JSeaman

I have been involved in astrophotography for about ten years and I wish I had done this years ago so thought I would share my experience. I have literally only spent a couple of hours on it and feel like I’m as comfortable with it as any other software I spent months learning. There are lots of ways of achieving the same thing with this architecture but I found the following very easy and hope it helps kick start someone else into the Pi world, it’s really quite impressive!

I have a fixed observatory and always struggled with connectivity; I tried passive/active USB cables, Startech hubs, USB over Ethernet and probably other things I have forgotten. Some of them worked for a few months, some a year or two but nothing was truly reliable. I had also used various software tools from intervalometers to APT to PHD to Nebulosity to Cartes Du Ciel (CDC) etc. and they all had their quirks and issues too, essentially setting up was always a bit of a worry. Don’t get me wrong, most nights were perfect but then every now and then it would be a catastrophe.

I bit the bullet last week and decided I needed a Raspberry Pi in my life (it was a toss up between the more expensive ASIAir/NUC or the dramatically cheaper Pi and I took that option with zero regrets!). My concerns were around having to re-learn Linux stuff and all the software I had gotten to know as well as driver battles and lack of support. All these preconceptions were unfounded.

I bought the raspberry Pi and charger from https://thepihut.com/ which was £65 delivered next day for a Pi4 with 4GB RAM (which is plenty). I also got a metal case with heatsink and fan for £13 (here), a micro HDMI to HDMI cable for a couple of quid and a 64GB Class 10 SanDisk card for £10 off Amazon. So £90 and there is a complete PC at your disposal, a bargain!

The installation took literally a few minutes, I simply downloaded Astroberry which is free (here) which is the complete OS and software tools in one package. I flashed it onto a micro USB card using Balena Etcher (here) from my PC then plugged it into the Pi and up it booted. I was greeted with a Windows-esque GUI and ran one piece of software called KStars which allows me to do everything.

Note that you can do EVERYTHING remotely on the pi, on your desktop PC you just navigate to http://astroberry.local/desktop/ in your browser and you have a remote desktop style VNC connection and can work from there fully (password is astroberry when you press connect). I changed the password for the system and VNC but that is optional I guess. Just plug an Ethernet cable in and you are away, it can be done using wifi but the range is a bit limiting and I wanted something truly robust this time.

It looks like CDC or other planetarium software so you can look around, zoom in and out and select targets. It will ask for your location and allow you to download a few different catalogues which I did.

It needs all three lines, I guess different combinations of nearly right but not quite!

The solution:

#!/bin/bash
shutdown now
exit 0
 

Initially I did it with a terminal window but I also tried it with your commands above and it did the same with each.

Understood it's clearly not desired behaviour (and not what happens if I run the script directly) but I thought maybe leads to a permissions issue?

EKOS is running on the Pi but I am remote connected to the Pi via the astroberry.local/desktop URL so wondered if that was limiting my permissions?

Hi Stuart,

Thanks again, you're onto something - I tried various shutdown commands and changed the execute permissions etc. All had the same effect which is that it shuts down the Indi control panel (but only the control panel)

James

Ah amazing, I thought I had done something wrong - thank you very much indeed!

Oh thanks, is that https://indilib.org/forum.html

Surely this is what the script is supposed to be for though? I don't understand why you would need a separate board, it's just a line of code that needs to be run, do you have a link so I can check out the board you mean?

I'm hoping I have just got some bits to add to the script file but I'm not sure what

I did have a read of that earlier but couldn't see anything that pointed me in the right direction unless I missed something?

In terminal the sudo shutdowns require a passwrod but systemctl poweroff works fine, not sure if there should be any headers on the script file for ekos?

Thanks Julian, I tried both but no joy. I'm seeing a message to say it is doing it but nothing happens:

I am just entering the world of EKOS at the moment and trying to get a sequence for imaging set up. I have managed to unpark, take images and park again but I'd like to shut the pi down at the end. I assume the script circled below is the place to put it but I tried "systemctl poweroff" in a text file and that didn't work. Is anybody able to point me in the right direction?

If it has passed the meridian then don't tick the little box. Just tell it to slew to the target and it will know to do a flip, by ticking the box you're telling it not to do what it normally does

I stack individually and combine but you should have a try with the weighted entropy algorithm which is made for this (a bit like HDR on an SLR)

Cool you're on your way to a fantastic image...

That really was a quick play and mainly in photoshop, just a dbe in pixinsight which I didn't really need 

I would definitely suggest you check focus on each filter (even if they are supposed to be parfocal), I often have a little tweak to do

The processing is just levels and curves really, this is complicated by the fact that I was masking off the stars using layers but you wouldn't normally need that. eKep going, you're on the right path

2x2 binning hence the 6.45

Your Green, Blue and Luminance have quite bloated stars, I did a quick process by merging the red (quite clean) layer with the stars for the GB+L:

I use a manual filter wheel currently, I am more into imaging but you still need to change it when observing. I was using an EFW2 which is great but I love the simplicity of a manual filter wheel. I wouldn't dream of trying to change filters in the dark/cold now, very much recommended

I use a £10 laser collimator and it takes about 1 minute or less to do. I tweak it maybe once a month if that. I genuinely spend more time walking up and down the garden putting the Bahinov mask on

On 26/04/2021 at 23:45, Quetzalcoatl72 said:

I have a finderscope that's how I'm guiding, unless you mean a secondary one? I'm using a canon 600d it has x5 x10 zoom. I just unlock the clutches to move bright star into position, the only adjustments I make, unless I don't like a galaxy or nebula's position I may rotate the camera.

600D has live view doesn't it? You should be able to put that on and move the mount around

If you're using the finderscope for guiding then you could pop the guide camera off so you can use it to set the initial position easily without the need to plate solve

So essentially you would:

1. Slew to a target with Live View

2. Set up guiding calibration

3. Start guiding

4. Not touch anything

5. Take pics

If you neeed to rotate the camera, pause guiding, rotate camera, go to step 3

As you will have seen CDC = Cartes Du Ciel, works with EQMod to let you control the mount from a PC

What adjustments are you making by hand? EQMod will do slewing for you and yes it's free.

Do you have live view on the camera? In fact, what camera is it?

A finder scope might be a worthy investment to save you a lot of time. 

Agree on the plate solving recommendation too, that's a real time saver - take a picture of the sky, plate solve and it tells you where you are actually pointing so you can correct it

OK the black background with white stars is usually focus or too long an exposure, maybe reduce it down

Clouds will have a huge effect though

As soon as you're guiding don't touch anything, if you need to rotate the camera etc, pause guiding then start looping, reselect stars and start guiding again. Otherwise it will think the mount's moving as you do things and try to correct

Regarding the goto, do you use cartes du ciel or something? It would be worth clearing your alignment points, slewing to a bright star and then moving the scope there with the clutches off and calling this point 0

HEQ5/6 and ASI 120 2x2 guide scope from the logs

I see at 11pm you calibrated and started guiding, this worked for 1 minute and 35 seconds

It then started again at ~11:07pm, from your text above it reads that you started guiding then slewed the mount? You should slew to the target and then start guiding

It guided OK for about 15 minutes then stopped. The guiding looked good and the star mass was fairly steady, this looks OK up until here

At 11:30 ish it goes downhill, you start guiding again and have a really erratic star mass, was it cloudy? 

Recalibration at 11:45 was really good again (no issue with RA/DEC Orthogonality) but guiding was terrible, massive swings, I see you knocked it up to 2.5 seconds, did you change anything else?

At 1:22 another cal was attempted but this failed

So you had a patch in the middle which worked

Honestly I wouldn't dream of running this set up without one. And as a bonus you don't have to polar align again, you can be up and running literally within a couple of minutes on a good night. I think wind makes for a challenge at the best of times with a scope but these Newtonians really do suffer from it, a dome is great if you can but I had to replace my dome with an RoR due to sheer size. I'd definitely ask permission again