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Quorten Blog 1

First blog for all Quorten's blog-like writings

Why Raspberry Pi production capacity is so low, info on AA battery power and camera

quorten

2016-06-04

Categories: raspberry-pi   reiterate  
Tags: raspberry-pi   reiterate  

Okay, now time to search for some information on the Raspberry Pi Zero. What’s up with it? Why is the production supply so low? Here’s the answer: Raspberry Pi Foundation did not want to scale up the factory floor space required to keep up with the demand for Raspberry Pi Zeros, as it would have competed with their more-expensive Raspberry Pi 3 model’s factory floor space, right at the point in time when they were preparing to deliver their new model in February.

However, at least one good thing came out of this delay. During the hiatus, engineer was able to use the spare time to design in the much-asked-for Raspberry Pi camera connector.

DuckDuckGo raspberry pi zero production availability factory

20160603/https://www.raspberrypi.org/

  • Again, I reiterate, because this is important! I searched for this and found it, that means it’s important! The following article shows a photo of a Raspberry Pi Zero being powered by three AA lithium batteries. So indeed, it is definitely possible to use three batteries to power a Raspberry Pi, although you might be safer if you use 4 and the buck/boost switched-mode power supply.

Read on →

Great Raspberry Pi camera and great cost

quorten

2016-06-03

Categories: raspberry-pi  
Tags: raspberry-pi  

Wow, this is really interesting. I can get a better-than-iPad camera for the Raspberry Pi for a very good cost. 8 megapixel. About $25 dollars.

20160602/https://www.raspberrypi.org/help/camera-module-setup/
20160602/https://www.raspberrypi.org/products/camera-module-v2/
20160602/https://www.raspberrypi.org/products/pi-noir-camera-v2/

But do you know what’s really really interesting? I can also get a NoIR camera for the same price; that is, the same camera chip, but without the infrared filter (hence, No InfraRed, or NoIR for short). But, what makes this really really interesting is that I now have a really cheap way to do the obscure so-called “Scanning From Heating” technique whereby one can acquire 3D scans of transparent objects by heating up a spot on them and using heat differentials on an infrared camera to compute the geometry and material of the object in question. If you have any suspicions that there is an invisible man or otherwise lurking around, you could use such a scanner to confirm them, even if you cannot see this invisible being.

"Daubert process" used in Sleuthkit

quorten

2016-06-03

Categories: unix  
Tags: unix  

So, what is the Daubert case all about that spawned the so-named Daubert process? It happened in 1993, so it involved rudimentary computer hard drives, right? Wrong. It was only an argument over published scientific research methods.

20160602/http://www.sleuthkit.org/sleuthkit/desc.php
20160602/http://www.digital-evidence.org/papers/opensrc_legal.pdf
20160602/https://en.wikipedia.org/wiki/Daubert_v._Merrell_Dow_Pharmaceuticals,_Inc.

Great open-source 3D scanners, including advanced Raspberry Pi use, filesystem information and tools

quorten

2016-06-02

Categories: raspberry-pi   3d-scanner   unix   important  
Tags: raspberry-pi   3d-scanner   unix   important  

Important! 3D scanner notes.

So, if a super sleuth kit was already implemented by integrating lots of discrete open-source software, are Internet resources really that great? Search engines may be lousy, but in theory I could have found that sleuthkit on my own were I to peruse every single search engine result really carefully. Is it possible that a hybrid reflective-diode and laser 3D scanner implementation that I am planning on building is already on the Internet? Well, let’s see. Let’s start with the search query.

20160601/DuckDuckGo open source hybrid 3d scanner cheap laser

What do I find? Well, I refound one that I’ve already encountered before but decided was not good enough: MakerScanner. However, the technical details of the software implementation may prove inspirational.

20160601/http://www.makerscanner.com/

Wait, what? Fabscan? Somehow, that sounds more like what I’m looking for. I don’t know what it is about the name, it just sounds more on target.

20160601/DuckDuckGo fabscan 3d scanner

Read on →

Install Ansible via `pip`

quorten

2016-05-27

Categories: ansible   important  
Tags: ansible   important  

Important! Ansible notes. Install Ansible via pip:

pip install ansible

But, you’ll need sshpass installed first, and make sure that /usr/include/ffi.h exists, otherwise you should go install it per my instructions elsewhere.

yum -y install sshpass

Alternatively, you can use my ansible-virtualenv.sh script, available elsewhere.

More tricks to do with Python

quorten

2016-05-26

Categories: python  
Tags: python  

Important recurrent notes. More tricks to do with Python:

20160526/https://github.com/lihaoyi/macropy

This could be very important for creating Python 2 and 3 compatibility layers.

Python interactive history files

quorten

2016-05-19

Categories: python  
Tags: python  

How annoying is it that there is a ~/.python_history file written by Python 3? This was never the case for Python 2. Well, anyways, be glad that I told you that, so that you can be on the lookout for times where you might type in some testing code at the interactive debugging prompt, to find out that your secret tokens have been logged to a file that they weren’t supposed to go to.

Set up Rudel in newer Emacs and `paint.el` in older Emacs

quorten

2016-05-16

Categories: emacs  
Tags: emacs  

Emacs Lisp packages, there are so many interesting things you can do in Emacs if you have the right extension packages. But unfortunately, as fate must turn out, both Emacs and its packages have a drifting problem. Newer versions of Emacs come out with new features, therefore some new packages are incompatible with old Emacs. Alternatively, newer versions of Emacs also drop support for some older platforms, so sometimes older versions of Emacs really are required. Within these constraints, sometimes you can make simple source code modifications to bring your desired Emacs Lisp packages forward or backward a few Emacs versions.

So, let’s start with paint.el. A very small and simple one source code file package that allows you to draw pretty pictures in Emacs, just like you would draw on a whiteboard. The source code modifications for running in older Emacs are simple as follows:

;; Paint doesn't work so well in Emacs version 21 or earlier, but this
;; is how to get it up and running regardless.

(defun window-inside-pixel-edges (&optional window)
  (list 9 0 (* 7 80) (* 13 40)))
  (paint 512 512)

To setup Rudel on older Emacs, you need to byte-compile twice. The first time won’t successfully compile every single file.

Other notes on using Rudel. If you don’t choose a unique-enough color that can be seen even on an xterm, then you will get the error obby-color-in-use.