2025/01/01

How to use / navigate this blog

This is a quick summary of how to use / navigate this blog.

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Sep. 24, 2018: The broken HTML Sitemap has been fixed. Hope it will help you find what you need faster...

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2020/02/18

Raspberry Pi - Add support for power on / off button

This post is a quick write up of me following the instruction here to create an on/off button for switching on/off the PI. When the PI is running, connecting GPIO3 to GND will cause the system to send out the sudo shutdown -h now command to switch off the PI. When the PI is not running, connecting GPIO3 to GND will cause the PI to wake up and start running.

***IMPORTANT!! This is extremely important to shut down the PI using the sudo shutdown -h now command to avoid corrupting the file system of the SD Card. If you experience trouble booting the PI after a sudden power outage, chances are the SD file system is corrupted and you will have to write a new Raspbian image to the SD Card and re-configure the Raspbian if a backup image is not available ***


2020/02/17

Raspberry Pi - Headless installation of Raspbian OS on Raspberry Pi Zero W

This post is about how to install Raspbian OS onto Raspberry Pi Zero W headlessly (without physically attaching monitor, keyboard, and mouse to the Pi Zero W).

Download OS Image

Download the OS image from the link below.

https://www.raspberrypi.org/downloads/raspbian/

For my application, I use the lite version.


Raspberry Pi - How to run a program on startup

This is a quick write up of me following the instruction here to test out how to use the GPIO of Raspberry Pi and make a program to auto-execute on startup.

Wiring Diagram

Wire up the Pi with an LED and a resistor as shown below.


Raspberry Pi - How to mount an USB Flash Drive

This is a quick write up of me following the instruction below on how to mount an USB Flash Drive to my Raspberry Pi.

How To Mount A USB Flash Disk On The Raspberry Pi
https://www.raspberrypi-spy.co.uk/2014/05/how-to-mount-a-usb-flash-disk-on-the-raspberry-pi/


2020/02/03

Seeing LoRa transmission in action using a RTL-SDR dongle and SDR# software

In this post, I use a RTL-SDR dongle and SDR# software to watch the transmission of LoRa signal at 433MHz. For info. on how to set up the RTL-SDR, please refer to the post below.

https://wei48221.blogspot.com/2020/02/how-to-setup-rtl-sdr-dongle-to-work.html

2020/02/02

How to setup an RTL2832U DVB dongle as RTL-SDR to work with SDR# (SDR Sharp)

This post is a quick record of how I set up an RTL2832U DVB dongle similar to the one shown below as RTL-SDR to work with SDR# by following the instruction at https://www.rtl-sdr.com/rtl-sdr-quick-start-guide/.

OS: Windows 8.1.