BPI-Leaf-S3 的GPIO1~20可以使用ADC 模/数转换器，分辨率为12bit，最大可测量0~3V电压。
使用一块电位器即可应用ADC功能，例如设计一个无极调控彩灯亮度的程序。
| Potentiometer | Board |
|---|---|
| GND | GND |
| VCC | 3V3 |
| S | GPIO1 |
MicroPython
Micropython 运行环境搭建 - Banana Pi Wiki (banana-pi.org)
在上一篇 BPI-Leaf-S3 设计按键中断程序 控制彩灯的基础上，用ADC控制彩灯当前亮度。
from machine import Pin,ADC
from neopixel import NeoPixel
from array import array
import time
import micropython
adc1 = ADC(Pin(1),atten=ADC.ATTN_11DB)
micropython.alloc_emergency_exception_buf(100)
p_48 = Pin(48, Pin.OUT)
np = NeoPixel(p_48, 1,bpp=3, timing=1)
p0 = Pin(0,Pin.IN,Pin.PULL_UP)
trig_locks = array('B',[0])
trig_timeticks_list = array('L',[0,0])
count = array('L',[0])
def p0_irq(pin):
if pin.value()==0 and trig_locks[0]==0:
trig_timeticks_list[0]=time.ticks_ms()
trig_locks[0]=1
elif pin.value()==1 and trig_locks[0]==1:
trig_timeticks_list[1]=time.ticks_diff(time.ticks_ms(),trig_timeticks_list[0])
trig_locks[0]=0
if trig_timeticks_list[1] >= 20:
count[0] = count[0] + 1
if count[0] > 8:
count[0] = 0
p0.irq(handler=p0_irq,trigger= Pin.IRQ_FALLING | Pin.IRQ_RISING )
RED = (255, 0, 0)
ORANGE = (255, 100, 0)
YELLOW = (255, 255, 0)
GREEN = (0, 255, 0)
CYAN = (0, 255, 255)
BLUE = (0, 0, 255)
PURPLE = (180, 0, 255)
WHITE = (255, 255, 255)
OFF = (0, 0, 0)
color_list = [RED,ORANGE,YELLOW,GREEN,CYAN,BLUE,PURPLE,WHITE,OFF]
while True:
adc1_read = adc1.read() # 12bit
adc1_read_mv = adc1.read_uv()/1000
adc1_read_u16 = adc1.read_u16() # 16bit
brightness = adc1_read/4095
i = color_list[count[0]]
color = (round(i[0]*brightness),round(i[1]*brightness),round(i[2]*brightness))
np[0] = color
np.write()
print(adc1_read,adc1_read_u16,adc1_read_mv,"mv",count[0],color)
time.sleep(0.1)