Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Webcam Mod wiring


malc-c

Recommended Posts

If you've gone that far, why not add the connectors like Gliders project? You can just plug the individual webcam boards directly onto it then - no soldering required (bar +5V / ground.)

Yeah that would be the ideal, even take it further and pcb mount the serial DB9 and SPST switch. If I was ordering with a decent batch size I'd use smd's and simplify it further. Regardless the usb, Q3 and LED (mic) will need (de)soldering. Three vs seven points, takes but a few seconds, it's a small pcb (with minimal drilling, did I mention I hate drilling?) that fits nicely in the MB1 box with an internal fan.

Link to comment
Share on other sites

  • Replies 210
  • Created
  • Last Reply

Just going through my bits boxes, I have almost everything but not the 11 volt zener. I have several 3.3v and 4.3v. I am bit rusty but I was going connect them in series; 3.3-3.3-4.3 = 10.9v, thoughts?

Sure I have done it before but its been about 20 years since I did anything like this.

Link to comment
Share on other sites

Not much to it really. Again, it just about having the tools. Laser printer for the pcb template. UV exposure unit (modified old scanner), bunch of nasty chemicals. Carbide drills and drill press, diamond chop saw or guillotine. A diy kit is doable I guess, I buy in minimum quantities from RS et al. Like the flexible solid core cable, comes on reels that cost a ton but lasts me a decade. Diodes by the 100 that sort of thing. You can buy small quantities from Maplins, but the unit price make me choke tbh.

Very impressed dude you wouldnt happen to have one of them nice boards spare that would make it a lot easier (cheeky i know but you got to ask aint ya)

Link to comment
Share on other sites

I just finished LX mod on my 900, used wire wrap approach, came out compact.

I have dead pixels (about 14) and some dust I think. Not a problem as I will only be guiding. I think you should be able to get rid of them with DSS, make sure you have Darks, Flats and Bias Frames and all your dead pixels should vanish, stars that coincide may be casualities.

Here is my dead pixel test, about 20 seconds and I allowed some light from the left.

post-24562-133877554996_thumb.jpg

Link to comment
Share on other sites

looking good guys...don't worry about dead or hot pixels.

If you are imaging, take some darks (same settings as your light (picture) frames but with the cover on the scope) and they will allow you to subtract the noise and dead pixels...along with other infringements in whatever programme you stack with.

and flats will take care of the gradient...

HTH

Link to comment
Share on other sites

no probs lee...i'm no expert on this, but there is plenty about darks, flats etc in the imaging section....pretty easy to do as long as you remember to use the right settings and makes a huge difference.

Looking forward to seeing the output from these sometime soon if the clouds break.

Link to comment
Share on other sites

wx seems to have no control! longer ex = no brighter

The version I have does : 1.8-1.

BTW does anyone know if it's possible to hardwire the SPC900 for LX mode? I would like to do away with the need for any additional connection as only need LX mode. I have checked the logic and it appears RTS goes from -11v to +10v when enabled, this only seems to change mod board output by - 0.5v, looks do'able but I am not clear on what the 900 logic is looking for to start listening to the LX settings via the USB.

post-24562-133877555186_thumb.jpg

Link to comment
Share on other sites

is lx not possible in day light with std lens just for experimenting?

Yes it is, I am doing it now with the the original lens fitted. I have to put it in a dark area and turn the gain down or it just 'whites out'.

I have built a 60mm F2.8 guide scope out of an old Aldi spotting scope objective and 2 reducer type lenses I had in my bits box; its very bright and compact. It's non-standard so fitting the 900 to it is going to be a challenge.

Anyone tried flashing the 900 to do RAW mode? Covered here: astrobond.ebrawe It looks good for imaging but I don't think I'll need it for guiding.

Link to comment
Share on other sites

I get an image but only in dim conditions, even with long exposure turned of in the software the ccd seems to be very sensitive so this mod seems to have done something even before I raise RTS. I can usually test my guide scope in the day but now I have to partially cover the objective or I just get a grey screen.

I assume the optional switch shown on the diagrams (previous page) allows an override, not sure as I haven't fitted it.

Link to comment
Share on other sites

Just looked through some of my images and I've got 5 dead pixels, one of which is really blue and bright ! - others are hard to see.

Not sure how the circuit could be modified to be permanently in LX with Amp off mode. My guess is that the modification is simply using the DTR / RTS lines to drive transistors that act as switches of the 5v line to pins / pads 8 and 13 etc. What's required is some investigation as to if these lines are pulled high when RTS is high or pulled low.... If that was the case then the transistors could be replaced, possible with a diode or resistor.... would need to get a scope / DVM out and do some testing after SGL6

Link to comment
Share on other sites

Thanks Malcolm, been doing some tests. I can see the shutter makes no difference I did some checking and I get the impression that RTS is being cycled to read out the CCD (can be seen in K3CCD LX setup), so now I think there is more going on than just pulling things up or down and leaving them there.

I have a solution anyway, I will run everything via USB (active cable) to the mount then break out to 1 serial port for the 900NC guide-cam, 1 serial for the 300D shutter, 1 parallel port for guiding the mount and 1 USB for 300D parameters. That will cover everything I need and all via one cable, all that lot are cheap Ebay.

Tony.

Link to comment
Share on other sites

hi just wondering if you could use this usb cable instead of going to a d9 then to a convertor?USB to TTL Serial Cable on eBay (end time 20-Apr-11 10:22:26 BST)

Also when i went to maplins they only had 1 bc548 transistor and so the bloke who was serving me said that these ones would be ok but an over kill Medium Power NPN Silicon Transistors : Transistors : Maplin

Link to comment
Share on other sites

hi just wondering if you could use this usb cable instead of going to a d9 then to a convertor?USB to TTL Serial Cable on eBay (end time 20-Apr-11 10:22:26 BST)

Also when i went to maplins they only had 1 bc548 transistor and so the bloke who was serving me said that these ones would be ok but an over kill Medium Power NPN Silicon Transistors : Transistors : Maplin

That's not the right type of USB to serial, it has no DTR or RTS just the data pair. Here is the correct type of USB to serial cable: USB 2.0 to RS232 Serial DB9 9 Pin Male Adapter Cable PC on eBay (end time 13-Apr-11 21:51:30 BST)

The transistor only needs to be any small NPN device, like this: Low Power LF NPN Transistors TO92 Case : Transistors : Maplin

Link to comment
Share on other sites

The TTL serial cable you linked to is to aid the prototyping or connection of a USB enabled microprocessor (such as the PIC 18F2550) - it is not intended to connect a standard RS232 serial port to a USB port as it has no conversion electronics that you will find in the item Roger the dodger linked to in the post above

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.