Category Archives: tech

tech stuff

grayscale #pylepton images to fake colors | #infrafred #thermography #imagemagick – #FLIR #Lepton

images come from the Flir Dev Kit bought from Coolcomponents.

First, in order to map the grayscale to colors, we need to generate a gradient.
This is how I did it, using ImageMagick.

convert xc:black xc:red xc:yellow xc:green1 xc:cyan xc:blue xc:white +append -filter Cubic -rotate 90 -resize 20x80\! gradient_IR_rainbow.jpg

this new gradient works like a charm

convert xc:white xc:yellow xc:red xc:green xc:cyan xc:blue xc:violet xc:black +append -filter Cubic -rotate 90 -resize 20x80\! gradient_IR_4-rainbow.jpg

Once you have the canvas gradient, you can use apply it to each image.

convert -verbose bike.png \( gradient_IR_rainbow.jpg -flip \) -clut -resize 500% fc_bike.png

Here are some of the images:

bikes1   fc_bikes1



bikes2  fc_bikes2



laptop-back1  fc_laptop-back1



laptop-front1  fc_laptop-front1



neighbor-house  fc_neighbor-house




i915 #glx issues #debian

sudo apt-get purge nvidia*
sudo apt-get install --reinstall xserver-xorg-video-intel libgl1-mesa-glx libgl1-mesa-dri xserver-xorg-core
sudo dpkg-reconfigure xserver-xorg
and then reboot ...

Source: here

installing munin with Debian

apt-get install munin munin node

chown munin:www-data -Rv /var/cache/munin/www


17 Order allow,deny
18 #Allow from localhost ::1
19 Allow from all
20 #Options None
21 Options FollowSymLinks

add file munin.conf to /etc/apache2/sites-available/

   ServerAdmin root@localhost
   DocumentRoot /var/www/munin
       Options FollowSymLinks
       AllowOverride None
   LogLevel notice
   CustomLog /var/log/apache2/access.log combined
   ErrorLog /var/log/apache2/error.log
   ServerSignature On

a2ensite munin.conf

this finally did the trick:

mv /var/cache/munin/www/ /var/www/munin

expect a few updates in the following days, beacuse

tail -f /var/log/apache2/error.log /var/log/munin/munin-html.log

is still giving a few errors

found the error:

munin.conf:9:htmldir /var/cache/munin/www

replaced by /var/www/munin


Adafruit’s ultimate GPS logger

Today I tested Adafruit’s ultimate GPS logger.
As usual, it was well documented on Adafruit’s site.

I took the first example from the tutorial and this was what I got:

Adafruit's ultimate GPS logger montage
Adafruit’s ultimate GPS logger montage

And here are the pictures from the soldering:
2014-04-23 16.58.08

2014-04-23 16.51.02

2014-04-23 16.50.55

2014-04-23 16.50.51

1.8″ TFT Adafruit display(ST7735) and Arduino uno


Install Adafruit ST7735 Lib and the Adafruit_GFX library for Arduino.

I had to upgrade ino to 0.3.6 in order to be able to build the example srcipts:

pip install --upgrade ino

I renamed the example files to .ino (’cause .cpp & pde gave errors)

Make sure you name the directories as in the documentation.

root@tortuguita:/usr/share/arduino/libraries# ls -lh Adafruit_*
total 36K
-rw-r--r-- 1 root root  13K Jul  5 23:51 Adafruit_GFX.cpp
-rw-r--r-- 1 root root 2.8K Jul  5 23:51 Adafruit_GFX.h
-rw-r--r-- 1 root root 8.0K Jul  5 23:51 glcdfont.c
-rw-r--r-- 1 root root 1.4K Jul  5 23:51 license.txt
-rw-r--r-- 1 root root  947 Jul  5 23:51 README.txt

total 40K
-rwxr-xr-x  1 root root  22K Nov  8 19:44 Adafruit_ST7735.cpp
-rwxr-xr-x  1 root root 4.7K Nov  8 19:44 Adafruit_ST7735.h
drwxr-xr-x 10 root root 4.0K Nov  8 19:44 examples
-rw-r--r--  1 root root 1.1K Nov  8 19:44 README.txt

Then I built it using inotool.

raspberry pi & telescope


  • Raspberry Pi model 2
  • TFT touchscreen
  • Adafruit TFT/camera Soft
  • Raspberry Pi camera module
  • Celestron First Scope
  • USB tablet charger
  • Disclaimer

     This is a _really_ low cost astrophotography device implementation, simple to build and not intended to do complicated (i.e. long exposition, tracking) photography. My main inspiration to build it was my nephew ;) ) 

    What we got is:

    rpi and celestron

    And what we see is:
















    source for TFT
    source for Adafruit software


  • how to fix the USB chager to the telescope (Hint: velcro)
  • how to fix the R-Pi to the telescope (Hint: see the rubber bands in the picture?)
  • how to fix the Pi Noir to the eyepiece (Hint: look too previous methods) DONE
  • I found this article that gave me the idea.