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Tag: programozás

My Old EQ3 with a New Hand Controller

The main piece of hardware, along with its testing devices

So here’s the problem: I like redundancy and I like control, fine grained, precise control of my devices. These are obviously not the aspects that drove me to choose the EQ3 mount when purchasing it, but since it is the mount I have at hand, and no physical room nor real opportunity for something better, I decided to hack this mount.

Independently of Hernán De Angelis who looks like he did a great job, from the same starting point — so kudos –, I got my hands dirty and my screen full of code. (tovább…)


My OBS keyboard – source code

So the whole thing is made in Arduino, one Attiny85 board acting as a USB client, a HID keyboard, and another board, a Nano (ATMega 328P) on the lookout for button presses. The two communicate via serial.

And the source code is published on github here (the USB-handling attiny85) and here (and the buttons-handling nano).

Below is the very first, unoptimized implementation, barely fitting onto the flash.



Moto-focuser for my MC 102/1300

Using my home standard, with the focusing controller mounted into a white box (not to be confused with the soapbox project, which is the auto-guider, also a home standard interfacing with the ST4 on the mount), this is the last tube of mine to be motorized. While the solution leaves no room for one’s head, unless a snail… the solution should work well for planetary photo.


Fotótervező 7. rész: a hasonló a hasonlót vonzza


Let’s Do Exoplanets

A simulated planetary transit, with the associated light curve

An amateur astronomer colleague of mine, Mátyás SZŰCS, got me inspired to look into exoplanets — once again. I already had a close encounter with distant solar systems, while looking into the Kepler measurements as published on the planethunters org website, going through some 4k stars of interest, of the some 160k that Kepler observed during its first mission.

I’ve never done observations of this kind before, maybe I never will. But I wanted to see what it is I could expect. I put together a naive simulation and then looked up some professional material to check for those into such stuff.

So I went for a rather naive approach here, went for numeric simulations in… well, PHP… with a color (rgb) selective limb darkening and planets with no atmosphere. The stars are simple, spherical, no polar brightening and no flattening, as with say Vega.

The interesting thing is the sharp drop between the first and second contacts and then the steady drop till the maximum — see below.




The Chess Clock

chess clock

Showing a 5+0 setup, 5 minutes main time with zero increment

At the end of this stupid year, ravaged by GovId-19 too, not just by covid-19, I put together a chess clock. Even though the number of people I can play with physically is really limited — obviously not everyone thinks, like me, that a calculated risk is worth a decent amount of freedom, poor old BF with who does or does not deserve what exactly — I just wanted to put together the clock, cause why not. Although it is a microsoft site, I published the project on github.

One thing a friend of mine noted: the lunch box… I find it one of the greatest challenges about home made gadgets to find the right box for them, without the 3d printer black magic. I also wanted this one to be transparent.

Another thing, more of a philosophical nature: the more I play around with arduinos, the more I realize how much effort went into the whole thing to be easy like a toy, instead of the PITA it could have been, to enable one to really create on top of an abstraction layer, in contrast with such mindfucks as that of  manually calculating the value of a register to attain a baudrate on some obscure microcontroller I ran into at work, because libraries, because bootstrapping, and because it’s the business logic we are focused on, not reinventing the wheels of bit counting. Really, it’s almost 2021.



Estimating the length of planetary videos

There’s a legend among amateur astronomers that, without derotation, Jupiter supports only 90 seconds of raw video. Anything above it: derotate.

It always felt fishy to me, even before I started doing planetary photography. Due to other reasons, like capturing the moons’ movement, and the interplay of shadows, I always tried to keep the videos short.

However, the subject is evergreen wherever there are newcomers. So, now I made the math, and since we are people, not mathboys, here’s a handy little table one can play with or scroll below, the same calculator loads into this article.



My Filterwheel Automation

Quite some time has passed since I automated my manual filter wheel, so now I write the article. I built this one mainly for fun, I could afford the (overpriced) automated version.

The specifications behind the whole idea

  • automate the manual filterwheel — without modifying the wheel itself, revert the changes should I get bored or if anything goes south
  • make it fail gracefully: the DC motor can be driven by anything outputting around 5V, a manual H-bridge and a couple of AAA batteries for example. Experience: the first version with the encoder failed due to the intense sunlight — hence duct tape and a paper cover of the window were added. Failing gracefully meant disconnecting the logic and connecting the manual H-bridge. No observation wasted.
  • make it compatible with my existing gear (the soapbox and the noszogtató)



Photoplanner: Close Neighbors

So I’ve been thinking about this: what if I want target proposals for objects that have a nearby neighbor. Like the Double Cluster, or  M81 and M82, or M35 and NGC 2158. So I came up with a generic filter in the photo planner that narrows the search results based on whether a particular result has a neighbor. The search switch is conjunction, and the unit is degrees, defaulting to 1 degree. Some searches (like an unpolite naked :conjunction) may still result in a server error (low memory), so the switch works on already specific queries.


Galaxies that have an obvious nearby friend:

type:galaxy minlum:11 conjunction:1

Open clusters and/or globular clusters that are near each other:

type:ogc :conjunction

Open or globular clusters or planetary nebulae with at least one planetary nebula in the pair. The curious cases of M46 and NGC 2818:

type:pnogc conjunction:0.7 conjunctiontype:pn minsize:0.005

The results are some pretty nice vistas.



My photo planner

a print from my planner

A few month back I ran into problems trying to identify certain deep sky objects that showed up on my pictures. Stellarium – although I like it – is good at searching for known objects, and not by coordinate search, and I cannot script it the way I want. is also a very useful tool, but it does not have all the objects I grew able to image. I built my own deep sky database, a strong search tool, but that one is a search tool only with no visual sky, although I linked it to Aladin Lite. Aladin and Simbad – I like them, but they lack an easy coordinate search – and I really mean easy when I say so. Obviously, Aladin and Simbad are mainly for professionals, I guess. Stellarium has a photo planning feature, but – even though it can show Aladin’s sky, still no button by default -, it doesn’t fit my hands. So I felt like everything I need is out there somewhere, but the dots are just not connected.

I wanted to have all my knowledge at my fingertips, everywhere, and finally to have a robust output, that doesn’t fail when going offline: paper. Needless to say, my thoughts converged towards a website.

So I wrote my own photo planner, based on the Aladin Lite API and my DSO search engine and Simbad’s coordinate search.



Jól kalibrált monitoron mindegyik számnál elkülönülő árnyalat látszik. Ha mégsem látszanak, akkor a megjelenített képek színhiányosan rajzolódnak ki. A monitort valószínűleg kalibrálni kell.

You should see distinct shades for each number. If those shades are not clearly visible, the displayed pictures will lack accuracy. Your display most likely needs to be calibrated (brightness, gamma, contrast etc.).