【得捷电子Follow me第1期】任务2：驱动外设

太阳上的骑士

【得捷电子Follow me第1期】任务2：驱动外设 [复制链接]

 

硬件搭建

 

由于Grove外设配的线非常长，把这些外设连在一起后看着就脑袋疼。本来想把所有接插件全卸了，设计一个底板，把所有模块全焊在底板上，看着是最好的，但是又失去了灵活搭配和可扩展性，最后想了个折中方案，把所有模块固定在一个底板上，底板在接口就近开孔，线从底板底下走，天线用双面胶粘在底板上，这样不会显得很乱。

 

 

驱动LED

导入machine.Pin类就可以控制LED亮灭，为了让LED闪烁起来，可以导入machine.Timer类，用RP2040的硬件定时器来定时触发中断回调函数，从而使LED闪烁起来。

from machine import Pin, Timer

led = Pin("LED", Pin.OUT)
tim = Timer()
def tick(timer):
    global led
    led.toggle()

tim.init(freq=2, mode=Timer.PERIODIC, callback=tick)

 

驱动蜂鸣器

蜂鸣器和LED驱动类似，只需要给高低电平即可。

import time, machine
from machine import Pin

buzzer_pin = machine.Pin(20, machine.Pin.OUT)
while True:
    buzzer_pin.value(1)
    time.sleep(0.5)
    
    buzzer_pin.value(0)
time.sleep(0.5)

 

也可以用PWM来实现更多可能性。

import time
from machine import Pin, PWM


# Construct PWM object, with LED on Pin(25).
pwm = PWM(Pin(20))

# Set the PWM frequency.
pwm.freq(1000)

# Fade the LED in and out a few times.
duty = 0
direction = 1
for _ in range(8 * 256):
    duty += direction
    if duty > 255:
        duty = 255
        direction = -1
    elif duty < 0:
        duty = 0
        direction = 1
    pwm.duty_u16(duty * duty)
time.sleep(0.001)

 

驱动OLED显示屏

OLED显示屏使用SSD1315控制器，可以用SSD1306控制器的代码库。代码库可以从GitHub下载，然后把库文件拖到芯片里，就可以在自己的py文件里使用相应功能。

import time
from machine import Pin, I2C
from ssd1306 import SSD1306_I2C

# Grove Shield For Pi Pico I2C0
i2c = I2C(0, sda=Pin(8), scl=Pin(9), freq=400000)
oled = SSD1306_I2C(128, 64, i2c)
oled.text("Hello World!", 0, 0, 1)
oled.show()

 

 

跟着直播绘制图形

from machine import Pin, I2C
from ssd1306 import SSD1306_I2C

#Grove Shield for Pi Pico I2C0
i2c = I2C(0, sda = Pin(8), scl = Pin(9), freq = 400000)
oled = SSD1306_I2C(128, 64, i2c)

oled.fill(0)
oled.fill_rect(0, 0, 32, 32, 1)
oled.fill_rect(2, 2, 28, 28, 0)
oled.vline(9, 8, 22, 1)
oled.vline(16, 2, 22, 1)
oled.vline(23, 8, 22, 1)
oled.fill_rect(26, 24, 2, 4, 1)
oled.text('MicroPython', 40, 0, 1)
oled.text('SSD1306', 40, 12 ,1)
oled.text('OLED 128x64', 40, 24, 1)
oled.show()

 

 

绘制树莓派

# Display Image & text on I2C driven ssd1306 OLED display 
from machine import Pin, I2C
from ssd1306 import SSD1306_I2C
import framebuf

WIDTH  = 128                                            # oled display width
HEIGHT = 32                                             # oled display height

i2c = I2C(0)                                            # Init I2C using I2C0 defaults, SCL=Pin(GP9), SDA=Pin(GP8), freq=400000
print("I2C Address      : "+hex(i2c.scan()[0]).upper()) # Display device address
print("I2C Configuration: "+str(i2c))                   # Display I2C config


oled = SSD1306_I2C(WIDTH, HEIGHT, i2c)                  # Init oled display

# Raspberry Pi logo as 32x32 bytearray
buffer = bytearray(b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00|?\x00\x01\x86@\x80\x01\x01\x80\x80\x01\x11\x88\x80\x01\x05\xa0\x80\x00\x83\xc1\x00\x00C\xe3\x00\x00~\xfc\x00\x00L'\x00\x00\x9c\x11\x00\x00\xbf\xfd\x00\x00\xe1\x87\x00\x01\xc1\x83\x80\x02A\x82@\x02A\x82@\x02\xc1\xc2@\x02\xf6>\xc0\x01\xfc=\x80\x01\x18\x18\x80\x01\x88\x10\x80\x00\x8c!\x00\x00\x87\xf1\x00\x00\x7f\xf6\x00\x008\x1c\x00\x00\x0c \x00\x00\x03\xc0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00")

# Load the raspberry pi logo into the framebuffer (the image is 32x32)
fb = framebuf.FrameBuffer(buffer, 32, 32, framebuf.MONO_HLSB)

# Clear the oled display in case it has junk on it.
oled.fill(0)

# Blit the image from the framebuffer to the oled display
oled.blit(fb, 96, 0)

# Add some text
oled.text("Raspberry Pi",5,5)
oled.text("Pico",5,15)

# Finally update the oled display so the image & text is displayed
oled.show()

 

 

驱动RP2040内部温度传感器

RP2040内部有温度传感器，可以将ADC输入连接到内部温度传感器，温度转换公式为：

T = 27 - (ADC_voltage - 0.706)/0.001721

实验显示温度跳动比较大，不知道是供电问题还是需要对ADC采集电压进行滤波和处理。

 

import time
from machine import Pin, I2C
from ssd1306 import SSD1306_I2C

#Grove Shield for Pi Pico I2C0
i2c = I2C(0, sda = Pin(8), scl = Pin(9), freq = 400000)
oled = SSD1306_I2C(128, 64, i2c)

sensor_temp = machine.ADC(4)
conversion_factor = 3.3 / (65536)
while True:
    reading = sensor_temp.read_u16() * conversion_factor
    temp = 27 - (reading - 0.706) / 0.001721
    oled.fill(0)
    oled.text(f'temp is {temp:.1f}', 0, 12, 1)
    oled.show()
time.sleep(0.5)

 

lugl4313820

大佬，这底板，是自己打样的吗？楼主的设计功底不错不错！