板载基础模块实验

1.点亮LED彩灯

让我们从点亮LED彩灯开始，进入嵌入式单片机编程的世界！

from machine import Pin, SPI
from neopixel import NeoPixel
import time

import micropython
micropython.mem_info()

pin = Pin(0, Pin.OUT)      # 设置引脚GPIO0来驱动 NeoPixels
np = NeoPixel(pin, 4)      # 在GPIO0上创建一个 NeoPixel对象，包含4个灯珠

while True:
    for n in range(4):
    	np[n] = (10, 0, 0)
    	np[n-1]=(0,10,0)
    	np[n-2]=(0,0,10)
    	np[n-3]=(10,10,10)
    	n=n+1
    	np.write()          # 写入数据
    	time.sleep_ms(350)

代码在复制粘贴后应注意语法格式。

2.无源蜂鸣器

蜂鸣器分有源蜂鸣器和无源蜂鸣器，有源蜂鸣器的使用方式非常简单，只需要接上电源，蜂鸣器就发声，断开电源就停止发声。而本实验用到的无源蜂鸣器，是需要给定指定的频率才能发声的，而且可以通过改变频率来改变蜂鸣器的发声音色，以此来判定微联开发板的PWM输出频率是在变化的。本实验的目的是通过不同频率的PWM信号输出，驱动无源蜂鸣器发出不同频率的声音，并在此基础上，通过编程让蜂鸣器播放歌曲《铃儿响叮当》。

from machine import Pin
from machine import PWM
from time import sleep_ms
class BUZZER:
def __init__(self, sig_pin):
    self.pwm = PWM(Pin(41, Pin.OUT)) 
def play(self, melodies, wait, duty): 
    for note in melodies:
        print("note:{}".format(note))
        if note:
            self.pwm.freq(note)
        self.pwm.duty(duty)
        sleep_ms(wait)
    self.pwm.duty(0)
B0 = 31
C1 = 33
CS1 = 35
D1 = 37
DS1 = 39
E1 = 41
F1 = 44
FS1 = 46
G1 = 49
GS1 = 52
A1 = 55
AS1 = 58
B1 = 62
C2 = 65
CS2 = 69
D2 = 73
DS2 = 78
E2 = 82
F2 = 87
FS2 = 93
G2 = 98
GS2 = 104
A2 = 110
AS2 = 117
B2 = 123
C3 = 131
CS3 = 139
D3 = 147
DS3 = 156
E3 = 165
F3 = 175
FS3 = 185
G3 = 196
GS3 = 208
A3 = 220
AS3 = 233
B3 = 247
C4 = 262
CS4 = 277
D4 = 294
DS4 = 311
E4 = 330
F4 = 349
FS4 = 370
G4 = 392
GS4 = 415
A4 = 440
AS4 = 466
B4 = 494
C5 = 523
CS5 = 554
D5 = 587
DS5 = 622
E5 = 659
F5 = 698
FS5 = 740
G5 = 784
GS5 = 831
A5 = 880
AS5 = 932
B5 = 988
C6 = 1047
CS6 = 1109
D6 = 1175
DS6 = 1245
E6 = 1319
F6 = 1397
FS6 = 1480
G6 = 1568
GS6 = 1661
A6 = 1760
AS6 = 1865
B6 = 1976
C7 = 2093
CS7 = 2217
D7 = 2349
DS7 = 2489
E7 = 2637
F7 = 2794
FS7 = 2960
G7 = 3136
GS7 = 3322
A7 = 3520
AS7 = 3729
B7 = 3951
C8 = 4186
CS8 = 4435
D8 = 4699
DS8 = 4978
mario = [
E7, E7, 0, E7, 0, C7, E7, 0,
G7, 0, 0, 0, G6, 0, 0, 0,
C7, 0, 0, G6, 0, 0, E6, 0,
0, A6, 0, B6, 0, AS6, A6, 0,
G6, E7, 0, G7, A7, 0, F7, G7,
0, E7, 0, C7, D7, B6, 0, 0,
C7, 0, 0, G6, 0, 0, E6, 0,
0, A6, 0, B6, 0, AS6, A6, 0,
G6, E7, 0, G7, A7, 0, F7, G7,
0, E7, 0, C7, D7, B6, 0, 0,
]
jingle = [
E7, E7, E7, 0,
E7, E7, E7, 0,
E7, G7, C7, D7, E7, 0,
F7, F7, F7, F7, F7, E7, E7, E7, E7, D7, D7, E7, D7, 0, G7, 0,
E7, E7, E7, 0,
E7, E7, E7, 0,
E7, G7, C7, D7, E7, 0,
F7, F7, F7, F7, F7, E7, E7, E7, G7, G7, F7, D7, C7, 0
]
buzzer = BUZZER(15)
buzzer.play(mario, 150, 512)
sleep_ms(1000)
print("播放 jingle bells.")
buzzer.play(jingle, 250, 512)
sleep_ms(1000)

3.RTC时钟

import time
from machine import Pin,I2C
import machine
rtc=machine.RTC()
rtc.datetime((2022,04,1,2,5,09,1,0))
while 1:
    print(rtc.datetime)
    time.sleep(1)

4.声音

from machine import I2S 
from machine import Pin, SPI
import time
"""
GPIO13 -- DIN
GPIO12 --- BCLK
GPIO14 -- LRC
GND -- GND
5V或3.3V -- VCC
"""

# 初始化引脚定义
BCLK_pin = Pin(45) # 串行时钟输出
LRCK_pin = Pin(46)  # 字时钟
SDATA_pin = Pin(42)  # 串行数据输出


audio_out = I2S(1, sck=BCLK_pin, ws=LRCK_pin, sd=SDATA_pin, mode=I2S.TX, bits=32, format=I2S.MONO, rate=16000, ibuf=20480)

wavtempfile = "download.wav"

with open(wavtempfile,'rb') as f:
    pos = f.seek(44)
    wav_samples = bytearray(100000)
    wav_samples_mv = memoryview(wav_samples)

    while True:
        try:
            num_read = f.readinto(wav_samples_mv)
            num_written = 0
            while num_written < num_read:
                num_written += audio_out.write(wav_samples_mv[num_written:num_read])
            audio_out.deinit()
        except Exception as ret:
            print("产生异常...", ret)
            break

5.摄像头

from machine import Pin
from tftlcd import LCD24
import sensor,time

########################
# 构建3.2寸LCD对象并初始化
########################
d = LCD24(portrait=1) #默认方向竖屏
KEY=Pin(0,Pin.IN,Pin.PULL_UP) #构建KEY对象

#摄像头初始化
cam = sensor.OV2640()
cam.reset()
cam.set_framesize(sensor.LCD) #240*240分辨率
cam.set_hmirror(1)
cam.set_vflip(1)
cam.display() #LCD显示

num=0 #用于命名图片
cam_flag = 0 #拍照标志位

##############################
#      USR按键  拍照并保存
##############################
def fun(KEY):
    global cam_flag
    cam_flag = 1

#中断初始化
KEY.irq(fun,Pin.IRQ_FALLING) #定义中断，下降沿触发

while True:

    #收到拍照命令
    if cam_flag == 1:

        #拍照并保存图片
        cam.snapshot("/"+str(num)+".jpg")

        num=num+1  #照片名称
        cam_flag=0 #清空标志位

6.旋转编码器

from machine import Pin
import time
KEY=Pin(0,Pin.IN,Pin.PULL_UP) #构建KEY对象
while True:
    if KEY.value()==0:   #按键被按下
        time.sleep_ms(10) #消除抖动
        if KEY.value()==0: #确认按键被按下
            print('KEY')
            while not KEY.value(): #检测按键是否松开
                pass