The document describes how to create a LED rollsign display using a Raspberry Pi and RGB LED matrix panel to scroll through images of Wapuu characters. Key steps include collecting Wapuu images, arranging them horizontally, connecting the LED panel to a Raspberry Pi with an RGB Matrix HAT, and writing a Python script to retrieve the image number from a WordPress page and display the corresponding image on the panel. The display can then be run automatically on startup by adding the script to the Raspberry Pi's crontab.

1. LEDパネルで
光るわぷーを
Create LED lightened Wapuu

2. 自己紹介
Self Introduce
‣
‣
http://www.yuriko.net/
@lilyfanjp

3. 架空鉄道の同人誌は売れない
Sales of imaginary railway books are very small.

4. LED方向幕を展示
Displayed LED rollsign

5. ラズパイで制御
Controlled by Raspberry Pi
Raspberry Pi +
RGB Matrix HAT
Switching PSU
Power Tap

6. “一般的なご家庭には
必ずあるラズパイ”
“At least one RPi in a ordinary home ”
逸般的な誤家庭
none-ordinary & odd home

7. LED方向幕は
自作できる
You can make a LED rollsign

8. Hardware

9. LED Matrix Panel
Signal (in) Next to

10. Raspberry Pi
Pin Header (to HAT)
HDMI
4x
USB

11. RGB Matrix HAT
To LED Panel

12. 横長パネルを縦接続
Connect landscape panels vertically

13. 黒テープで補強
Reinforce by black tape
表から見て
面が うこと
Faces are uniformed.

14. ブックスタンドに貼る
Fix on book stands by magnet
背面の磁石
Magnets on Panel back

15. Attention!

16. Software

17. Raspbian

18. RPi RGB LED Matrix

19. OS set up
git libgraphicsmagick++-dev libwebp-dev

20. Get Lib & Make
$ git clone https://github.com/hzeller/rpi-rgb-led-matrix
$ cd rpi-rgb-led-matrix
$ make -C examples-api-use
$ cd utils
$ make led-image-viewer

21. Demo
$ cd example-api-use
$ sudo ./demo
--led-gpio-mapping=adafruit-hat
--led-no-hardware-pulse
--led-chain=4 -L
-D 0

22. わぷー表示
Show wapuu

23. Create DATA

24. わぷー画像を収集
Collect wapuu images

25. 横に並べる
Arrange them

26. Scroll images
$ sudo ./demo
--led-gpio-mapping=adafruit-hat
--led-no-hardware-pulse
--led-chain=4 -L
-D 1 ../../images/wapuu.ppm

27. Demo

28. Auto Run
$ crontab -e
@reboot /home/pi/startup.sh

29. HAT Detection
#!/bin/sh
prod_path="/proc/device-tree/hat/product"
if test -f $prod_path; then
product=$(cat $prod_path)
case $product in
"Adafruit RGB Matrix + RTC HAT - HUB75 / DS1307") ./wapuu.sh;;

30. Run scroll demo
sudo ./demo
--led-gpio-mapping=adafruit-hat
--led-no-hardware-pulse
--led-chain=4 -L
-D 1 ../../images/wapuu.ppm

31. 表示の止め方
How to stop
$ ssh pi@led.local
ps auwx
sudo kill NNNN

32. ワンライナー
one liner script

33. Select by API

34. WP API で表示変更

35. http://wp.yuriko.net
/wp-json/wp/v2/pages/60

36. Response
{"id":60,"date":"2017-09-02T13:45:54",
"date_gmt":"2017-09-02T04:45:54",
"guid":{"rendered":"http://wp.yuriko.net/?page_id=60"},
"modified":"2017-09-02T15:12:12",
"modified_gmt":"2017-09-02T06:12:12",
"slug":"selected",
"status":"publish",
"type":"page",
"link":"http://wp.yuriko.net/selected/",
"title":{"rendered":"Selected"},
"content":{"rendered":"<p>001</p>n","protected":false},
"excerpt":{"rendered":"<p>001</p>n","protected":false},
"author":1,
"featured_media":0,
"parent":0,
"menu_order":0,
"comment_status":"closed",
"ping_status":"closed",
"template":"",
"meta":[],
"_links":{
"self":[{"href":"http://wp.yuriko.net/wp-json/wp/v2/pages/60"}],
"collection":[{"href":"http://wp.yuriko.net/wp-json/wp/v2/pages"}],
"about":[{"href":"http://wp.yuriko.net/wp-json/wp/v2/types/page"}],
"author":[{"embeddable":true,"href":"http://wp.yuriko.net/wp-json/wp/v2/users/
1"}],
"replies":[{"embeddable":true,"href":"http://wp.yuriko.net/wp-json/wp/v2/
comments?post=60"}],
"version-history":[{"href":"http://wp.yuriko.net/wp-json/wp/v2/pages/60/
revisions"}],
"wp:attachment":[{"href":"http://wp.yuriko.net/wp-json/wp/v2/media?parent=60"}],
"curies":[{"name":"wp","href":"https://api.w.org/{rel}","templated":true}]
}}
"content":{
"rendered":"<p>001</p>n",
"protected":false
},

37. 画像番号の取得
#/usr/bin/python
import urllib
import json
import re
import glob
import commands
import time
api = "http://wp.yuriko.net/wp-json/wp/v2/pages/60"
image_dir = "/home/lily/led/images/wapuu/"
viewer = "/home/lily/led/rpi-rgb-led-matrix/utils/
led-image-viewer "
opt = "--led-no-hardware-pulse --led-chain=4"
+ "-L --led-brightness=50 -f "

38. APIアクセス
while True:
result = None
try:
result = urllib.urlopen( api ).read()
except ValueError:
print "API Access Failed."
data = json.loads( result )
content = data["content"]["rendered"]
matchOB = re.match( r'<p>(.*)</p>', content)
if not matchOB:
continue

39. 番号抽出して画像表示
number = matchOB.group(1)
files = glob.glob(
image_dir + number + "-*.png" )
if len(files) < 1:
continue
commands.getoutput(
"sudo "+viewer+opt+files[0] )

40. TODO

41. WordCamp Tokyo 2017
のLTに登壇
Speech at WordCamp Tokyo 2017 LT
2017-09-16