e-Paper Weather Clock

Use RaspberryPi, DHT-22 humidity & temperature sensor, and WeShare 4.3 inch e-Paper screen, refered by https://github.com/emptyhua/epaper_clock

Finished Product

Hardware Connection

RaspberryPi 3B's GPIO

BCM	wPi	Name	Mode	V	Physical		Physical	V	Mode	Name	wPi	BCM
		3.3v			1		2			5v
2	8	SDA.1	IN	1	3		4			5v
3	9	SCL.1	IN	1	5		6			0v
4	7	GPIO. 7	IN	1	7		8	1	ALT5	TxD	15	14
		0v			9		10	1	ALT5	RxD	16	15
17	0	GPIO. 0	IN	0	11		12	0	IN	GPIO. 1	1	18
27	2	GPIO. 2	IN	0	13		14			0v
22	3	GPIO. 3	IN	0	15		16	0	IN	GPIO. 4	4	23
		3.3v			17		18	0	IN	GPIO. 5	5	24
10	12	MOSI	ALT0	0	19		20			0v
9	13	MISO	ALT0	0	21		22	0	IN	GPIO. 6	6	25
11	14	SCLK	ALT0	0	23		24	1	OUT	CE0	10	8
		0v			25		26	1	OUT	CE1	11	7
0	30	SDA.0	IN	1	27		28	1	IN	SCL.0	31	1
5	21	GPIO.21	IN	1	29		30			0v
6	22	GPIO.22	IN	1	31		32	0	IN	GPIO.26	26	12
13	23	GPIO.23	IN	0	33		34			0v
19	24	GPIO.24	OUT	1	35		36	1	OUT	GPIO.27	27	16
26	25	GPIO.25	IN	0	37		38	0	IN	GPIO.28	28	20
		0v			39		40	0	IN	GPIO.29	29	21

Connect to e-Paper screen

E-Paper Screen	Raspberry Pi
VCC	3.3
GND	GND
DIN	MOSI
CLK	SCLK
CS	24 (Physical, BCM: CE0, 8)
D/C	22 (Physical, BCM: 25)
RES	11 (Physical, BCM: 17)
BUSY	18 (Physical, BCM: 24)

Connect to DHT-22 sensor

DHT22	Raspberry Pi
DOUT	GPIO7(BCM4)

You can connect DHT-22's DOUT to RaspberryPi's other GPIO, as long as modify the second parameter of Adafruit_DHT.read function in main.py

Install Python Library

Install the following python library

• RPi.GPIO
• spidev
• requests
• lxml
• Python Image Library(pillow)

Install DHT-22 driver

git clone https://github.com/adafruit/Adafruit_Python_DHT.git  
cd Adafruit_Python_DHT  
sudo python ./setup.py install 

Usage

1. Connect all wires
2. Install all libraries or environments needed
3. Run main.py

How to set auto-start?

Added script in /etc/rc.local(may not stable), or use systemd(recommend), following these steps:

1. Write a epaper_clock.service script

[Unit]
Description=epaper_clock
[Service]
Type=oneshot
ExecStart=#####(path of your own script)#######
[Install]
WantedBy=multi-user.target

2. Copy this script to /etc/systemd/system/multi-user.target.wants/ floder，and modify file authority using：chmod +x
3. Start service: systemctl start epaper_clock.service
4. Check sevice status: systemctl status epaper_clock.service
5. Stop sevice: systemctl stop epaper_clock.service

FAQ

1. weather source may invalid, try to change another one
2. network problem

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电子墨水屏天气时钟

使用树莓派 + DHT22温湿度传感器 + 微雪4.3寸电子墨水屏搭建的天气时钟，参考了 https://github.com/emptyhua/epaper_clock 的创意。

效果图

硬件连接

树莓派3B GPIO接口图

BCM	wPi	Name	Mode	V	Physical		Physical	V	Mode	Name	wPi	BCM
		3.3v			1		2			5v
2	8	SDA.1	IN	1	3		4			5v
3	9	SCL.1	IN	1	5		6			0v
4	7	GPIO. 7	IN	1	7		8	1	ALT5	TxD	15	14
		0v			9		10	1	ALT5	RxD	16	15
17	0	GPIO. 0	IN	0	11		12	0	IN	GPIO. 1	1	18
27	2	GPIO. 2	IN	0	13		14			0v
22	3	GPIO. 3	IN	0	15		16	0	IN	GPIO. 4	4	23
		3.3v			17		18	0	IN	GPIO. 5	5	24
10	12	MOSI	ALT0	0	19		20			0v
9	13	MISO	ALT0	0	21		22	0	IN	GPIO. 6	6	25
11	14	SCLK	ALT0	0	23		24	1	OUT	CE0	10	8
		0v			25		26	1	OUT	CE1	11	7
0	30	SDA.0	IN	1	27		28	1	IN	SCL.0	31	1
5	21	GPIO.21	IN	1	29		30			0v
6	22	GPIO.22	IN	1	31		32	0	IN	GPIO.26	26	12
13	23	GPIO.23	IN	0	33		34			0v
19	24	GPIO.24	OUT	1	35		36	1	OUT	GPIO.27	27	16
26	25	GPIO.25	IN	0	37		38	0	IN	GPIO.28	28	20
		0v			39		40	0	IN	GPIO.29	29	21

与4.3寸电子墨水屏幕的连接

E-Paper Screen	Raspberry Pi
VCC	3.3
GND	GND
DIN	MOSI
CLK	SCLK
CS	24 (Physical, BCM: CE0, 8)
D/C	22 (Physical, BCM: 25)
RES	11 (Physical, BCM: 17)
BUSY	18 (Physical, BCM: 24)

与DHT-22传感器的连接

DHT22	Raspberry Pi
DOUT	GPIO7(BCM4)

DHT-22 DOUT引脚也可以接到其他GPIO脚上，不过要相应的修改main.py中Adafruit_DHT.read函数第二个参数

Python库

安装以下库文件

• RPi.GPIO
• spidev
• requests
• lxml
• Python Image Library(pillow)

DHT22，安装厂商开源的驱动

git clone https://github.com/adafruit/Adafruit_Python_DHT.git  
cd Adafruit_Python_DHT  
sudo python ./setup.py install 

使用方法

1. 接好线
2. 安装必须的环境和库
3. 运行main.py

如何脚本设置开机启动？

方法一：在/etc/rc.local中添加执行脚本。不太稳定，经常会出现各种奇怪的情况。 方法二：使用systemd（推荐）

1. 编写epaper_clock.service脚本

[Unit]
Description=epaper_clock
[Service]
Type=oneshot
ExecStart=#####(path of your own script)#######
[Install]
WantedBy=multi-user.target

2. 将脚本拷贝到/etc/systemd/system/multi-user.target.wants/目录下，并修改文件执行权限：chmod +x
3. 启动服务 systemctl start epaper_clock.service
4. 查看服务状态 systemctl status epaper_clock.service
5. 停止服务 systemctl stop epaper_clock.service

常见问题 FAQ

1. 天气源失效，尝试换抓取页面或天气API
2. 网络连接问题