树莓派RP2350-桌面动态温湿度计
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1 树莓派RP2350-桌面动态温湿度计
本文介绍了DFRobot Beetle RP2350开发板结合DHT11模块、锂电池模块、随机眨眼动画，实现OLED 显示的桌面动态温湿度计的项目设计。
2 项目介绍
本项目包括
工作原理：ADC电压采集与电量转换
工程调试：电量获取、电量图标显示、DHT11温湿度显示、OLED眨眼动画
工程代码：合并调试代码，实现完整的项目设计功能
效果演示：帧动画显示、动态展示最终实现桌面动态温湿度计的制作。
3 工作原理
根据开发板原理图可知，电池VBAT的分压电路与主控的GPIO29模拟接口相连，因此通过该引脚可实时采集监测电池电压信息，进而实现电量显示。
4 硬件连接
GP0->DATA（DHT11）
GP4->SDA（OLED）
GP5->SCL（OLED）
BAT->Battery Positive
GND->Battery Negative
5 示意图
6 工程调试
包括ADC电量采集、电量的OLED显示、DHT11温湿度数据和电量图标的显示、眨眼动画等调试项目。
7 电量获取
通过ADC 读取GPIO29 电压值并终端打印
8 代码
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1.from machine import Pin, ADC
2.import utime
3.
4.#initialize ADC pin
5.adc = ADC(Pin(29))
6.
7.#parameters for voltage divide resistor
8.R1, R2=1000000, 1000000
9.DIV_RATIO=(R1 + R2)/R1
10.
11.def get_battery_level():
12.adc_value = adc.read_u16()
13.voltage = (adc_value / 65535) * 3.3
14.actual_voltage = voltage * DIV_RATIO # voltage division compensation
15.percent=min(max((actual_voltage - 3.3) / (4.2-3.3) *100, 0), 100)
16.return percent, actual_voltage
17.
18.while True:
19.percent, voltage = get_battery_level()
20.print(‘Battery Voltage: {:.2f} V, Battery Level: {:.1f}%’.format(voltage,percent))
21.utime.sleep(1)
保存代码，连接开发板，配置解释器并运行。
9 效果
终端打印ADC 采集的电池电压值以及电量百分比
10 电量显示
OLED显示ADC采集的电量百分比。
11 代码
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1.from machine import Pin, ADC, I2C
2.import ssd1306
3.import utime
4.
5.#initialize ADC pin
6.adc=ADC(Pin(29))
7.
8.#initialize OLED
9.i2c=I2C(0, scl=Pin(5), sda=Pin(4))
10.oled=ssd1306.SSD1306_I2C(128, 64, i2c)
11.
12.#parameters of voltage divide resistor
13.R1, R2=1000000, 1000000 # 1M
14. Vref_BAT=3.9#battery voltage in full chargedstate
15.
16.def get_battery_level():
17.adc_value = adc.read_u16()
18.voltage = (adc_value / 65535) * 3.3
19.DIV_RATIO = (R1 + R2) / R1
20.actual_voltage = voltage * DIV_RATIO # voltage division compensation
21.percent=min(max((actual_voltage - 3.3) /(Vref_BAT - 3.3) * 100, 0), 100)
22.return percent, actual_voltage
23.
24.def draw_battery(percent):
25.oled.fill(0)
26.oled.text(‘{:.0f}%’.format(percent), 0, 17)
27.# draw battery cartoon icon
28.oled.rect(0, 0, 30, 15, 1) # frame (x,y,width,height)
29.oled.rect(30, 5, 3, 5, 1) # anode
30.oled.fill_rect(2, 2, int(26 * percent / 100), 11, 1) # electric percent column
31.oled.rotate(0)
32.oled.show()
33.
34.def BAT_display(percent,x,y): # battery percent,icon position (x,y)
35.oled.fill(0)
36.oled.text(‘{:.0f}%’.format(percent), 0+x, 17+y)
37.# draw battery cartoon icon
38.oled.rect(0+x, 0+y, 30, 15, 1) # frame (x,y,width,height)
39.oled.rect(30+x, 5+y, 3, 5, 1) # anode
40.oled.fi ll_rect(2+x, 2+y, int(26 * percent / 100),11, 1) # electric percent column
41.oled.rotate(0)
42.oled.show()
43.
44.def draw_vertical_battery(percent,x,y): # batterypercent, icon position (x,y)
45.oled.fi ll(0)
46.oled.text(‘{:.0f}’.format(percent), 0+x, 33+y)
47.# draw battery cartoon icon
48.oled.rect(0+x, 2+y, 15, 30, 1) # frame (x,y,width,height)
49.oled.rect(5+x, 0+y, 5, 3, 1) # anode
50.fi ll_h = int(27 * percent / 100)
51.oled.fi ll_rect(2+x, 2 + (28 - fi ll_h) + y, 11, fi ll_h, 1) # percent column
52.oled.rotate(0)
53.oled.show()
54.
55.while True:
56.percent, voltage = get_battery_level()
57.#draw_battery(percent)
58.BAT_display(percent,90,2)
59.#draw_vertical_battery(percent,90,9)
60.print(‘Battery Voltage: {:.2f} V, Battery Level:{:.1f}%’.format(voltage,percent))
61.utime.sleep(2)
保存代码，连接开发板，配置解释器并运行。
12 效果
电量图标的水平显示
电量图标的竖直显示
13 DHT11温湿度计
带电量显示的DHT11温湿度计
14 代码
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1.from machine import Pin, ADC, I2C
2.from PicoDHT22 import PicoDHT22
3.import ssd1306
4.import utime
5.
6.#initialize ADC pin
7.adc = ADC(Pin(29))
8.
9.#initialize OLED
10.i2c=I2C(0, scl=Pin(5), sda=Pin(4))
11.oled=ssd1306.SSD1306_I2C(128, 64, i2c)
12.
13.#parameters of voltage divide resistor
14.R1, R2 = 1000000, 1000000
15.Vref_BAT = 3.81 # battery voltage in full charged state
16.
17.def get_battery_level():
18.adc_value = adc.read_u16()
19.voltage = (adc_value / 65535) * 3.3
20.DIV_RATIO = (R1 + R2) / R1
21.actual_voltage = voltage * DIV_RATIO # voltage division compensation
22.percent = min(max((actual_voltage - 3.3) /(Vref_BAT - 3.3) * 100, 0), 100)
23.return percent, actual_voltage
24.
25.def draw_battery(percent):
26.oled.fill(0)
27.oled.text(‘{:.0f}%’.format(percent), 90, 27)
28.# draw battery cartoon icon
29.oled.rect(90, 10, 30, 15, 1) # frame
30.oled.rect(120, 15, 3, 5, 1) # anode
31.oled.fill_rect(92, 12, int(26 * percent / 100),11, 1) # electric percent column
32.oled.show()
33.
34.def BAT_display(percent):
35.oled.fill(0)
36.oled.text(‘{:.0f}%’.format(percent), 90, 27)
37.# draw battery cartoon icon
38.oled.rect(90, 10, 30, 15, 1) # frame
39.oled.rect(120, 15, 3, 5, 1) # anode
40.oled.fill_rect(92, 12, int(26 * percent / 100), 11, 1)
41.oled.show()
42.
43.def draw_vertical_battery(percent,x,y):
44.#局部清屏并显示电量百分比
45.oled.fill_rect(x,y,15+8,30+16,0)
46.oled.text(‘{:.0f}’.format(percent), 0+x, 33+y)
47.#竖版电池绘制
48.oled.rect(0+x, 2+y, 15, 30, 1) # frame (x,y,width,height)
49.oled.rect(5+x, 0+y, 5, 3, 1) # anode
50.fill_h = int(26 * percent / 100)
51.oled.fill_rect(2+x, 2 + (28 - fill_h) + y, 11, fill_h, 1) # percent column
52. oled.rotate(0)
53. oled.show()
54.
55. def display_TH(temp,humi):
56.oled.fill_rect(20,15,6*8,64-15,0) #局部清屏
57.oled.text(“Temperature:”, 0, 0)
58.oled.text(“{:.1f} C”.format(temp), 20, 15)
59.oled.text(“Humidity:”, 0, 35)
60.oled.text(“{:.1f} %”.format(humi), 20, 50)
61.oled.rotate(0) # rotate the screen display for amore comfortable position
62.oled.show()
63.
64.dht_sensor=PicoDHT22(Pin(0,Pin.IN,Pin.PULL_UP),dht11=True)
65.while True:
66. emp,humi = dht_sensor.read()
67.percent, voltage = get_battery_level()
68.#draw_battery(percent)
69.#BAT_display(percent)
70.draw_vertical_battery(percent,90,16)
71.display_TH(temp,humi)
72.print(‘Battery Voltage: {:.2f} V, Battery Level:{:.1f}%’.format(voltage,percent))
73.utime.sleep(2)
15 效果
电量和温湿度显示，数据刷新的时间间隔为2秒
16 眨眼动画
OLED显示矩形填充状眼睛，改变形状并利用人眼的视觉暂留效应实现眨眼效果。
17 代码
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1.from machine import Pin, I2C
2.import ssd1306
3.import utime
4.import urandom
5.
6.i2c = I2C(0, scl=Pin(5), sda=Pin(4))
7.oled_width = 128
8.oled_height = 64
9.oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
10.
11.def draw_eyes(state,xshift,yshift):
12.“””state: 0=完全睁开, 1=半闭, 2=完全闭上”””
13.width,height = (int)(oled_width/5),(int)(oled_height/3)
14.cx,cy=(int)((oled_width-2.5*width)/2),(int)((oled_height-height)/2) # eyes at scrren center 定
位点为矩形左上角
15.x=cx+xshift
16.y=cy+yshift
17.oled.fill_rect(x, y, int(2.5*width), height, 0)
18.#draw left eye
19.if state == 0: # 完全睁开
20.oled.fill_rect(x, y, width, height, 1)
21.elif state == 1: # 半闭
22.oled.fill_rect(x, y+(int)(height/4), width,(int)(height/2), 1)
23.else: # 完全闭上
24.oled.hline(x, y+(int)(height/2), width, 1)
25.# draw right eye
26.if state == 0: # 完全睁开
27.oled.fill_rect(x+width+(int)(width/2), y, width, height, 1)
28.elif state == 1: # 半闭
29.oled.fill_rect(x+width+(int)(width/2), y+(int)(height/4), width, (int)(height/2), 1)
30.else: # 完全闭上
31.oled.hline(x+width+(int)(width/2), y+(int)(height/2), width, 1)
32.oled.show()
33.
34.def blink_eyes(xshift,yshift):
35.#睁眼状态保持
36.draw_eyes(0,xshift,yshift)
37.utime.sleep(1)
38.#眨眼动画序列
39.draw_eyes(1,xshift,yshift) # 半闭
40.utime.sleep(0.1)
41.draw_eyes(2,xshift,yshift) # 全闭
42.utime.sleep(0.1)
43.draw_eyes(1,xshift,yshift) # 半闭
44.utime.sleep(0.1)
45.draw_eyes(0,xshift,yshift) # 全开
46.
47.def random_eyes():
48.xshift = urandom.randint(-(int)(oled_width/4),(int)(oled_width/4))
49.yshift = urandom.randint(-(int)(oled_height/3),(int)(oled_height/3))
50.oled.fill(0)
51.blink_eyes(xshift,yshift)
52.#print(xshift,yshift)
53.
54.while True:
55.random_eyes()
56.#blink_eyes(0,0)
保存代码，连接开发板，配置解释器并运行。
18 效果
眨眼效果（眼睛位置在屏幕内随机移动）
19 工程代码
将工程调试的代码合并，实现温湿度数据（包括电池电量）与息屏随机眨眼动画的切换显示。
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1.from machine import Pin, ADC, I2C
2.from PicoDHT22 import PicoDHT22
3.import ssd1306
4.import utime
5.import urandom
6.
7.#initialize ADC pin
8.adc=ADC(Pin(29))
9.
10.#initialize OLED
11.i2c=I2C(0, scl=Pin(5), sda=Pin(4))
12.oled_width=128
13.oled_height=64
14.oled=ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
15.
16.#parameters of voltage divide resistor
17.R1, R2=1000000, 1000000
18.Vref_BAT=3.81 # battery voltage in full charged state
19.
20.def get_battery_level():
21.adc_value=adc.read_u16()
22.voltage=(adc_value / 65535) * 3.3
23.DIV_RATIO=(R1+R2)/R1
24.actual_voltage=voltage*DIV_RATIO#voltage division compensation
25.percent=min(max((actual_voltage-3.3) /(Vref_BAT-3.3) *100, 0),100)
26.return percent, actual_voltage
27.
28.def draw_vertical_battery(percent,x,y):
29.# 局部清屏并显示电量百分比
30.oled.fill_rect(x,y,15+8,30+16,0)
31.oled.text(‘{:.0f}’.format(percent), 0+x, 33+y)
32.# 竖版电池绘制
33.oled.rect(0+x, 2+y, 15, 30, 1) # frame (x,y,width,height)
34.oled.rect(5+x, 0+y, 5, 3, 1) # anode
35.fill_h=int(26 * percent / 100)
36.oled.fill_rect(2+x, 2 + (28 - fill_h) + y, 11, fill_h, 1) # percent column
37.oled.rotate(0)
38.oled.show()
39.
40.def display_TH(temp,humi):
41.oled.fill_rect(20,15,6*8,64-15,0) # part clear
42.oled.text(“Temperature:”, 0, 0)
43.oled.text(“{:.1f} C”.format(temp), 20, 15)
44.oled.text(“Humidity:”, 0, 35)
45.oled.text(“{:.1f} %”.format(humi), 20, 50)
46.oled.rotate(0) # rotate the screen display for amore comfortable position
47.oled.show()
48.
49.def draw_eyes(state,xshift,yshift):
50.“””state: 0=full open, 1=half open, 2=close”””
51.width,height = (int)(oled_width/5),(int)(oled_height/3)
52.cx,cy = (int)((oled_width-2.5*width)/2),(int)((oled_height-height)/2) # eyes at scrren center
53.x=cx+xshift
54.y=cy+yshift
55.oled.fill_rect(x, y, int(2.5*width), height, 0)
56.#draw left eye
57.if state==0: # full open
58.oled.fill_rect(x, y, width, height, 1)
59.elif state == 1: # half open
60.oled.fill_rect(x, y+(int)(height/4), width,(int)(height/2), 1)
61.else: # close
62.oled.hline(x, y+(int)(height/2), width, 1)
63.#draw right eye
64.if state==0: # full open
65.oled.fill_rect(x+width+(int)(width/2), y, width, height, 1)
66.elif state == 1: # half open
67.oled.fill_rect(x+width+(int)(width/2), y+(int)(height/4), width, (int)(height/2), 1)
68.else: # close
69.oled.hline(x+width+(int)(width/2), y+(int)(height/2), width, 1)
70.oled.show()
71.
72.def blink_eyes(xshift,yshift):
73.#keep opening
74.draw_eyes(0,xshift,yshift)
75.utime.sleep(0.5)
76.# blink eyes order
77.draw_eyes(1,xshift,yshift) # half open
78.utime.sleep(0.1)
79.draw_eyes(2,xshift,yshift) # close
80.utime.sleep(0.1)
81.draw_eyes(1,xshift,yshift) # half open
82.utime.sleep(0.1)
83.draw_eyes(0,xshift,yshift) # full open
84.utime.sleep(0.5)
85.
86.def random_eyes():
87. xshift = urandom.randint(-(int)(oled_width/4),(int)(oled_width/4))
88.yshift = urandom.randint(-(int)(oled_height/3),(int)(oled_height/3))
89.oled.fill(0)
90.blink_eyes(xshift,yshift)
91.#print(xshift,yshift)
92.
93.dht_sensor = PicoDHT22(Pin(0,Pin.IN,Pin.PULL_UP),dht11=True)
94.def TH_BAT():
95.‘’’ temperature and humidity and battery ‘’’
96.temp,humi = dht_sensor.read()
97.percent, voltage = get_battery_level()
98.oled.fill(0)
99.display_TH(temp,humi)
100.draw_vertical_battery(percent,90,16)
101.print(‘Temperature: {:.2f} C, Humidity: {:.2f} RH, Battery Voltage: {:.2f} V, Battery Level: {:.1f}%’.format(temp,humi,voltage,percent))
102.utime.sleep(2)
103.
104.while True:
105.TH_BAT()
106.random_eyes()
连接开发板，配置解释器，将代码保存至根目录，取下数据线，连接电池，实现显示效果。
20 效果
帧动画分别如下
21 总结
本文介绍了树莓派RP2350开发板结合DHT11模块、锂电池模块、随机眨眼动画，实现OLED显示的桌面动态温湿度计的项目设计。通过多任务结合，为更多DIY设计提供了可能，如添加按键扫描或语音控制模块，实现指定的功能切换与人机交互，拓展和丰富了该开发板在物联网领域的创新与应用，为RP2350 的开发设计和产品应用提供了参考。
（本文来源于《EEPW》202506）
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