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Old 14-02-2017, 04:18 PM
rsevs3 (Ryan)
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Thanks Luka,

All of astronomy/AP has been a big learning curve, but man I have been loving it.

I agree about having another means of AP while i build something like this, I might get a webcam just to get me going, but I know full well I will quickly be longing for more than a webcam. I figure if I am going to drop some cash, I might as well get the best bang for buck that I can. Plus I am a sucker for DIY...

Scope is a SW 150/750 mounted on a EQ3 with tracking motors. I realise this mount is no good for long exposures, but one step at a time.

I am in the hills, in the Armadale area.

As far as the electronics go, I have been building/playing with them for many years including designing/making my own boards. Nothing at the level you guys are doing for board design though. Its been a while, but it is faster to refresh memory than to start from fresh. I should have most of the gear for building/testing my boards (soldering/rework station, variable psu, o-scope etc)

For the case, I dont think I will have too many issues. I have a small CNC router, have access to a lathe and mill and also access to a manufacturing shop through a mates business.

Hopefully I can be some help, but it could take a while to get up to speed on the camera and the AP thing in general. I will probably try to join a club or something to reduce the learning curve somewhat.
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  #582  
Old 14-02-2017, 06:53 PM
N_DD
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Quote:
Originally Posted by luka View Post
Didn't get any feedback regarding the ASCOM driver so I assume it worked fine? It has been cloudy and rainy here for a few weeks now so I could not do anything outside.
Hi luka,

sorry for the delay, I still didn't manage to upload the firmware and test your ASCOM driver (my 2 y. o. son decided to bring home a nice collection of viruses from the kindergarten!!!). How can I get access to the Google drive folder?

Nico
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  #583  
Old 14-02-2017, 11:05 PM
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Nico, hopefully things will get better soon. I know the feeling when kids bring all kind of sicknesses home. Luckily it is summer here so we are in the clear for a bit longer.
Do you have access to the whole Google drive folder? If not can you PM me your email address. The drive has all documentation about cam86 (and cam90) and the source code, also with my modifications.
Alternatively few posts above I posted an open link to a folder with the latest ASCOM drivers and firmware. This should be accessible by everybody.


Ryan, welcome to the club of DIY addicts
Sorry for the very short PM today but I had to rush out. You should have the access to our GD by now. The BOM file should have all the components listed and the Eagle CAD should have the build files.

It looks like you are very well geared up for building the electronics. I have few spare cam86 PCBs so you can have one if you want. Also there is a difficult to solder FTDI chip in LQFP-64 package. Let me know if you need help with this as I can solder it under a stereoscope. Otherwise you will need a magnifier of some sort to do it properly.
And for the machining of the case, clearly it should not be a problem for you. My resources for this are very limited (hand drill, hammer and few screwdrivers ) but some very nice people from IIS are helping me with the case.

One thing to keep in mind is that the Ukrainians have just released the build files for Cam90. It is very similar to Cam86 but with a 10Mpixel sensor (ICX493AQA instead of ICX453AQA). I am not sure about the noise levels but you may want to consider building this one instead of Cam86. Actually if you are considering Cam90 then I would advise waiting few weeks for the issues to be ironed out before starting. And few of us may do the build as well, not sure. The advantage is really only in megapixels which is not that important for AP.

Also few of us were (loudly) thinking of building Cam10 which is a guide cam. But this has not gone anywhere yet. Cam10 is much simpler than Cam86.

(Hope I did not scare you with all the different builds )

Regarding your gear, not all webcams are made equal for AP but the good ones are not cheap (I am not very knowledgeable on this). It may be easier and cheaper to mount your existing DSLR onto the scope, not sure. Nikon/Canon adapters can be easily bought for <$50, not sure about Sony. Webcam would be more suitable for planetary imaging... what is actually your AP interest (planetary, DSO)? You should have much darker skies than me (<5km from city).

Your mount will limit the exposure time but even then building this CCD will significantly reduce the noise (as it is cooled) compared to a DSLR. Also the unmodified DSLRs block a significant proportion of Ha which is not the case for us.
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  #584  
Old 15-02-2017, 12:28 PM
rsevs3 (Ryan)
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Thanks Luka. I was flicking through the GD yesterday.

I would be keen to grab a spare board if there are a few, saves having to get another batch made up. Unless there is enough interest to get another batch made with any revisions since the last lot was made.

Help would most definitely be welcome for the FTDI chip. I have one of those magnifying lights, but experience and the right equipment can make life a lot easier. I am sure some kind of beverage could be supplied to say

I had a quick look at the BOM, I was hoping to have more of the parts but it looks like I might only have some of the passives. Better some than none I suppose. I might start a spreadsheet on the drive to track what I need and if anyone down under needs some more parts can chuck them on that order (within reason of course )

I think I might go for a Cam86. It will give me a chance to get up to speed with you guys, get some experience with this kind of thing (my last CCD project was a failure). A Cam10 would be sweet as well, but i have to make a start on Cam86 before I worry about that.

My AP interests are everything that is in the sky, but I suspect that like most, I'm guessing, DSO will be the majority. There is just so much too see. I spoke to the place that my scope was purchased from to get the e-mount adaptor and they were going to have to start calling all their supplies. Im sure I could find one online but I have a webcam lying around that I dont use, so I started butchering that up last night just to get me started.

Last night while I was playing around with my webcam I had my first experience with dew. Got me thinking, the TEC for the CCD is a decent heat source. Would that have enough heat on the hot side to be used as a dew heater? I was thinking if it was water cooled with the scope as the heat sink. A closed loop water circuit that is bled up properly might not even need a pump, just convection could be enough to get the required flow. I have to stop getting ahead of myself.

Being so close to the city, it would be easy to get some viewing in and the go enjoy the nightlife. If you find yourself wanting some darker skies, hit me up and we can go explore the hills to find somewhere good.
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  #585  
Old 16-02-2017, 12:25 AM
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Hi Ryan,

You can have a spare board, no problems.

If anyone else is interested in doing the build please let me know now as there may be more spare boards.

There are two small issues with this PCB and both can be easily overcome:
- One capacitor is not in the right place and that this is causing noise. This was solved by scraping off the soldermask from one track and soldering the capacitor onto the scraped section, to move it. Not a big issue.
- Somehow the silkscreen only partially got printed on the boards so you will need to have a paper printout while soldering to see which part goes where.
Definitely not worth redoing the PCBs because of this.

I can also help you with some capacitors/resistors. Some cost only few cent but they are sold only in bulk packs, for example in packs of 100. This makes the cost per unit expensive (few $) when you really need only one or two. And there are several parts like this so it does add up quickly.

My BOM should be a good starting point and it has Element14 and RS components part numbers for most of parts. The stock levels are not accurate but you should be able to see what I have bought in bulk packs (marked in orange). Some parts have to be bough on ebay and it may take several weeks to arrive. The sensor comes from a donor Nikon D40, D50, D70 or D70s (not D40x!!!). Broken cameras on ebay can be bought quite cheaply if you are patient and the sensors from those cameras are usually fine.

Also consider getting spare parts (I got spares for the cheaper parts). For example, cam90 uses most of the same parts so if we ever go that way...

Did you buy your scope in Perth from a proper astro shop? If yes, which one? All the stores I know of are in the Eastern states so anything local certainly may have advantages.

Regarding using the heat from TEC to deal with dew, there are two main issues. One is the extra weight and the other one is the rigidity of the pipes. Also you get no dew control if you are not running the camera. Furthermore, without a pump there may not be enough cooling for the camera. Glen (glend from IIS) experimented with water cooling for his cold finger modded DSLR (with pump on the ground) and found out that the pipes are quite difficult to deal with.

The usual way to deal with the dew are heating tapes. I made mine with Nichrome wire (Jaycar stocks them) and duct tape. Resistor ladder is another way. There are plenty of recipes on google and they are really easy to make. There are also lots of ways to build a power supply, check the DIY forums on IIS. Mine is roughly based on Chris' idea from here. There are lots and lots of options, again, google is your friend. You could also get a cheap adjustable power supply and manually control the heating power.
But really the last few nights were quite extreme in humidity. Usually in summer there is hardly ever any dew here in Perth but you will need definitely something for the winter.
Another DIY project for you

Unfortunately there is no good viewing so close to the city as there is too much light pollution. Part of my motivation for this build is narrowband imaging which can be done from light-polluted areas. I'll definitely take you up on the offer to find darker skies but will need to sort out few issues with my mount. Also ATM I am using mains power in my backyard but moving to a darker skies will require portable power source of some sort. You will eventually also need something, for the camera and for the heating tapes to start with.


Again, if anyone else is interested in doing the build please let me know now as there may be more spare boards.
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  #586  
Old 16-02-2017, 02:10 AM
rsevs3 (Ryan)
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Thanks Luka, I will take you up on the bulk items. Plus it will help to reduce your cost/board. Win win.

I have just ordered the parts that you have listed as a ebay purchase (camera sensor and vertical driver), I should have those parts in the next couple of weeks. While I dont expect to be ready, I will potentially be in some fairly dark skies at the end of March and I would be annoyed if I was waiting on one part to be shipped.

I will just use your BOM and add a column for my own stock. Thats the plan anyway. Just have to pull my finger out and do a stock take on what i have here. I know I have a lot of the caps/resistors in the correct package sizes, I just have to confirm that they are the correct spec.

I got my scope from over east. I have not yet found anywhere locally that stocks much for scopes.

My thoughts with the dew control was to not have anything down to the ground but use a jacket around the scope with the flex water pipes zig zagging inside. Just an idea and wildly speculative on whether to would do anything at all. I will have a play around when I get something that moves some heat Good point about when the camera isnt in use, but you could still use a normal one during those short periods or when you are observing. I was just thinking more to try and reduce the portable power supply requirements.

There are so many things you can do DIY if you are so inclined. I have already been mulling over making my own mount... The hardest part is doing something to completion!

WRT portable power to go observing in the hills, I have 3 x 125AH (from memory) UPS batteries sitting here that you are welcome to use for the night. If you need more power than that then you had best buy a really long extension lead
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  #587  
Old 16-02-2017, 02:30 AM
N_DD
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Hi luka,

thanks, my son recovered now, but I am really looking forward for the spring to come!

I managed to flash the camera and test your ASCOM driver using APT: everything works, including the temperature controller. I have uploaded two 1s darks, this one with maximum read speed, while this one with slowest reading speed. No substantial difference in StdDev, so I think I will stay with fastest download speed for now.

Let me know when you can implement the "double reading" for getting rid of the charge accumulation!

Thanks,

Nico
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  #588  
Old 16-02-2017, 02:55 AM
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Ryan, regarding the end of March, you will be cutting it very close to have it completed. You can probably get the parts in and the electronics working, however the housing will require lots of thought to implement. The G106 case has to be modified and adapters made to fit the focuser. Also the case has to be hermetically sealed to keep moisture out. Our plan is to use silica gel inside to trap moisture and also to fill the case with dry gas (argon for example) before closing it. That will prevent condensation on the cold finger/sensor which will be at sub-zero temperatures.

The TEC we are using is TEC2-19003, from ebay as well. I waited over 4 weeks for mine, stuff from China usually takes 4-6 weeks. By the way, I have just uploaded a new BOM with the TEC model (last line of the file).

I do have a 3D printer and have printed myself a very simple housing which works fine but the sensor is not cooled. It also leaks light through as I only had red filament so I used black electrical tape around it. Enough to play around but with cooling the camera will go to the next level. If you finish electronics before your trip I could print one housing for you as well.

And regarding finishing DIY projects, see my post here.

Are the UPS batteries 12V?
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  #589  
Old 16-02-2017, 03:02 AM
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Hi Nico,
Thank you for testing the driver. Did you test the latest one (v0.3L driver and v0.2L firmware)?

Slowing down the speed of reading is useful if you see image corruption, for example horizontal or vertical lines in images. Some people have them and some don't. It is related to computer not reading data fast enough, however, it is not linked to the CPU speed, i.e. even new computers can have the problem.
If it works, keep the fastest reading speed. But make sure you check the images again if you change computers.

I did have the bias-before-image (probably) working but could not reproduce the problem here so I removed it from the driver. It should be easy to put back. I'll try to do it tomorrow.

Luka
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  #590  
Old 16-02-2017, 03:32 AM
rsevs3 (Ryan)
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Yeah I dont expect to have it finished, certainly not cooled or anything. I would be pretty happy if it was at the point that I could play around with it. Having said that, once I have seen a board and can more properly visualise the housing, I think I can design something fairly quickly.

I have a couple of TECs ordered too now.

I had read your warning the other day, a very lucky escape.

Yes, the batteries are 12v. I use them for power backup for my aquarium, but they are not being used while I adding the new aquarium. More DIY
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  #591  
Old 16-02-2017, 06:08 AM
N_DD
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Hi luka,

yes, I tried the latest firmware and ASOM driver, downloaded from the open link you shared few messages before.
Thanks, I will try the clearing option if you put it back. Hopefully there will be some clear night and I hope I can test it in the field!

Nico
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  #592  
Old 20-02-2017, 02:45 AM
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Hi Nico,

Sorry that it took so long but I had a food poisoning

I have modified the ASCOM driver to clear the sensor via a bias shot before exposures. In the settings there is a text box that you can enter time into. If the exposure is longer than this time then the bias will be taken (and discarded) before the exposure. This takes about 1.6s extra. The firmware may be able to do it faster but I still have not figured out the details how it actually works so at the moment we are just taking a 2x binned image before the real image. Binned so that the reading is faster.

For example, if you take 1s exposure and:
- the text box has >=2 then the total imaging time will be about 3s.
- the text box has 0s then the total imaging time will be about 5s.
The real duration of the exposure is shown in the bottom of the settings window.

Note that I could not test this as my cam86 does not seem to show the problem. The cam86 firmware actually does some sort of clearing of the sensor before every exposure but as Grim commented long time ago, it may not work too well. I am not sure why I don't see the issue.

Can you try and see how you go. It is hard to make any changes without being able to test anything. The new driver (cam86_v0.4L_setup.exe) is in the same folder as the old drivers. The firmware is the same as before.

Luka
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Old 21-02-2017, 07:11 AM
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Hi luka,

sorry to hear that, hope you recovered and that you didn't have too many troubles... food poisoning can be really annoying!

Thanks for the new ASCOM driver: I have installed it and everything seems fine. I will test the image clearing when I get a clear night: I found it difficult to clearly see any difference indoor, but on real targets I was seeing a lot of artifacts due to charge accumulation (like lots of star trails as a result of the previous slew!). I will let you know.
Meanwhile I am upgrading the TEC with a two-stages element, let's see if I can cool more efficiently the chip...

Thanks again,

Nico
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  #594  
Old 22-02-2017, 12:55 AM
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Thanks Nico, I am 99% recovered. I should have know better than to eat food from university cafeteria during holidays, who knows how old it was

I never tested the effect of the charge accumulation outside. We have a clear night tonight and I am just setting up for some DSLR imaging. If the mount plays along I will test my cam86 as well.
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  #595  
Old 22-02-2017, 02:57 AM
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Nico, I did not manage to see the effect of the charge accumulation.
1. I tried slewing (west to avoid trailing due to backlash in the mount), stopping slewing and then taking an image. Could not see any trailing.
2. I also tried shining a torch through the telescope, removing the torch and taking image - again no difference.

Now, at the moment my camera is not cooled - could this be the reason I don't see the effect? How big is the effect? What is the best way to observe this?
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  #596  
Old 22-02-2017, 04:49 AM
pat30 (Patrice)
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Luka, I have been absent for a while (traveling to the north country to see the aurorae )
I want to try your driver but I can not install it, the box opens again with gain and offset not the rest and In the choice it remains displayed in V1,while I deleted the old !!!!

I am attaching a schematic of an improvement to be done to avoid the disconnections of the CAM86 with the recent computers (win 10) we owe this trick to George a French constructor.
http://www.webastro.net/upload/minim...1487245087.jpg

Why my images do not appear on your forum?
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  #597  
Old 22-02-2017, 05:10 AM
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Hi Pat, welcome back. Hope you managed to see the aurorae.

Which filename was the driver you installed? On our Google Drive go to Luka_latest_ASCOM_driver and there you will find the driver called "cam86_v0.4L_setup.exe" and also the firmware called "cam86_fw_v0.2L.hex". That is the latest.
Sorry, I just realised there is also a folder called latest firmware which is probably where you are looking. Will sort the files out tomorrow, it is 2am here right now

With attaching of the images I usually click on the paperclip and in the new window click browse, pick an image and click upload. Once uploaded the image will be in the list in the window and then you can close the window.

I still do not have any cooling so I did not notice Win10 disconnecting from the camera.

Luka
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  #598  
Old 22-02-2017, 05:11 AM
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By the way, which debayering option do you use in APT?

The camera driver reports RGGB but in APT I get weird colours with this setting.
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  #599  
Old 22-02-2017, 04:05 PM
pat30 (Patrice)
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it's good:
Cam86_v0.4L_setup.exe and cam86_fw_v0.2L.hex that I installed but in the properties it remains in v0.1.

Yes I have seen auroras there are some pictures here, it is a magic show.
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  #600  
Old 22-02-2017, 04:32 PM
pat30 (Patrice)
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the matrix is GRGB
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