[RPi] QR Code

先參考這幾篇吧
https://github.com/krystianpaszek/qrcode_scanner
https://blog.callmewhy.com/2016/04/23/opencv-find-qrcode-position/

[RPi] FCC

https://fccid.io/2ABCB-RPI32

https://www.element14.com/community/thread/56140/l/which-versions-of-raspberry-pi-are-ce-compliant-where-do-i-find-the-ce-declaration-of-conformity-on-this-site?displayFullThread=true

[Python] multi-threading programming

帶範例:
http://www.dabeaz.com/usenix2009/concurrent/
https://pymotw.com/2/threading/

介紹 join
http://stackoverflow.com/questions/15085348/what-is-the-use-of-join-in-python-threading

有哪些模組可用
http://stackoverflow.com/questions/1190206/threading-in-python

補充:
https://stackoverflow.com/questions/680684/multi-cpu-multi-core-and-hyper-thread

[RPi] Websocket

有趣的文章, websocketd 可以在 Pi 上跑, 是用 Go 寫的

[Python] Hello World D3 + Python

https://github.com/cranmer/flask-d3-hello-world

[Pyhon] multi-core programming

https://p16.praetorian.com/blog/multi-core-and-distributed-programming-in-python
http://stackoverflow.com/questions/1190206/threading-in-python

[RPi] Pulse Sensor

這有視覺化的範例程式
https://tutorials-raspberrypi.com/raspberry-pi-heartbeat-pulse-measuring/

[OpenCV] 相機校正

這個系列寫得很好
http://silverwind1982.pixnet.net/blog/post/134551091
http://silverwind1982.pixnet.net/blog/post/153218861
http://silverwind1982.pixnet.net/blog/post/229389799

[DIY] 做做AI，造造人

舊文章, 希望有時間看
http://www.diy-robots.com/

[Tips] AWS設定IP + 設定 LAMP 權限 + vsFTPd

反正就是先開好 instance

接著在 EC2 控制面板左側選擇 Network & Security > Elastic IPs

然後就下一步下一步, 就會取得一個 public IP, 中間應該要 associate 看到哪一個 instance

對了還要記得在 Security Groups 裡面選 inbound rules 才行

怎麼和我印象用 ec2-public-ip.compute1.amazonaws.com 不一樣？


設定權限其實就照這一篇就很清楚了
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/install-LAMP.html

$ sudo groupadd www
$ sudo usermod -a -G www ubuntu
$ exit
re-login
$ sudo chown -R root:www /var/www
$ find /var/www -type d -exec sudo chmod 2775 {} \;


vsFTPd 作法就參考這一篇吧
http://stackoverflow.com/questions/4723023/vsftpd-error-listing-directories

也可以切換目錄, 就修改 chroot 相關的地方吧
listen=YES
anonymous_enable=NO
local_enable=YES
write_enable=YES
local_umask=022
use_localtime=YES
xferlog_enable=YES
connect_from_port_20=YES
xferlog_file=/var/log/vsftpd.log
xferlog_std_format=YES
chroot_local_user=YES
allow_writeable_chroot=YES
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd.chroot_list
pam_service_name=ftp
pasv_enable=YES
pasv_min_port=4242
pasv_max_port=4243
port_enable=YES
pasv_address=X.X.X.X
pasv_addr_resolve=no

[OpenCV] Introduction to Computer Vision

為什麼別人十年前的教材就可以寫得這麼好？
http://www.cse.psu.edu/~rtc12/CSE486/

[RPi] Streaming

超簡單 streaming (會延遲約 10s)

On the pi:
raspivid -t 0 -o - | nc -l -p 2222
(-p: choose any port higher than 1023)

In VLC: open network stream:
tcp://192.168.2.2:2222
add in options: :demux=h264
ex: vlc tcp://192.168.2.2:2222 :demux=h264 :file-caching=100

reference:
* https://www.groovypost.com/howto/change-vlc-streaming-buffer/
* https://hmbd.wordpress.com/2016/08/01/raspberry-pi-video-and-audio-recording-and-streaming-guide/