[OpenCV] moment

每次都有不同的認知
https://chtseng.wordpress.com/2017/03/24/%E4%BD%BF%E7%94%A8moments%E6%8F%8F%E8%BF%B0%E8%91%89%E7%89%87%E9%A1%9E%E5%9E%8B/
https://en.wikipedia.org/wiki/Centroid
https://en.wikipedia.org/wiki/Image_moment
https://dsp.stackexchange.com/questions/4868/contour-and-area-raw-spatial-and-central-image-moments
http://www.aishack.in/tutorials/image-moments/

[RPi] Raspberry Pi Camera Comparison

http://www.semifluid.com/2017/01/23/raspberry-pi-camera-comparison/

[OpenCV] findContours

找到這篇寫得很詳細
http://opencvpython.blogspot.tw/2013/01/contours-5-hierarchy.html

[OpenCV] 影像識別好書

英文 PDF 加中文大綱 QQ

http://www.manalhelal.com/Books/crol/Algorithms%20for%20Image%20Processing%20and%20Computer%20Vision_2011.pdf
https://www.amazon.cn/dp/B0083PY050

[課外活動] pyimagesearch

每次都找好久
https://gurus.pyimagesearch.com/courses/pyimagesearch-gurus-course/

[無線通訊] 基礎知識101

這幾篇超基礎內容需要瞭解

Understanding Spread Spectrum Modulation in RF Systems
https://www.allaboutcircuits.com/technical-articles/understanding-spread-spectrum-modulation-rf-systems/

The How and Why of Spread-Spectrum Digital Signals
https://www.allaboutcircuits.com/technical-articles/the-how-and-why-of-spread-spectrum-digital-signals/

Introduction to Software-Defined Radio
https://www.allaboutcircuits.com/technical-articles/introduction-to-software-defined-radio/

[RPi] 溫濕度感測

耶, Open Source, 都不用自己做
https://www.youtube.com/watch?v=hFqNiZ4p0Ss

[RPi] Adafruit GPS

本來以為蠻熟得, 結果還是弄了很久
https://gary-dalton.github.io/RaspberryPi-projects/rpi3_gps.html
https://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi
https://www.raspberrypi.org/forums/viewtopic.php?t=172893&p=1105715

[JavaScript] Google Map API

趕快惡補一下, 在地圖上標示幾個點
https://wrightshq.com/playground/placing-multiple-markers-on-a-google-map-using-api-3/

要顯示在 google map
google.com/maps/?q=,

google.com/maps/?q=-15.623037,18.388672

[RPi] 解決 GlobalStat BU-353-S4 亂碼問題

在 FAQ 裡寫得很清楚:

37Q) I am seeing strange characters being outputed on GPSInfo & the red LED isn't on. How can I fix this?

37A) Please follow these steps:

1. Download and install this software: http://www.usglobalsat.com/store/downloads/SiRFDemo387.zip

2. Run the Sirf Demo software.

3. Connect your device, choose the correct COM port, and select the 4800 baud rate.

4. Go to Action > Open Data Source.

5. Next, go to Action > Synchronize Protocol & baud rate.

6. Then, go to Action > Switch to NMEA Protocol.

7. In the pop-up window, select the 4800 baud rate under the Baud Rate and click Send.

8. Close the Sirf Demo software.

測試程式

import serial

ser = serial.Serial("/dev/ttyUSB0", 4800, timeout=0.5)

while True:
    try:
        str = ser.readline()
        print str
    except Exception as e:
        print(e)
        pass

如果在執行 cgps -s 以後, 再執行測試程式以後可能會變成亂碼, 一個方法就是透過上面的 GPSInfo 修改, 另一個方法就是透過指令列修改

sudo pkill gpsd
sudo stty 4800 > /dev/ttyUSB0
sudo gpsd -b /dev/ttyUSB0
cat /dev/ttyUSB0     # CTRL+c to stop

順帶一提, 這邊有不錯的範例程式
https://www.raspberrypi.org/forums/viewtopic.php?t=172893&p=1105715

reference:
* https://askubuntu.com/questions/30569/how-to-use-gps-receiver-bu-353

[Security] RF 逆向工程

Matt Knight 的演講是目前看到講得最好的一篇, 還帶實做唷

這幾篇傳說也不錯, 有空補一下吧, 從 adafruit 看到的

• All Your RFz Are Belong To Me: Hacking The Wireless World With Software-Defined Radio
• Noise Floor: Exploring Unintentional Radio Emissions
• Hacker + Airplane = No Good Can Come Of This

[閒聊] LoRa 會是未來主流嗎？

LoRa 這兩年也炒得很兇, 台北市也花了不少錢在上面, 各廠商也推出一堆模組

不過剛剛看到 TI 這篇文章, 批評 Semtech 很多

又看到 Matt Knight 的 LoRa 逆向工程批評 Semtech 文件都是假的

難道 Semtech 都不用出來負責嗎 XDD

[資訊科學] 網路通訊 101

非常好的科普, http://www.hightech.tw

[RPi] PiTFT Plus 使用腳位

雖然原廠就有寫了, 但實測之後發現使用到的腳位是實體腳位的 3,5(I2C), 19, 21, 23, 24(SPI), 4(5V),17(3.3V), 20(GND), 還有 18 和 22
https://www.adafruit.com/product/2423