2. [Micropython]TPYBoard v202 快速入门¶
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2.1. TPYBoard v202简介¶
TPYBoard v202是遵照MIT协议，以MicroPython为基础，研发的一款支持Python和lua语言的Wifi通信开发板，TPYBoard v202有9个通用GPIO口，1费ADC接口，1个SPI接口，1个I2C 接口，1个USART接口。
通用方法 machine类库：
import machine
machine.freq() # get the current frequency of the CPU
machine.freq(160000000) # set the CPU frequency to 160 MHz
esp类库：
import esp
esp.osdebug(None) # turn off vendor O/S debugging messages
esp.osdebug(0) # redirect vendor O/S debugging messages to UART(0)
联网 network类库：
import network
wlan = network.WLAN(network.STA_IF) # create station interface
wlan.active(True) # activate the interface
wlan.scan() # scan for access points
wlan.isconnected() # check if the station is connected to an AP
wlan.connect('essid', 'password') # connect to an AP
wlan.config('mac') # get the interface's MAC adddress
wlan.ifconfig() # get the interface's IP/netmask/gw/DNS addresses
ap = network.WLAN(network.AP_IF) # create access-point interface
ap.active(True) # activate the interface
ap.config(essid='ESP-AP') # set the ESSID of the access point
连接到本地WiFi网络：
def do_connect():
import network
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
if not wlan.isconnected():
print('connecting to network...')
wlan.connect('essid', 'password')
while not wlan.isconnected():
pass
print('network config:', wlan.ifconfig())
延迟和时间 time 类库
import time
time.sleep(1) # sleep for 1 second
time.sleep_ms(500) # sleep for 500 milliseconds
time.sleep_us(10) # sleep for 10 microseconds
start = time.ticks_ms() # get millisecond counter
delta = time.ticks_diff(time.ticks_ms(), start) # compute time difference
计时器
import time
time.sleep(1) # sleep for 1 second
time.sleep_ms(500) # sleep for 500 milliseconds
time.sleep_us(10) # sleep for 10 microseconds
start = time.ticks_ms() # get millisecond counter
delta = time.ticks_diff(time.ticks_ms(), start) # compute time difference
周期以毫秒为单位。
引脚和GPIO 使用machine.Pin类库：
from machine import Pin
p0 = Pin(0, Pin.OUT) # create output pin on GPIO0
p0.high() # set pin to high
p0.low() # set pin to low
p0.value(1) # set pin to high
p2 = Pin(2, Pin.IN) # create input pin on GPIO2
print(p2.value()) # get value, 0 or 1
p4 = Pin(4, Pin.IN, Pin.PULL_UP) # enable internal pull-up resistor
p5 = Pin(5, Pin.OUT, value=1) # set pin high on creation
可用引脚为：0,1,2,3,4,5,12,13,14,15,16，其对应于ESP8266芯片的实际GPIO引脚号。请注意，许多终端用户板使用自己的adhoc引脚编号（标记为D0，D1，...）。由于MicroPython支持不同的单板和模块，所以选择物理引脚编号作为最低的公分母。对于逻辑引脚和物理芯片引脚之间的映射，请参阅电路板文档。
注意，引脚（1）和引脚（3）分别是REPL UART TX和RX。还要注意，Pin（16）是一个特殊的引脚（用于从深睡眠模式唤醒），可能不适用于更高级别的类 Neopixel。
PWM（脉宽调制） 除引脚（16）外的所有引脚都可以使能PWM。所有通道都有一个频率，范围介于1到1000（以Hz为单位）。占空比介于0和1023之间。
使用machine.PWM类：
from machine import Pin, PWM
pwm0 = PWM(Pin(0)) # create PWM object from a pin
pwm0.freq() # get current frequency
pwm0.freq(1000) # set frequency
pwm0.duty() # get current duty cycle
pwm0.duty(200) # set duty cycle
pwm0.deinit() # turn off PWM on the pin
pwm2 = PWM(Pin(2), freq=500, duty=512) # create and configure in one go
ADC（模数转换） ADC在专用引脚上可用。请注意，ADC引脚上的输入电压必须在0v和1.0v之间。
使用machine.ADC类：
from machine import ADC
adc = ADC(0) # create ADC object on ADC pin
adc.read() # read value, 0-1024
SPI总线 有两个SPI驱动程序。一个在软件（bit-banging）中实现，并可在所有引脚上工作：
from machine import Pin, SPI
# construct an SPI bus on the given pins# polarity is the idle state of SCK# phase=0 means sample on the first edge of SCK, phase=1 means the second
spi = SPI(-1, baudrate=100000, polarity=1, phase=0, sck=Pin(0), mosi=Pin(2), miso=Pin(4))
spi.init(baudrate=200000) # set the baudrate
spi.read(10) # read 10 bytes on MISO
spi.read(10, 0xff) # read 10 bytes while outputing 0xff on MOSI
buf = bytearray(50) # create a buffer
spi.readinto(buf) # read into the given buffer (reads 50 bytes in this case)spi.readinto(buf, 0xff) # read into the given buffer and output 0xff on MOSI
spi.write(b'12345') # write 5 bytes on MOSI
buf = bytearray(4) # create a buffer
spi.write_readinto(b'1234', buf) # write to MOSI and read from MISO into the buffer
spi.write_readinto(buf, buf) # write buf to MOSI and read MISO back into buf
硬件SPI更快（高达80Mhz），但仅适用于以下引脚： MISOGPIO12 MOSI是GPIO13，SCK是GPIO14。它具有与上述bitbanging SPI类相同的方法，除了构造函数和init的引脚参数（正如固定的那样）：
from machine import Pin, SPI
hspi = SPI(1, baudrate=80000000, polarity=0, phase=0)
I2C总线 I2C驱动程序通过以下程序来实现，并可在TPYBoard v202所有引脚上工作：
from machine import Pin, I2C # construct an I2C bus
i2c = I2C(scl=Pin(5), sda=Pin(4), freq=100000)
i2c.readfrom(0x3a, 4) # read 4 bytes from slave device with address 0x3a
i2c.writeto(0x3a, '12') # write '12' to slave device with address 0x3a
buf = bytearray(10) # create a buffer with 10 bytes
i2c.writeto(0x3a, buf) # write the given buffer to the slave
深度睡眠模式 将GPIO16连接到复位引脚（HUZZAH上的RST）。可以使用以下代码进行睡眠，唤醒并检查复位原因：
import machine
# configure RTC.ALARM0 to be able to wake the device
rtc = machine.RTC()rtc.irq(trigger=rtc.ALARM0, wake=machine.DEEPSLEEP)
# check if the device woke from a deep sleepif machine.reset_cause() == machine.DEEPSLEEP_RESET:
print('woke from a deep sleep')
# set RTC.ALARM0 to fire after 10 seconds (waking the device)
rtc.alarm(rtc.ALARM0, 10000)
# put the device to sleep
machine.deepsleep()
OneWire驱动 OneWire驱动程序通过以下程序实现，并可在TPYBoard v202所有引脚上工作：
from machine import Pinimport onewire
ow = onewire.OneWire(Pin(12)) # create a OneWire bus on GPIO12
ow.scan() # return a list of devices on the bus
ow.reset() # reset the bus
ow.readbyte() # read a byte
ow.writebyte(0x12) # write a byte on the bus
ow.write('123') # write bytes on the bus
ow.select_rom(b'12345678') # select a specific device by its ROM code
DS18S20和DS18B20的驱动程序：
import time, ds18x20
ds = ds18x20.DS18X20(ow)
roms = ds.scan()
ds.convert_temp()
time.sleep_ms(750)
for rom in roms:
print(ds.read_temp(rom))
确保在数据线上放置4.7k的上拉电阻。请注意，convert_temp()每次要采样温度时都必须调用该方法。
NeoPixel驱动 使用neopixel类库：
from machine import Pin
from neopixel import NeoPixel
pin = Pin(0, Pin.OUT) # set GPIO0 to output to drive NeoPixels
np = NeoPixel(pin, 8) # create NeoPixel driver on GPIO0 for 8 pixels
np[0] = (255, 255, 255) # set the first pixel to white
np.write() # write data to all pixels
r, g, b = np[0] # get first pixel colour
对于NeoPixel的入门使用：
import esp
esp.neopixel_write(pin, grb_buf, is800khz)
APA102驱动 使用apa102类库：
from machine import Pin
from apa102 import APA102
clock = Pin(14, Pin.OUT) # set GPIO14 to output to drive the clock
data = Pin(13, Pin.OUT) # set GPIO13 to output to drive the data
apa = APA102(clock, data, 8) # create APA102 driver on the clock and the data pin for 8 pixels
apa[0] = (255, 255, 255, 31) # set the first pixel to white with a maximum brightness of 31apa.write() # write data to all pixels
r, g, b, brightness = apa[0] # get first pixel colour
对于APA102的入门使用：
import esp
esp.apa102_write(clock_pin, data_pin, rgbi_buf)
DHT驱动 DHT驱动程序通过以下代码实现，并可在TPYBoard v202所有引脚上工作：
import dhtimport machine
d = dht.DHT11(machine.Pin(4))
d.measure()d.temperature() # eg. 23 (째C)
d.humidity() # eg. 41 (% RH)
d = dht.DHT22(machine.Pin(4))
d.measure()d.temperature() # eg. 23.6 (째C)
d.humidity() # eg. 41.3 (% RH)