Category Archives: Tools

reMarkable 2: One Highly Customisable New Toy

Got the budget on my birthday, and the Black Friday deal was not bad, so I finally got a new toy: the reMarkable 2. 😂

reMarkable 2
reMarkable 2

Before I got this tablet, several guys recommended this to me, and what finally convinced me to buy it was no more than its extreme paper-like writing, thinness, lightness, design, etc. But after I experienced this reMarkable 2, I found its usefulness and customizability were totally beyond my expectation. The most surprising thing is that reMarkable OS is based on Linux and the manufacturer generously exposes the SSH port and root password.

During the year-end holiday, I went through this tablet a lot and would take notes with this post.

Functionality Completeness

Language Issues

The reMarkable 2 does not support non-Latin characters, so CJK (Chinese, Japanese, and Korean) characters are displayed as squares, as below.

Squares
Squares

One compromised solution is to use PDF only if possible, but we still need to ensure that all the necessary fonts are embedded in the PDF documents. If any CJK characters apply fonts not embedded in the documents, they will still be displayed as squares.

Luckily, the OS of reMarkable is based on Linux, and the SSH and the root password are available, so we can easily install the CJK fonts. Take this page as a reference for installing the RMPKG.

cd /tmp;
wget https://files.davisr.me/projects/rcu/download-fontrmpkg/NotoSansCSFont.rmpkg
wget https://files.davisr.me/projects/rcu/download-fontrmpkg/NotoSansCTFont.rmpkg
wget https://files.davisr.me/projects/rcu/download-fontrmpkg/NotoSansJPFont.rmpkg
wget https://files.davisr.me/projects/rcu/download-fontrmpkg/NotoSansKRFont.rmpkg
chmod +x *.rmpkg
./NotoSansCSFont.rmpkg --install
./NotoSansCTFont.rmpkg --install
./NotoSansJPFont.rmpkg --install
./NotoSansKRFont.rmpkg --install
rm -f *.rmpkgCode language: Bash (bash)

And the Noto Sans font can support CJK characters now.

Type Diversity

The reMarkable 2 only natively supports PDF and EPUB, but more is needed. Toltec, this community-maintained repository of free software for the reMarkable tablet, helps. With Toltec, we can install KOReader into reMarkable 2. Thanks to the powerful format compatibility, we can read documents in almost all major formats with the reMarkable 2.

## Use opkg to install remux and koreader after installing the Toltec
opkg update
opkg upgrade
# remux
# Launcher that supports multi-tasking applications 
opkg install remux
# KOReader
# Ebook reader supporting PDF, DjVu, EPUB, FB2, and many more formats
opkg install koreaderCode language: Bash (bash)

There is one thing that needs to be highlighted. The shelves of the reMarkable and KOReader do not share; we can surely use cloud storage to solve this. I will share this later. Before installing the Toltec, please ensure that the current Toltec release can support the OS version of your reMarkable tablet.

The Toltec repository includes lots of exciting software. Take your time to go through it if you are interested.

Article Management and Document Management

The reMarkable provides a browser extension. With this extension, users can convert web pages into EPUB documents and put them on the reMarkable’s shelf with one click. It is really convenient, but it is hard for me to get used to it.

  1. The format of the EPUB document content converted by the extension looks strange.
  2. Years of using Pocket as a read-it-later application make me not plan to switch to reMarkable. And I don’t want to put all my saved web pages on the reMarkable’s shelf.

So I started automating pushing the saved pages from Pocket to reMarkable, and I recalled n8n, an open workflow automation platform.

I heard about n8n before, and I tried this time and found it was really convenient. I deployed n8n on the NAS, then created this workflow quickly. You may see that the UI of workflow on n8n is really visual and user-friendly.

Pocket 2 Google Drive
Pocket 2 Google Drive

I use a scheduler to trigger the workflow below.

  1. Get the saved timestamp of the last run, and retrieve the pages saved after the last run. The API for retrieving the saved pages has an optional parameter: since. With this parameter, Pocket will only return items modified since the given UNIX timestamp.
  2. If the list is not empty, the workflow will use the OneSimpleAPI to convert the web pages into PDF documents and upload them to Google Drive one by one.
  3. Update the saved timestamp to present.

The above workflow nodes of OneSimpleAPI and Google Drive are natively supported by the n8n and are very easy to call.

These tips may reduce some of the confusion when you are creating a similar workflow:

  1. The since parameter of Pocket API uses the last modified time as a reference. If you would like to push some outdated saved pages to Google Drive, you just need to make a slight change to them, such as tag modification and resaving it again, and these pages will be pushed to Google Drive.
  2. When you trigger a deletion of a saved page, Pocket will update the status of this page to 2 before the page is totally removed. So please ensure all the saves whose status is 2 will be filtered out to prevent unnecessary uploading.

The Google Drive node supports two authentication methods: OAuth 2 and ServiceAccount. OAuth 2 requires that your callback URL contains a domain name other than an IP. For security, my NAS blocks all direct external access and only allows VPN access, so I have not bound my NAS to any domain name. So anyone whose NAS is in the same situation as mine, please prefer ServiceAccount. Primarily the service account is not your Gmail account, so please grant the R/O permission to the Google Drive folder of your reMarkable documents to the service account.

Permissions Granted to Service Account
Permissions Granted to Service Account

Actually, I can directly push the documents onto the reMarkable shelf, but I don’t think this is a good idea. The limitation of documents’ count on the reMarkable shelf can help me focus more on the current readings before I pick new readings from Google Drive. I will not let too many documents mess up my reMarkable shelf.

As I mentioned, the shelves of KOReader and reMarkable 2 don’t share, so using Google Drive to store my pending readings can make the shelves tidier. It is also easy for KOReader and reMarkable 2 to retrieve the documents wirelessly.

Publication management

Ages before, I started to use Calibre to manage publications, such as novels, books, comics, papers, etc. Then I moved the library of Calibre to NAS and ran Calibre Web in a Docker container so that I could manage the publications from any device.

Calibre Web is not an official product of Calibre, and there is more than one fork on GitHub. I prefer the image managed by linuxserver.io. If you have never used Calibre before deploying Calibre Web, you will need a new library file (metadata.db) to initiate the configuration. You can install Calibre to create a library or download it from here.

Besides the publication management via web UI, Calibre Web also supports the OPDS catalog.

The Open Publication Distribution System (OPDS) Catalog format is a syndication format for electronic
publications based on Atom and HTTP. OPDS Catalogs enable the aggregation, distribution, discovery,
and acquisition of electronic publications.

OPDS Catalogs use existing or emergent open standards and conventions, with a priority on simplicity.

OPDS Catalog 1.2

In this way, I can search for publications from the OPDS catalog.

# curl --user {username}:{password} "http://{IP}:{port}/opds/search/{queryString}"
curl --user username:password "http://{IP of NAS}:8083/opds/search/root%20cause"Code language: Bash (bash)

If items exist, the OPDS catalog will send an XML containing publication information, including book names and links, as a response.

<?xml version="1.0" encoding="UTF-8"?>
<feed
  xmlns="http://www.w3.org/2005/Atom"
  xmlns:dc="http://purl.org/dc/terms/"
  xmlns:dcterms="http://purl.org/dc/terms/">
  <id>urn:uuid:2853dacf-ed79-42f5-8e8a-a7bb3d1ae6a2</id>
  <updated>2022-12-29T16:23:55+00:00</updated>
  <link rel="self"
        href="/opds/search/root cause?"
        type="application/atom+xml;profile=opds-catalog;type=feed;kind=navigation"/>
  <link rel="start"
        href="/opds"
        type="application/atom+xml;profile=opds-catalog;type=feed;kind=navigation"/>
  <link rel="up"
        href="/opds"
        type="application/atom+xml;profile=opds-catalog;type=feed;kind=navigation"/>
  <link rel="search"
      href="/opds/osd"
      type="application/opensearchdescription+xml"/>
  <link type="application/atom+xml" rel="search" title="Search" href="/opds/search/{searchTerms}" />
  <title>Calibre-Web</title>
  <author>
    <name>Calibre-Web</name>
    <uri>https://github.com/janeczku/calibre-web</uri>
  </author>
  <entry>
    <title>Root Cause Analysis Handbook</title>
    <id>urn:uuid:06a66a9a-59d4-415b-a472-a413b8cf923d</id>
    <updated>2022-12-22T07:56:20+00:00</updated>
    <author>
      <name>ABS Consulting</name>
    </author>
    <publisher>
      <name>Rothstein Publishing</name>
    </publisher>
    <dcterms:language>eng</dcterms:language>
    <category scheme="http://www.bisg.org/standards/bisac_subject/index.html"
              term="Business &amp; Economics"
              label="Business &amp; Economics"/>
    <summary>Are you trying to improve performance, but find that the same problems keep getting in the way? Safety, health, environmental quality, reliability, production, and security are at stake. You need the long-term planning that will keep the same issues from recurring. Root Cause Analysis Handbook: A Guide to Effective Incident Investigation is a powerful tool that gives you a detailed step-by-step process for learning from experience. Reach for this handbook any time you need field-tested advice for investigating, categorizing, reporting and trending, and ultimately eliminating the root causes of incidents. It includes step-by-step instructions, checklists, and forms for performing an analysis and enables users to effectively incorporate the methodology and apply it to a variety of situations. Using the structured techniques in the Root Cause Analysis Handbook, you will: Understand why root causes are important. Identify and define inherent problems. Collect data for problem-solving. Analyze data for root causes. Generate practical recommendations. The third edition of this global classic is the most comprehensive, all-in-one package of book, downloadable resources, color-coded RCA map, and licensed access to online resources currently available for Root Cause Analysis (RCA). Called by users &#34;the best resource on the subject&#34; and &#34;in a league of its own.&#34; Based on globally successful, proprietary methodology developed by ABS Consulting, an international firm with 50 years&#39; experience in 35 countries. Root Cause Analysis Handbook is widely used in corporate training programs and college courses all over the world. If you are responsible for quality, reliability, safety, and/or risk management, you&#39;ll want this comprehensive and practical resource at your fingertips. The book has also been selected by the American Society for Quality (ASQ) and the Risk and Insurance Society (RIMS) as a &#34;must have&#34; for their members.</summary>
    <link type="image/jpeg" href="/opds/cover/30" rel="http://opds-spec.org/image"/>
    <link type="image/jpeg" href="/opds/cover/30" rel="http://opds-spec.org/image/thumbnail"/>
    <link rel="http://opds-spec.org/acquisition" href="/opds/download/30/pdf/"
          length="24812876" mtime="2022-12-22T07:56:20+00:00" type="application/pdf"/>
  </entry>
</feed>Code language: HTML, XML (xml)

Based on this, I created the workflow below to upload the document I need to Google Drive automatically.

Query the books and upload the needed books to Google Drive.
Search for the book and upload the needed books to Google Drive.

I use the Webhook node to pass the query string to the OPDS catalog to search for the publications.

Others

There are many functionalities worth going through on reMarkable, such as templates. I am amazed by the completion of reMarkable’s support for PDF, especially the support for the internal links. Many E-ink tablets almost don’t support internal links in PDF documents. Even to support some significant internal links such as tables of contents, they compromise toggle a menu to help users locate the pages instead of jumping during the document reading.

So we can generate templates with reCalendar. This template can help us plan and summarize in a year-month-day dimension. To prevent loading too long, the timespan of the preview below is only two months. You can also tweak the template by adding special dates, modifying the timespan, etc., with reCalendar.

Loader Loading…
EAD Logo Taking too long?

Reload Reload document
| Open Open in new tab

Here is all about reMarkable 2 I learned. I will keep digging and will share more. 😁

Talking about Device Management and Multi-computer Management: Is Wireless Always More Convenient than Wiredness?

As a former CS student and an ITer, the computer has become an inevitable part of my life. And also how to well manage the computers and peripherals is always a changing problem.

Why does this problem keep changing?

Environments Decide the Requirements

When I was in university, what I could control was just a tiny desk in the dormitory. So at that moment, I hoped all the peripherals would be slim and wireless so I could quickly put the mouse and keyboard into the drawer without unplugging the cable.

I have to say that if we forget to turn off the mouse and keyboard, the receiver drains the battery really fast 😂. There was no Bluetooth then, and the early versions of Bluetooth were unsuitable for data transmission between computers and peripherals.

One Wireless Mouse and Its Receiver
One Wireless Mouse and Its Receiver

Looking at the HUGE CRT and chassis, having a laptop became my dream then. In this way, I could take it everywhere. Especially during summer and winter vacations, I could take it home 🤭.

CRT and Chassis
CRT and Chassis

After graduating, nearly all my computers are laptops. And due to Apple, most manufacturers are simplifying the ports on the laptop, so I have to make sure most of the peripherals should support Bluetooth. Then, due to the need for confidentiality at work, I had to ensure all Bluetooth devices could memorize multiple pairs to separate my personal laptop and office laptop so that I could conveniently switch one set of peripherals between my personal laptop and office laptop.

Is Wireless Always More Convenient than Wiredness?

However, due to the requirements of my employer and myself, my device management has become incredibly complicated 🤦. I need to ensure one set of peripherals can switch smoothly across four laptops and one chassis. Obviously, Bluetooth is unable to handle this.

By the way, owning five laptops is not weird. When I was working on a mobile project at my former former company, I had more than ten cellphones, several tablets, and four computers, but of course, nearly all of them did not belong to me but my employer. At that moment, there was no cloud testing platform for mobile projects, so all the tests needed to be processed on local devices.

Let’s get back to the main topic. Luckily most of the peripherals I had were dual mode, which means supporting cable and Bluetooth; this made me figure out a compromised solution. I connected the keyboard, mouse, and display to one multiport adaptor, and I could easily switch this adaptor from the currently connected computer to another chosen one. Since the COVID situation is not so intense, I sometimes need to go to the office. When I need to go to the office, I can unplug the display and put the laptop into my backpack with the adaptor, keyboard, and mouse.

Days ago, one question popped up in my mind. If a device named HDMI switch can switch the video sources smoothly, why is there not a device that can help us conveniently switch the peripherals across the computers? Then I found it, and it is KVM Switch. This KVM is not a Kernel-based Virtual Machine; it is the abbreviation of Keyboard, Video, and Mouse.

KVM switch (with KVM being an abbreviation for “keyboard, video, and mouse”) is a hardware device that allows a user to control multiple computers from one or more sets of keyboardsvideo monitors, and mice.

From Wikipedia
KVM Switch Diagram
KVM Switch Diagram

This switch really saved my life. I don’t need to leverage more than one set of peripherals to cover all my computers or don’t need to plug in and out whenever I switch across my laptops. This switch also makes my desktop tidier, although it is still not quite tidy.

Choose the Suitable KVM Switch

The type of KVM switches varies and is not easy to choose. If you want one, keep an eye on the tech specs, especially the HDMI part.

  1. Confirm the number of devices you would like to switch across.
  2. The type of USB ports. Due to the velocity gap between USB 1 and USB 2, consider it based on your own devices, such as whether you have external high-capacity storage devices or others.
  3. The type of HDMI ports. If you have devices supporting HDMI and Dolby Vision, such as Apple TV and Xbox Series X, please check whether your chosen KVM switch supports this. And HDR has several types of video formats, such as HDR, HDR 10, HDR 10+. The same as audio, its encoding varies.
  4. High resolution and refresh rates are pretty important for video and game enthusiasts.
  5. And also, hot-swapping affects the user experiences a lot.

Hopefully, this small talk can help guys with multiple computers a little.

Hammerspoon: one Swiss Army Knife on macOS

I may believe that most computers contain unique customizations, which may be why most people hate reinstalling the operating systems or setting up a new computer.

Such as my laptop, there are a bunch of tools that improve my experience using a computer. Here is a non-exhaustive list:

AppUsage
SizeUpCan easily attach the windows to the sides or corners of the screen. If the screen is big enough, you may put the documentation on the left and IDE on the right.
Pap.erIt can periodically and automatically set a beautiful sightseeing image as your wallpaper.
StretchlyTimely covers your screen to make you have a rest.
Lexico.comThe official site of the Oxford dictionary.
CheatsheetIt can show you the list of the selected application’s hotkeys.
New Terminal HereOpen a terminal with the current folder path.
One non-exhaustive list of my favorite tools

Besides improving my experience in using a computer, these tools also cause a few inconveniences, especially when I need to reinstall the OS and set up a new laptop. I have to look for an alternative because sometimes one is no longer free of charge, or sometimes one no longer supports the latest OS. This didn’t bother me much until I changed my Macbook Pro thrice in half a year. So I tried to find a way to minimize the number of tools I relied on, and I found Hammerspoon. I can say this is really a Swiss Army Knife on macOS.

Actually, there are some similar tools, but Hammerspoon finds the best balance between usage simplicity and functionality complexity. The users only need a little knowledge of Lua before customizing with Hammerspoon. Under the situation of no experience in Lua, I quickly finished the customizing based on the official documentation.

We can customize with the official spoons, such as windows manipulation.

-- We can quickly implement this with the WinWin spoon
hs.loadSpoon("WinWin")

-- Check whether WinWin is loaded and bind hotkeys to different directions.
if spoon.WinWin then
  -- Supporting symbol characters in the message of Hammerspoon is quite helpful. We will talk about this later. I will talk about this later.
  -- Side
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "left", "Window ⬅", function() spoon.WinWin:moveAndResize("halfleft") end) 
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "right", "Window ➡", function() spoon.WinWin:moveAndResize("halfright") end) 
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "up", "Window ⬆", function() spoon.WinWin:moveAndResize("halfup") end) 
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "down", "Window ⬇", function() spoon.WinWin:moveAndResize("halfdown") end) 
  -- Corner
  hs.hotkey.bind({"shift", "alt", "ctrl"}, "left", "Window ↖", function() spoon.WinWin:moveAndResize("cornerNW") end) 
  hs.hotkey.bind({"shift", "alt", "ctrl"}, "right", "Window ↘", function() spoon.WinWin:moveAndResize("cornerSE") end) 
  hs.hotkey.bind({"shift", "alt", "ctrl"}, "up", "Window ↗", function() spoon.WinWin:moveAndResize("cornerNE") end) 
  hs.hotkey.bind({"shift", "alt", "ctrl"}, "down", "Window ↙", function() spoon.WinWin:moveAndResize("cornerSW") end) 
  -- Stretch
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "C", "Window Center", function() spoon.WinWin:moveAndResize("center") end) 
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "M", "Window ↕↔", function() spoon.WinWin:moveAndResize("maximize") end) 
  -- Screen
  hs.hotkey.bind({"alt", "ctrl"}, "right", "Window ➡ 🖥", function() spoon.WinWin:moveToScreen("next") end) 
  -- Other
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "/", "Window Undo", function() spoon.WinWin:undo() end) 
endCode language: PHP (php)

It is pretty easy, right? Only several hotkey bindings to functionality are enough.

We can also create spoons with the API, such as BreakTime.

To implement this, we need to periodically use a page or image to cover the whole screen to make the guys in front of the PC take a rest.

Firstly, we can quickly start a timer with hs.timer:

obj.Timer = hs.timer.new(60, refresh)
obj.Timer:start()Code language: PHP (php)

Then, we can create a page covering the whole screen with hs.webview. Using a transparent image to make the page translucent is also not bad.

function makeBrowserOfBreakTime ()
  local screen = require"hs.screen"
  local webview = require"hs.webview"

  local mainScreenFrame = screen:primaryScreen():frame()
  browserFrame = {
     x = mainScreenFrame.x,
     y = mainScreenFrame.y,
     h = mainScreenFrame.h,
     w = mainScreenFrame.w
  }

  local options = {
      developerExtrasEnabled = true,
  }

  -- local browser = webview.new(browserFrame, options):windowStyle(1+2+4+8)
  local browser = webview.new(browserFrame, options):windowStyle(1+2+128)
    :closeOnEscape(true)
    :deleteOnClose(true)
    :bringToFront(true)
    :allowTextEntry(true)
    :transparent(true)

  return browser
endCode language: PHP (php)

Next, we can show and remove the cover with browser:show() and browser:delete() periodically with the timer.

function refresh()

  obj.curTime = obj.curTime + 1
  if obj.curTime > obj.microbreakInterval then
  
    obj.curMicrobreakCount = obj.curMicrobreakCount + 1
    if obj.curMicrobreakCount > obj.microbreakCount then
      hs.alert.show(obj.breakTime .. " minute break starts")

      local browser = makeBrowserOfBreakTime();
      browser:url("file://" .. hs.spoons.scriptPath() .. "BreakTime.html?time=" .. (obj.breakTime * 60 - 1)):show()
      hs.timer.doAfter(obj.breakTime * 60, function()
        if browser ~= nil then 
          browser:delete(); 
        end 
      end)

      obj.curMicrobreakCount = 0
    else
      hs.alert.show(obj.microbreakTime .. " second microbreak starts")

      local browser = makeBrowserOfBreakTime();
      browser:url("file://" .. hs.spoons.scriptPath() .. "BreakTime.html?time=" .. (obj.microbreakTime - 1)):show()
      hs.timer.doAfter(obj.microbreakTime, function() 
        if browser ~= nil then 
          browser:delete(); 
        end 
      end)
    end

    obj.curTime = obj.curTime - obj.microbreakInterval

  end
endCode language: JavaScript (javascript)

Load the BreakTime spoon in the same way to load the WinWin spoon, and start it. Done!

We can also customize the taskbar menu to improve the user experience.

Take BreakTime as an example. We can show the timeline of the next break.

BreakTime's Menu
BreakTime’s Menu

Besides this, we can also show all the hotkeys defined with Hammerspoon.

Menu showing all the hotkeys
Menu showing all the hotkeys

Hammerspoon supports symbol characters quite well, so users can make the menu items more attractive. Isn’t this amazing? 😄

obj.menubar:setTitle("⌨️")
obj.menubar:setTooltip("Hot Key Info")

local hotkeys = hs.hotkey.getHotkeys()
local menuItem = {}
  
for key, value in pairs(hotkeys) do  
  local item = { title = value["msg"] }
  table.insert(menuItem, item)
end 

obj.menubar:setMenu(menuItem)Code language: JavaScript (javascript)

Besides all the above, Hammerspoon still has much that needs going through. I am also keeping going through to make my customization more additional. Here’s mine.

BTW, not only reinstalling these tools, but I also need to reinstall all of the common applications such as VS Code, Plex, Sublime Text, VIM, etc. This is also terrible. Now I am maintaining a tap list containing the applications with homebrew. 😂