pyb import UART

uart = UART(1, 9600)
uart.write('hello')
uart.read(5) # 最多读取5个字节

SPI总线 (SPI bus)¶

from pyb import SPI

spi = SPI(1, SPI.MASTER, baudrate=200000, polarity=1, phase=0)
spi.send('hello')
spi.recv(5) # 在该总线上接收5个字节
spi.send_recv('hello') # 发送并接收5个字节

I2C总线 (I2C bus)¶

from pyb import I2C

i2c = I2C(1, I2C.MASTER, baudrate=100000)
i2c.scan() # 返回从机地址列表
i2c.send('hello', 0x42) # 发送5个字节到地址为0x42的从机
i2c.recv(5, 0x42) # 从从机接收5个字节
i2c.mem_read(2, 0x42, 0x10) # 从地址为0x42的从机 去读内存地址0x10的两个字节
i2c.mem_write('xy', 0x42, 0x10) # 写两个字节到地址为0x42的从机的0x10内存位置